Comparative Biochemistry and Physiology Part A Physiology

Published by Elsevier
Print ISSN: 0300-9629
The 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) intestinal receptor was not detected in term fetal rabbits. This receptor was present at 2 weeks postpartum and its concentration reached a maximum at 4 weeks of age, and declined to adult levels by 10 weeks postpartum. The 1,25(OH)2D3 intestinal receptor concentration was elevated at 2 weeks postpartum in lactating rabbits, but returned to normal adult concentrations by 4 weeks postpartum. In rabbits of various ages, only minor changes in the equilibrium dissociation constant of this receptor were observed. These data indicate that increasing the small intestine 1,25(OH)2D3 receptor concentration is one mechanism by which the rabbit adapts to periods of increased calcium demand.
Stimulation of Mg2+, Ca2+ and Mg2+HCO-3 dependent ATPase activity in mitochondrial and microsomal fractions from the uteri of laying hens is demonstrated. ATPase activity was greatest with 5 mM concentrations of Mg2+ at pH 8.5, and at pH 7.4-7.8 following the addition of bicarbonate. Suppression of eggshell calcification, induced by insertion of a thread into the uterus, did not alter Mg2+, Ca2+ and Mg2+HCO-3 ATPase activities. Alkaline phosphatase activity was generally low, and was unaffected by suppression of eggshell calcification. Levels of carbonic anhydrase and calcium binding protein were lower in the uteri of hens laying shell-less eggs. Injections of 1,25(OH)2D3 in hens laying shell-less eggs did not alter CaBP levels or enzyme activities. It is concluded that factors other than 1,25(OH)2D3 and gonadal hormones are involved in the regulation of uterine CaBP levels.
1. The distribution of 25-hydroxycholecalciferol (25OHD3) and 1,25-dihydroxycholecalciferol [1,25(OH)2D3] in various organs from domestic pigs was examined by HPLC. 2. Plasma levels of both metabolites corresponded to those found in healthy human subjects. 3. Tissue concentrations of 25OHD3 in fat, kidney, liver, and intestinal mucosa were low (< 1/3 of plasma levels), whereas tissue concentrations of 1,25(OH)2D3 exceeded plasma levels by factors 3-7, adipose tissue concentrations being the highest. 4. Substantial amounts of activated vitamin D are stored outside the blood-streams and may actively participate in vitamin D and calcium homeostasis.
1. Capacity and affinity of duodenal 1,25(OH)2D3 receptors were measured in P depleted goats and in control animals kept on an adequate P supply. Plasma concentrations of Pi, Ca and vitamin D3 metabolites and activity of plasma alkaline phosphatase were measured to characterize the effects of P depletion. 2. During P depletion plasma Pi concentrations decreased significantly whereas plasma Ca and alkaline phosphatase activity increased. No changes were recorded for plasma vitamin D3, 25OHD3 and 1,25(OH)2D3 concentrations. 3. P depletion resulted in a significant decrease of the equilibrium dissociation constant Kd of duodenal 1,25(OH)2D3 receptors without affecting the maximum binding capacity.
The release of Ca2+ from the intracellular store site, as induced by inositol 1,4,5-trisphosphate, was studied in relation to free Ca2+ concentrations or amounts of stored Ca2+ in smooth muscle cells. The maximal Ca2+ release induced by inositol 1,4,5-trisphosphate was observed when the amount of Ca2+ in the store site was about 50% of the maximal capacity of the Ca2+ storage, and when the extravesicular free Ca2+ concentration was less than 1.5 X 10(-6) M. The Ca2+ release induced by inositol 1,4,5-trisphosphate was accelerated by ATP and 5'-adenylylimidodiphosphate (AMPPNP), but not by ADP and AMP. This inositol 1,4,5-trisphosphate-induced Ca2+ release appeared to be specific for intracellular Ca2+ store sites (mainly sarcoplasmic reticulum), and this Ca2+ release was not apparent in the sarcolemmal fraction.
1. The effects of somatostatin-14 (SS) and diazepam in vitro on the content of inositol-1,4,5-trisphosphate (IP3) in mouse spleen lymphocytes were investigated. 2. It was found that the exposure of mouse spleen lymphocytes in vitro to SS sharply diminished their IP3 level. 3. Diazepam had no effect on lymphocytes IP3 content. 4. The inhibition of phosphatydyloinositol (PI) breakdown was suggested as one of the mechanisms of the physiological SS action.
1.1. An intermediate molecular weight (1000–10,000 daltons) fraction from dog blood plasma containing several components of peptide nature was separated by membrane ultrafiltration.2.2. Molecular weight from this fraction isolated and purified peptides was found to be ranging between 1000 and 8000 daltons.3.3. The majority of these appear to be of a complex nature, containing one or more non-peptidic constituents attached to their polypeptide chains.4.4. Positive inotropic action of these peptides was investigated using papillary muscle preparation. Their relation to “Kinekard” and other related substances is discussed.
Nucleotides concentrations (ATP, ADP, AMP) have been measured in brain and muscle of eels exposed to 101 ATA of hydrostatic pressure (HP) for 3 hr. Survival times (ST) and oxygen arterial content (CaO2) have been measured in trouts exposed to HP = 101 ATA. The results show that at HP = 101 ATA, AMP increases (P less than 0.05) and ATP decreases (-12%; NS) in muscle but are not modified in brain; ST values are similar in normoxic and hyperoxic conditions, and CaO2 are similar at 1 ATA and 101 ATA of HP. It is concluded that HP tends to decrease aerobic production of energy. This phenomenon is not due to a failure in O2 transport from ambient medium to the cell but to a possible perturbation of the aerobic cellular processes leading to energy production (Krebs cycle and/or respiratory chain coupled to oxidative phosphorylation.
1. Specific high affinity binding of 2-[125I]iodomelatonin was detected in the brain of the pouch young of a marsupial, Bennett's wallaby. 2. Binding was rapid, stable, saturable and reversible. 3. Scatchard analysis indicated a single class of high affinity binding sites with an equilibrium dissociation constant (Kd) of 68 +/- 13 pM, a maximal number of binding sites (Bmax) of 0.7 +/- 0.1 fmol/mg protein and a Hill coefficient (nH) of 1.12 +/- 0.10. 4. Specific binding was inhibited by GTP (1 mM) indicating that the melatonin receptor is coupled to a guanine nucleotide binding protein, and by melatonin and closely related analogues with a potency order identical to that reported previously in the brain of eutherian mammals, birds and a reptile. 5. These studies suggest that the melatonin receptor is well-conserved through evolution.
Single injections of thyrotropin (TSH) increase serum T4 and thyroidal 32P uptake but not thyroidal 125I uptake regardless of dosage, exposure time or age. Chronic TSH exposure, with 3 or more days of injection, does increase thyroidal 125I uptake. Studies using iodine (I) supplementation indicated that the increased thyroidal radioiodine uptakes seen with chronic TSH administration were not due to an I deficiency in the thyroid resulting from high hormone release. Labeled and unlabeled experiments comparing the effects of single vs. multiple injections of TSH were used to describe the effects of TSH on hormone release, hormone production and thyroidal I uptake.
1. Binding sites for 125I-labeled endothelin (ET) isopeptides ET-1, ET-2 and ET-3 were visualized by autoradiography in the kidneys of man, baboon, rhesus monkey, tree shrew, pig and rat. 2. Highest levels of binding for the three isoforms were observed in the glomeruli, cortical and medullary vessels of baboon, rhesus monkey, pig and rat, whereas there was no noticeable labeling of glomeruli in human and tree shrew kidneys. 3. The enrichment of binding sites depended on the species and peptide investigated, suggesting different affinities and/or densities of a heterogenous population of renal ET receptors.
1. Muscle cation levels have been measured in severely affected and relatively unaffected muscles of dystrophic mice (129 ReJ strain) compared to control animals at various ages. 2. Muscle calcium levels were found to be elevated in the severely affected gastrocnemius muscles only at a late stage of the disease, calcium levels in mildly affected triceps muscles were unaffected. 3. Muscle sodium levels were elevated in both triceps and gastrocnemius muscles at all ages studied. 4. Muscle magnesium and potassium contents showed similar changes, being significantly reduced in the gastrocnemius from the time of development of the first signs of weakness (i.e. 3-5 weeks of age), this decrease becoming more marked with increasing age and showing a less marked, but significant, change in the triceps muscle at a later stage of the disease.
1. In six foals and their mothers (of Standard breed) diurnal changes in the haemoglobin level, red blood cell number and mean corpuscular haemoglobin during the first 13 weeks of foal life were studied. 2. Studies begun when a foal reached 7 days of age and were repeated every two weeks till 13 weeks of foal life. Blood was taken every 6 hr in foals and every 4 hr in mares. 3. No diurnal rhythmicity in parameters studied either in foals or in mares was found. 4. Decrease of haemoglobin level in lactating mares (14.0-12.5 g/100 ml) without changes in red blood cell number were observed. Mean corpuscular haemoglobin changed distinctly from one study day to another. 5. In foals were stated: significantly higher haemoglobin level and erythrocyte number and lower mean corpuscular haemoglobin than in mares.
1. In six standard-bred mares and their foals diurnal changes in the cortisol and glucose levels and in FDPA activity were studies for 13 weeks of foal life. 2. In the cortisol level diurnal rhythm was found in the 3rd, 7th and 11th week of foal life and in the 11th week of lactation in mares. 3. In mares the mean diurnal cortisol level changed from 32 ng/ml in the first week to 57 in the 11th week and in foals from 24 in the first week to 16 ng/ml in the 11th week. 4. In the glucose level no diurnal rhythm was observed. 5. In mares the mean diurnal glucose level after parturition was about 58 mg/100 ml and increased to 83-85 mg/100 ml. In foals it changed from 105 to 128 mg/100 ml. 6. In the activity of FDPA no diurnal rhythm was observed. 7. The mean activity of FDPA changed in mares from 3.3 to 4.4 U and in foals from 5.7 to 7.5 U.
1. The diurnal changes in the levels of lactic (LA) and pyruvic (PA) acids and values of pH were studied in standard-bred mares and their foals, for 13 weeks of foal life, throughout 2 years. 2. The studies began when a foal was 7 days old and were repeated every 2 weeks until foals reached 13 weeks of age. 3. Blood samples were taken every 4 hr for one day, each second week. 4. In the LA, PA levels and pH values no diurnal rhythm was stated in lactating mares during study periods. 5. In foals the diurnal rhythm in LA and PA occurred in the 3rd month of their life, with the acrophase at night hours. 6. The significant correlations between foal and their mother metabolites studied were observed. 7. The environmental factors (air temperature, humidity) influence fluctuations of the amplitude in parameters studied in the horse blood.
1. One litter of 12 pigs was used to evaluate the effects of hydrocortisone acetate injection on organ weight and carbohydrase activities. 2. Pigs were injected with hydrocortisone acetate or an equal volume of saline at 7 days of age and killed at 14 days, and tissues were collected, weighted, and analyzed for carbohydrase activities. 3. Hydrocortisone had no effect (P greater than 0.40) on daily gain, liver weight, spleen weight, or small intestinal length. 4. Hydrocortisone increased pancreatic weight by 29% and total pancreatic alpha-amylase content by 38%. 5. Hydrocortisone increased duodenal mucosal weight by 23%, duodenal lactase activity by 44%, duodenal maltase activity by 163%, and duodenal sucrase activity by 214%.
1.In owls, meal to pellet interval was directly related to meal weight and owls normally cast 1 pellet per meal; egestion of pellets in hawks apparently was associated with “lights-on” in the holding rooms regardless of quantity eaten and hawks normally egested less than 1 pellet per meal.2.All of the smallest raptors digested meals and egested pellets more rapidly than the larger raptors.3.The correlation between meal weight and pellet weight was only slightly better for owls than for hawks, but, because owl pellets contained more of the bones of their prey, they represented a greater proportion of the meal from which they originated.
1. Comparisons of left intraventricular end diastolic and systolic pressures, cardiac output, dP/dt, stroke volume and heart rate were made between the Bio 14.6 cardiomyopathic and F1B normal hamster at 45, 80, 150 and 240 days of age. 2. Comparisons of the ventricular calcium and taurine contents were made between the two strains of hamsters at similar ages. 3. Interstrain comparisons of the 240 day Bio 14.6 with age matched F1B hamsters and intrastrain comparisons with 45 day Bio 14.6 hamsters showed a decreased stroke volume, cardiac output and dP/dt with an increased left intraventricular end diastolic pressure, ventricular weight, ventricular weight/body weight ratio, heart calcium and taurine. 4. Despite the decreased left ventricular systolic pressure and cardiac output in the 80 day and older groups of Bio 14.6 hamsters, no compensatory increase in heart rate was observed.
1. Comparisons of the effects of 4 and 16 weeks of exercise were made on; cardiac output, stroke volume, heart rate, left intraventricular systolic and diastolic pressures, dP/dt, and heart calcium in the Bio 14.6 cardiomyopathic and F1 B hamsters. 2. In the cardiomyopathic hamster the cardiac output, stroke volume, left intraventricular systolic pressure and dP/dt, which were all depressed in the age related sedentary animals, were increased by both periods of exercise. The left intraventricular diastolic pressure which was elevated was likewise decreased by both exercise periods. Only the 16 week exercise period decreased the resting heart rate. 3. In the normal F1 B hamster, both periods of exercise increased the cardiac output and stroke volume while the left intraventricular systolic pressure was decreased. Only the 16 week exercise decreased the resting heart rate and left intraventricular diastolic pressure and increased the left ventricular dP/dt. 4. Both periods of exercise increased the total heart calcium in the Bio 14.6 hamster while the heart calcium in the F1 B was increased only by the 16 week exercise period.
1. Granule membrane protein (GMP-140) is an integral alpha-granule membrane glycoprotein, expressed on the surface of human platelets following degranulation, and is part of a new family of adhesion molecules (selectins) related to the endothelial leukocyte adhesion molecule (ELAM-1) and to the lymphocyte homing receptors in man (Leu-8/TQ1) and in mouse (gp90MEL-14). 2. The cross-reactivity with rat platelets of the monoclonal antibodies (MAb), LYP20 and S12, directed against human GMP-140 was examined, with the purpose of assessing the homology of GMP-140 between human and rat platelets and of using positive MAbs to detect platelet activation in vivo in response to vascular disease in rats. 3. By ELISA technique, LYP20 gave a greater OD reading with thrombin-stimulated rat platelets than with resting platelets. 4. 125I-LYP20 bound significantly more to thrombin-stimulated rat platelets (3875 +/- 750 molecules/platelet) than to resting platelets (645 +/- 240 molecules/platelet, P less than 0.01) with 50% maximum binding at 0.13 +/- 0.02 microgram/ml; 125I-S12 did not bind to rat platelets. 5. By fluorescence-activated flow cytometry there were significantly more fluorescent thrombin-stimulated platelets (56 +/- 7% of total), compared with resting platelets (8 +/- 1% of total, P less than 0.001). 6. Western blots of rat platelet lysates showed that LYP20 bound to a single band identified, under non-reducing conditions, as having the same apparent M(r) as GMP-140. 7. LYP20 immunoprecipitated a protein which became radiolabelled on the surface of thrombin-activated rat platelets; S12 did not recognize any protein.(ABSTRACT TRUNCATED AT 250 WORDS)
Samples of saccular macula from the rainbow trout were incubated in vitro with uniformly-labeled L-[14C]-glutamine, and radiolabeled products, released by potassium-induced depolarization in the presence of calcium, were examined. Most of the effluxed radioactivity was distributed in six (of 17) thin-layer chromatographic fractions. Fractions corresponding to aspartate and glutamate showed highly significant increases in radioactivity (as percent of total recovered radioactivity) during high-potassium treatment. Radioactivity in a fraction with an RF close to that of ornithine also significantly increased during potassium, and dropped sharply after potassium. The origins of the thin-layer fractions, with respect to sensory and neural elements in the saccular macula samples, are discussed.
1.1. When differences in body weights were allowed for, weight of the anterior pituitary glands and their FSH content were similar in both heat-acclimatized male rats and controls.2.2. l-Lysine-U-14C incorporation rate into testicular proteins was higher in heat-acclimatized animals at all temperatures studied. In this study, maximal value occurred at 36°C.
1.1. The tissue distribution of 14C-urea was investigated in rays and two marine teleosts.2.2. High levels of 14C-urea were detected in the extradural fluid (EDF).3.3. The time patterns in the EDF, CSF, sera, brain, kidney and gill show variations from these patterns previously reported for elasmobranchs.
1.1. The incorporation of 14C from uniformly labeled, 1-14C labeled and 3-14C labeled serine into various metabolic fractions in Trypanosoma cruzi has been studied.2.2. 14C from serine is incorporated into all major metabolic fractions, except the nucleic acid-containing fraction.3.3. The results suggest that T. cruzi is not extremely restricted with regard to the types of compounds it can produce with serine as a precursor.
Schistosoma mansoni male and female adults incorporated [4-14C]cholesterol in vitro. Males incorporated about three times more cholesterol than females. The major sites of cholesterol deposition in males were the tegument and parenchyma. The tegument and vitelline glands were the primary sites of cholesterol accumulation in females. In males, dorsal tegument showed greater cholesterol uptake than ventral tegument. Radiolabelled males and females transferred cholesterol to unlabelled members of the opposite sex.
Reversible specific binding of [14C]inosine has been demonstrated in turbot (Scophthalmus maximus) buccal tissues rich in taste buds. A highly significant correlation was found for a series of nucleosides and nucleotides between their feeding stimulant activity and their ability to displace bound [14C]inosine. It is concluded that the binding of inosine is the first step in the gustatory process.
1. The specific activity of expired 14CO2 was measured at rest and during 90 min treadmill exercise following an initial intravenous injection of D[U-14C]glucose. 2. The rate of CO2 production rose 4.5-fold during exercise in cocks but only 2.5-fold in females. The mean respiratory quotient was close to unity at rest and during exercise. 3. Estimated glucose turnover rate rose approximately 3.5-fold during exercise in cocks. Turnover rate did not increase in hens but the fraction of the glucose turnover oxidized to provide energy for the working muscles was increased. 4. It is concluded that carbohydrate sources account for the major fraction of energy expenditure during exercise of this magnitude and duration.
1.1. Body fluid and selected tissue distributions of exogenous, intravenously administered 14C-urea were studied in two elasmobranch species, Negaprion brevirostris and Squalus acanthias.2.2. Patterns of distribution were similar in the two species for equivalent time periods. Blood, cerebrospinal fluid (CSF) and kidney 14C-urea concentrations were high with similar patterns. Other body tissue levels, including the brain and extradural fluid (EDF), were only one-half to one-tenth the levels of blood, CSF and kidney.3.3. Quantitatively, species differences in 14C-urea concentrations were observed between N. brevirostris and S. acanthias. In general, 14C-urea tissue levels were higher in N. brevirostris than S. acanthias.4.4. In addition to the species variation, the distribution of 14C-urea differed in S. acanthias held at different temperatures and salinities. Brain and kidney values tended to be initially lower, and subsequently higher with increasing temperatures and salinities with time.5.5. In sharks a high CSF and low EDF distribution was observed.
1. An alternative method to the use of the disposable Kontes well for trapping 14CO2 produced in the course of biological oxidations is described. 2. A polyethylene miniature scintillation vial was used to contain the hyamine hydroxide-impregnated filter paper wick. 3. The two methods are compared in their abilities to trap 14CO2 produced directly by acidification of sodium [14C]bicarbonate and during beta-oxidation of 1[14C] palmitic acid. 4. The miniature vial and Kontes well methods showed similar efficiencies in the trapping of 14CO2 (97% and 95%, respectively, on average) the radioactivity of which was determined in the miniature vial using 5 ml only of scintillation fluid compared with a minimum of 10 ml required by the standard scintillation vial used to accommodate the Kontes well. 5. The technical advantages of the suggested miniature vial system, during both incubation and counting stages, are discussed.
1. Serum progesterone, estradiol-17 beta and cortisol, as well as cholesterol and cholesterol ester concentrations in pregnant and lactating rabbits (New Zealand white hybrids, n = 9), were measured. These parameters were also studied in the amniotic fluid, the milk and the fetal serum (28-day old fetuses). 2. Serum progesterone and estradiol-17 beta were significantly enhanced during gestation, while the content of cortisol showed a marked elevation at the end of pregnancy. The concentrations of these hormones decreased before parturition. 3. Serum cholesterol and cholesterol ester concentrations markedly decreased in the second half of gestation (74 and 76%, respectively) and elevated after parturition and in the first week of lactation.
1. Nonfaecal and faecal losses of Lichia amia were determined under controlled laboratory conditions at 15, 20 and 25 degrees C. 2. Ammonia-N was the major form of nonfaceal nitrogen excreted by L. amia and excretion rates were temperature-dependent. 3. The mass component b of the mass/ammonia-N excretion equation was temperature-independent and ranged from 0.63-0.65 and from 0.66-0.73 for starved and fed fish, respectively. 4. Mean nonfaecal energy loss (exogenous plus endogenous) was 3.78 +/- 1.99% of the ingested energy. 5. Assimilation efficiencies varied between individual fish and ranged from 61.24-93.79% (mean 80.76 +/- 7.14%) for dry matter and 87.52-98.22% (mean 94.09 +/- 2.22%) for energy. 6. The mean nonfaecal and faecal energy loss was 23.11 +/- 1.67% of the ingested energy.
Tre of the suricates exhibits a marked diurnal rhythm (mean Tre at night 36.3 +/- 0.6 degrees C and 38.3 +/- 0.5 degrees C during the day). Oxygen consumption is lowest at Ta 30-32.5 degrees C (mean 0.365 +/- 0.022 ml O2 g-1 hr-1); this is 42% below the value expected from body mass. At Ta below the TNZ, oxygen uptake rises rapidly, minimal thermal conductance (0.040 ml O2 g-1 h-1 degrees C-1) being 18% above the mass-specific level. Lowest heart rates occur at Ta 30 degrees C (mean 109.6 +/- 9.8 beats min-1) and oxygen pulse is minimal at Ta 30-35 degrees C with 40-45 microliter O2 beat-1. At Ta 15-32.5 degrees C total evaporative water loss is between 0.46-0.63 ml H2O kg-1 hr-1 and increases markedly during heat stress (to a mean of 5.35 ml H2O kg-1 hr-1 at Ta 40 degrees C). This rise of TEWL is mainly attributable to the onset of panting at Ta above 35 degrees C.
1. Concentrations of potassium and iron were measured in blood samples of 15 zoo-living Barbary sheep by atomic absorption spectrophotometry. 2. In analogy with the situation in Ovis it is suggested that a blood potassium polymorphism is also found in Ammotragus. 3. However, in the Frankfurt line at least, one of the presumed alleles is likely to be lost due to inbreeding.
1.1. The heart rate of an immature male harp seal was monitored by a telemetry system modified to function through a water-air interface.2.2. Heart rates were correlated with basic behavioural patterns recorded by closed circuit television.3.3. The behavioural patterns were studied and the most consistent pattern was chosen to represent spontaneous activity.4.4. Surface and submerged “free swimming” heart rates, and the variability of heart activity associated with respiratory pauses were observed.5.5. Distinct levels of heart rate were evident during spontaneous activity: a true surface swimming rate (122 beats/min), a level of bradycardia associated with sinus arrythmia (77 beats/min).6.6. The surface heart rate variance was much less than that for either a submerged seal or a ventrally recumbent seal.7.7. During spontaneous short dives the heart rate dropped to 40 per cent of the surface rate.8.8. Eighty-one per cent of these dives showed anticipatory bradycardia occurring 2·5–7·5 sec before the onset of submergence.9.9. Trained dives, however, produced a more profound bradycardia and less anticipation.
1. Heterozygotes TfF/TfE of voles did not differ in body weight, they had higher hematocrit value (males and females), higher beta-globulin fraction (males) or higher gamma-globulin fraction (females). 2. A smaller variability of parameters studied was observed in heterozygotes than in homozygotes. Small and similar variability occurred in hematocrit value and beta-globulins while higher variability occurred in body weight and gamma-globulins. 3. In common voles the faster migrating E system of transferrin may have a higher capacity for iron transport than the F system. 4. Seasonal changes of hematocrit value in vole populations seems to result from genetical and physiological variability. 5. Sexual and seasonal changes in beta-globulin level appear to be related to changes in sexual activity of the animals during the seasons. 6. In autumn, low weight of animals and high serum gamma-globulin level, with the same physiological variability of these two parameters, suggest the synthesis of gamma-globulins with tissue (muscle) proteins. 7. Autumnal increase of gamma-globulin level seems to be very important, taking into consideration the role of the protein in water retention and its filtration from the tissues. Very high level of the protein fraction may play a role in winter high mortality of voles.
Effects of long-term, low levels of exogenous estradiol-17 beta and dietary calcium on calcium metabolism and laying hen performance, and effects of serial blood-sampling, were studied. Significant 3-way (P less than 0.01) and 2-way (P less than 0.05) interactions involving sampling obscured possible main effects (Exp. 1); no main effects were found in absence of blood sampling (Exp. 2). Estradiol-17 beta appears to increase calcium utilization with very low dietary calcium only. Relatively small brachial vein samples taken only every 3-4 weeks have substantial confounding effects on interpretation of data.
The growth and differentiation of chick oviducts were caused by daily diethylstilboestrol (DES) or oestradiol-17 beta (E2) injections, and the effects of these oestrogens on the progesterone-induced production of a biotin-binding egg-white protein (avidin) were studied. In the DES primed oviducts, but not in the E2 primed ones, both DES and E2 administered with progesterone potentiated avidin production 2 to 3-fold, even after 10-day oestrogen withdrawal. The results suggest that DES and E2 prime the avian reproductive target tissue differently.
1. The diurnal pattern of urinary estradiol and creatinine excretion was investigated in order to evaluate the relationship between total estradiol excretion per day and the estradiol concentration or the estradiol-to-creatinine ratio from single urine samples in female common marmosets (Callithrix j. jacchus). 2. During a 36-day period, urine was collected from five adult female marmosets in 3-hr intervals during the light time of an LD 12:12 (400:0.1 lx) which corresponded to the animals' activity time. 3. Estradiol concentration was determined by radioimmunoassay after glucuronidase treatment and creatinine concentration was measured photometrically. 4. Concentration and amount of excreted estradiol, and the creatinine concentration showed a distinct diurnal pattern with significantly higher levels at the beginning of the activity time compared to later sampling times. 5. No diurnal pattern was present in the estradiol-to-creatinine ratio, but the difference between lower follicular and higher luteal phase levels of estradiol excretion remained significant in the 36-day period. 6. Correlation analyses revealed significantly positive correlations between the total estrogen mass excreted per day and the estradiol-to-creatinine ratio in "morning urine" samples. 7. Thus the estradiol-to-creatinine ratio of single urine samples collected at the beginning of the activity time provides a reliable estimate of total estrogenic output in this species. 8. Studies of the circadian pattern of urinary hormone excretion, however, require total urine sampling.
1. Administration of lysine-vasopressin (LVP, 1 IU/animal) strongly reduced electrolyte excretion in 24 hr urines of adult male Mongolian gerbils, but had no effect on free cortisol (C) or aldosterone-18-oxo-glucuronide (Aldo-gluc.) excretion. 2. (1-24) ACTH, given at a dosage of 20 IU/animal, increased C and Aldo-gluc. excretion but did not influence electrolyte excretion. 3. Fluid intake and potassium excretion were decreased in animals offered a control or a sodium-deficient diet; contrasting, excretion of C was stimulated. 4. In contrast to other rodents, Aldo-gluc. excretion showed no changes in Mongolian gerbils offered a sodium-deficient diet, but was diminished in animals either fed a control diet or given saline (154 mmol/l) as drinking water.
1.1. The sera of two species of Taterillus, T. gracilis and T. pygargus, were analysed by electrophoresis with different media: acetate, starch gel and acrylamide.2.2. The two principal fractions, albumin and transferrin, appear to have different mobilities according to the species and consequently can be used to differentiate these two species which are indistinguishable by the usual tests.3.3. The hybrids inherit albumin and transferrin from their parents and show two different fractions for transferrin and two different fractions for albumin.4.4. The chromosomal equipment of each species, 36/37 chromosomes for T. gracilis, 22/23 chromosomes for T. pygargus and 30 chromosomes for hybrids, bears out serological differentiations.
1. Animals fed a high energy ration had bigger body weight, and bigger heart, brain and genitals then animals fed a normal diet, but they had substantially smaller liver, kidneys, adrenals and thyroid glands than the otherwise smaller animals. Restricted feeding did not necessarily produce smaller organ sizes than normal. 2. The yearly variation in organ sizes was astonishingly large whereas the sex differences were rather rare. 3. For organs like liver, kidneys and thyroid glands the conclusion from the results was independent of the method of expressing the organ mass. The organ sizes seemed to be influenced by many coexisting factors like yearly differences, sex and age of animals, feed and farm.
Oxygen consumption (ml X kg-0.75/min) in relation to ambient temperature (Ta) in the raccoon dog whelps at the ages of 7-9 weeks and 17-19 weeks is described by equations y = 32.9-0.69x and y = 26.2-0.49x, respectively. The corresponding equations to adults in summer and winter pelages are y = 19.6-0.46x and y = 14.5-0.32x, respectively. The cooling constant (min-1) of deceased raccoon dogs decreased exponentially with increasing body mass, while M-0.75 specific heat transfer coefficient (W X kg-0.75/degrees C) regressed linearly on body mass, y = 0.124-0.00066x. Cooling rate of deceased animals were more dependent on body mass than on pelage quality.
1. Immunocytochemical analysis of bovine and human lung sections revealed the presence of the 41 kD intermediate filament protein cytokeratin 19 in microvessel and subpleural lymphatic endothelial cells as well as the mesothelial cell layer of the lung visceral pleura. 2. Cytokeratin 19 was expressed by human and bovine pulmonary microvessels with diameters ranging from 5 to 50 microns. 3. Cytokeratin 19 was also found in microvessels of the rete mirabile, an oxygen exchange organ of the eel. 4. Immunoperoxidase electron microscopy demonstrated cytokeratin 19 associated with the lateral membranes of adjacent bovine alveolar capillary endothelial cells.
Top-cited authors
Barbara Giordana
  • University of Milan
Vellea Franca Sacchi
  • University of Milan
Paolo Parenti
  • Università degli Studi di Milano-Bicocca
Roland Prinzinger
  • Goethe-Universität Frankfurt am Main
Peter Lüthy
  • ETH Zurich