[show abstract][hide abstract] ABSTRACT: Brain histamine plays a regulatory role in feeding behaviour, acting as an inhibitory modulator. Portocaval anastomosis (PCA) is associated with cerebral aminergic systems alterations, including high histamine accumulation and release from neurons. Despite that, the rats with PCA eat significantly more, their body mass being lower than sham-operated animals. To disclose underlying regulatory mechanisms, food intake was measured before and after treatment with antagonists of histamine H(1) and H(2), orexin type 1 (OX(1)) and cannabinoid type 1 (CB(1)) receptors in adult male Lewis rats 6 months following the end-to-side PCA or sham operation. Hypothalamic concentrations of orexin A and histamine as well as serum concentrations of leptin, insulin and cholecystokinin (CCK) were analysed. PCA rats with body mass lower by 30%, have consumed more feed and water 150% and 200%, respectively. The modifying effects of pyrilamine, ranitidine, SB 334867 and rimonabant were less pronounced in PCA compared with sham-operated rats. Hypothalamic orexin A and histamine concentrations were higher in PCA rats than in the control group with intact portocaval system. In PCA rats, serum concentrations of CCK were higher, leptin concentrations lower, while there were no differences between the groups in insulin levels. In conclusion, the adaptive mechanisms efficiently render PCA rats less sensitive to peripheral and central anorexigenic signals. Orexin A appears to be involved in the counteracting mechanisms preventing further body mass loss in PCA rats.
Journal of physiology and pharmacology: an official journal of the Polish Physiological Society 08/2008; 59 Suppl 2:135-44. · 2.48 Impact Factor
[show abstract][hide abstract] ABSTRACT: Most of the Polish territory has been classified as an iodine-deficient and endemic goiter area according to the International Council for Control of Iodine Deficiency (ICCIDD) criteria. In 1997 the obligatory model of iodine prophylaxis was implemented. Our investigations were aimed at the effectiveness of iodine prophylaxis in Poland.
We assessed urinary iodine excretion and goiter prevalence in 5663 children aged 6-12 yr. The population of children from the same 27 schools was investigated from 1992 to 1994 (1406 girls and 1244 boys) and from 1999 to 2005 (1563 girls and 1450 boys) using identical laboratory and ultrasound methods.
We found significant increase in iodine urinary concentration (median 52 microg/l vs 93 microg/l, p<0.001) with accompanying drop in goiter prevalence (29.6% vs 5.2%, p<0.001) after implementation of iodine prophylaxis. Iodine excretion distribution changed significantly after 1997 with an increase in the percentage of children with iodine urinary concentration above 100 microg/l from 10.8% to 45.4%, respectively. A significantly higher iodine urinary concentration was observed in lowlands compared to uplands both before and after implementation of iodine prophylaxis (median, 50 microg/l vs 57 microg/l and 86 microg/l vs 114 microg/l, respectively, p<0.001). The goiter prevalence did not differ between girls and boys from 1992 to 1994 (28.8% vs 30.5%, p=0.35) and 1999 to 2005 (5.5% vs 4.9%, p=0.45).
Implementation of the new model of iodine prophylaxis in Poland in 1997 has led to significant increase in iodine urinary concentration and decrease in goiter prevalence among Polish schoolchildren. In the youngest group of children (6-8 yr olds), prevalence of goiter decreased to 3.2%--i.e. below endemic levels.
Journal of endocrinological investigation 05/2008; 31(4):309-13. · 1.65 Impact Factor
[show abstract][hide abstract] ABSTRACT: Biogenic mono-, di- and poly-amines are widely distributed among living organisms. The amines fulfil many important functions in the human body both in the periphery and brain. Some authors suggest that foods rich in biogenic amines, especially histamine, present high health hazards for consumers. However, this is conditional on a range of other factors. The alimentary tract is well equipped with enzymes that inactivate amines and the blood-brain barrier prevents them entering the brain from the circulation. Oxidative deamination, methylation, acetylation and transglutamylation are the degradation pathways which operate efficiently in the stomach, intestines and liver. Particularly important is oxidative deamination. Food histamine poisoning or cheese reaction, manifested itself in patients treated with drugs that inhibit amine oxidases or in patients showing an enterocytic diamine oxidase deficit. It is rather food allergy, which should worry us more, as endogenous histamine release from mast cells is more dangerous. Preventive measures should be undertaken against increases in food allergies.
Biochemical Society Transactions 05/2007; 35(Pt 2):349-52. · 2.59 Impact Factor
[show abstract][hide abstract] ABSTRACT: Concentrations of visfatin are increased in insulin-resistant conditions, but the relationship between visfatin and insulin and/or insulin resistance indices in pregnancy remains unclear. Insulin resistance in pregnancy is further accentuated in women with gestational diabetes mellitus (GDM). Thus we assessed serum levels of visfatin in pregnant women with varying degrees of glucose tolerance.
Fasting visfatin levels were measured at 28 weeks of gestation in 51 women divided according to their response to a 50-g glucose challenge test (GCT) and a 75-g OGTT: control subjects (n = 20) had normal responses to both a GCT and an OGTT; the intermediate group (IG; n = 15) had a false-positive GCT, but a normal OGTT; the GDM group (n = 16) had abnormal GCTs and OGTTs.
There were no age or BMI differences between analysed groups. Across the subgroups there was a progressive increase in glucose and insulin at 120 min of the OGTT (p < 0.01). This was accompanied by an increase in visfatin, from 76.8 +/- 14.1 ng/ml in the control subjects, to 84.0 +/- 14.7 ng/ml in the IG group and 93.1 +/- 12.3 ng/ml in the GDM group (p < 0.01 for GDM vs control subjects). There was a positive correlation between visfatin and fasting insulin (r = 0.38, p = 0.007) and insulin at 120 min of the OGTT (r = 0.39, p = 0.006).
An increase in fasting visfatin, the levels of which correlate with both fasting and post-glucose-load insulin concentrations, accompanies worsening glucose tolerance in the third trimester of pregnancy. However, the significance of these findings, and in particular the role of visfatin in the regulation of insulin sensitivity during pregnancy, remains to be elucidated.
[show abstract][hide abstract] ABSTRACT: Matrix metalloproteinases (MMPs) are implicated in numerous disease states including cardiovascular disease and cancer. Because recent studies have shown a detrimental effect of hormone replacement therapy on cardiovascular disease and breast cancer, we investigated whether there are any differences in the concentrations of MMPs and their tissue inhibitors (TIMPs) in women receiving various forms of postmenopausal therapy.
A total of 195 healthy postmenopausal women were assessed: 46 were taking tibolone, 47 were taking transdermal estradiol, 46 were taking conjugated equine estrogens (CEE), and 56 were not taking any menopausal therapy (CTR). Plasma levels of MMP-2 and -9 and TIMP-1 and TIMP-2 were measured by ELISA methods.
MMP-9 levels were significantly higher in the CEE group in comparison with healthy women not receiving menopausal therapy (P < 0.05). In contrast, MMP-9 levels in the tibolone group were significantly lower than in any other group (P < 0.01, compared with transdermal estradiol and CTR, and P < 0.001, compared with CEE). MMP-9 to TIMP-1 ratio was also significantly higher in the CEE, compared with CTR (P < 0.05), and lower in the tibolone group (P < 0.01, compared with all groups). MMP-2 levels were higher in the CEE group, compared with healthy women not receiving any menopausal therapy, and women taking tibolone (P < 0.05).
Our study demonstrates differential effects of various forms of postmenopausal therapy on serum levels of MMP-9 and MMP-2. It remains to be established whether these differences might be associated with differences in risks of cardiovascular disease and cancer in these women.
[show abstract][hide abstract] ABSTRACT: The complex processes of carcinogenesis often involve oxidative stress. Numerous indicators of oxidative damage are enhanced as the result of the action of carcinogens. Several antioxidants, with different efficacies, protect against oxidative abuse caused by carcinogens. Recently, melatonin (N-acetyl-5-methoxytryptamine) and related indoleamines have attracted attention because of their high antioxidant and anticarcinogenic activity. Some antioxidants, e.g. ascorbic acid, play an ambivalent role in antioxidative defense, since, under specific conditions, they are strongly prooxidant. Among known antioxidants, melatonin has been an often investigated experimental agent in reducing cancer initiation and inhibiting the growth of established tumors. The indoleamine has been shown to protect macromolecules from oxidative mutilation induced by carcinogens. In these studies, a variety of in vitro and in vivo models were used and numerous indices of oxidative damage were evaluated. The protective effects of melatonin and several other indoleamine antioxidants against cellular damage caused by carcinogens make them potential supplements in the treatment or co-treatment at several stages of cancer.
The International Journal of Biochemistry & Cell Biology 09/2001; 33(8):735-53. · 4.15 Impact Factor
[show abstract][hide abstract] ABSTRACT: Iodine prophylaxis in Poland started in 1935 and has been interrupted twice: by World War II and in 1980 for economic reasons. Epidemiological surveys carried out after the Chernobyl accident in 1989 as well as in 1992/1993 and in 1994 as a 'ThyroMobil' study, revealed increased prevalence of goitre in children and adults. Ninety per cent of Poland was classified as an area of moderate iodine deficiency, and 10%, in the seaside area, as mild iodine deficiency territory. Iodine prophylaxis based on iodisation of household salt was introduced again in 1986 as a voluntary model and in 1997 as a mandatory model with 30+/-10 mg KI/kg salt.
The evaluation of the obligatory model of iodine prophylaxis in schoolchildren from the same schools in 1994 and 1999.
Thyroid volume was determined by ultrasonography. Ioduria in casual morning urine samples was measured using Sandell-Kolthoff's method, within the framework of the ThyroMobil study.
Goitre prevalence decreased from 38.4 to 7% and urinary iodine concentration increased from 60.4 to 96.2 microg/l mean values between 1994 and 1999. In four schools the prevalence of goitre diminished below 5%. In 1999, 70% of children excreted over 60 microg I/l, and 36% over 100 microg I/l, whereas in 1994 the values were 44 and 13% respectively.
The present findings indicate that iodine prophylaxis based only on iodised household salt is highly effective.
European Journal of Endocrinology 05/2001; 144(4):331-7. · 3.14 Impact Factor
[show abstract][hide abstract] ABSTRACT: To examine the bromodeoxyuridine (BrdU) incorporation into DNA of thyroid follicular cells (TFC) in the remaining thyroid lobe after hemithyroidectomy (hemiTx) in 1, 2, 3 and 4 weeks time after surgery.
The experiment was performed on male Wistar rats. The Cell Proliferation Kit (Amersham, UK) was used in order to detect the incorporated BrdU. The BrdU incorporation was expressed as a BrdU labeling index (BrdULI; a number of BrdU-immunopositive TFC per 1000 TFC).
1. No statistically significant changes of BrdULI were observed between the particular groups of sham-operated (shamTx)-rats in 1, 2, 3 and 4 weeks time after surgery, and in comparison of each of them to the controls (at time "0"); 2. In the first 2-week period after hemiTx, an increasing effect of that surgical procedure on BrdULI value was observed (the highest BrdULI value was detected 2 weeks after hemiTx); 3. In the third and fourth week after hemiTx, a decrease of BrdULI value was observed, as compared to BrdULI groups (in 1- and 2-week time after hemiTx), and to the controls (at time "0"); 4. An increase of weight of contralateral lobe was shown in 1, 2, 3 and 4 weeks after hemiTx in comparison to thyroid lobe weight in intact rats.
During the first 2 weeks after hemiTx, the thyroid growth in the remaining thyroid lobe seems to ensue by hyperplasia mechanisms. The thyroid growth processes during subsequent 2 weeks (3rd and 4th) could result from other mechanisms - for example, from hypertrophy.
[show abstract][hide abstract] ABSTRACT: Cadmium is a well-known human carcinogen. Lipid peroxidation is involved in cadmium-related toxicity and carcinogenesis. Melatonin is an effective antioxidant and free radical scavenger. The potential protective effects of melatonin against cadmium-induced lipid peroxidation in hamster brain, heart, kidney, testes, lung, and liver were examined. Lipid peroxidation was induced by intraperitoneal injection of cadmium chloride [single dose of 1 mg/kg body weight (bw)]. To test whether melatonin would protect against the toxicity of the carcinogen, the melatonin was injected peritoneally at a dose of either 15 mg/kg bw or 5 mg/kg bw, 0.5 h before cadmium treatment and thereafter at 8 h intervals during the day in the 48 h interval following the cadmium injection. One group of hamsters received only a single melatonin injection (a dose of 15 mg/kg bw, 30 min prior to cadmium). Forty-eight hours after cadmium injection, lipid peroxidation increased in brain, heart, kidney, testes, and lung. Either multiple injections of melatonin at both the 5 and 15 mg/kg bw doses, or a single injection of 15 mg/kg bw, prevented the cadmium-related increases in lipid peroxidation in brain, heart and lung. Cadmium-induced lipid peroxidation in kidney was prevented by melatonin when it was given as a single dose of 15 mg/kg bw. Melatonin slightly, but not significantly, reduced cadmium-induced lipid peroxidation in testes. It is concluded that cadmium toxicity, at least with regard to the resulting lipid peroxidation, is reduced by administering melatonin.
Cell Biology and Toxicology 02/2001; 17(1):33-40. · 2.34 Impact Factor
[show abstract][hide abstract] ABSTRACT: This paper reviews the state-of-the-art on the management of thyroid cancer in humans, includ- ing the following thyroid carcinomas: papillary, follicular, poorly differentiated (insular), undiffer- entiated (anaplastic), and medullary (sporadic and inherited forms). Also metastatic (secondary) neoplasms of the thyroid gland have been approached. The rules of treatment (surgical, with use of 131 I and suppressive therapy with L-thyroxine) of particular types of thyroid cancers have been presented - both descriptively and by schemes. Furthermore, the role of genetic background in the pathogenesis of thyroid neoplasms has carefully been reviewed for papillary, follicular and medul- lary carcinoma. The paper constitutes a compendium of current views with respect to cytological and histopathological diagnostics of thyroid cancers.
[show abstract][hide abstract] ABSTRACT: To examine the dynamics of oxidative stress in patients with hyperthyroidism before and during the treatment with methimazole using the measurement of conjugated dienes, malondialdehyde, and Schiff bases in blood serum.
In eight female patients with diagnosed Graves disease and 8 healthy control subjects (7 females and one male) several parameters of oxidative stress (the level of conjugated dienes [CD], malondialdehyde [MDA] and Schiff bases [SB]) were estimated before and during the treatment with methimazole (Metizol -POLFA) as well as by hormonal and immunological tests. In addition, serum levels of TSH, free thyroxine (FT4), free triiodothyronine (FT3), antibodies against thyroperoxidase (anti-TPO) and thyroglobulin (anti-Tg) and low density lipoprotein-cholesterol fraction (LDL-Ch) were estimated.
We observed increased concentrations of free thyroxine (FT4) and free triiodothyronine (FT3), as well as of antithyroperoxidase (anti-TPO) and antithyroglobulin (anti-Tg) antibodies. At the same time, TSH level was significantly suppressed. The concentrations of thyroid hormones and of TSH normalised after the methimazole treatment. The examined parameters, i.e., CD, MDA, and SB, were evaluated as proportions of each of them to the level of low density lipoproteins-cholesterol fraction (LDL-Ch). This fraction of cholesterol contains many polyunsaturated fatty acids, being a substrate for the peroxidation of lipids. Additionally, the CD/MDA ratio was calculated.
The increase of the CD/LDL ratio in Graves hyperthyroidism and its normalisation in the course of the treatment with methimazole suggests that the drug can be protective against the oxidative stress induced by overproduction of thyroid hormones. The ratio of CD/MDA decreased in all the patients, as compared to the control group, showing a high speed of lipid peroxidation.
[show abstract][hide abstract] ABSTRACT: To examine thymidine kinase (TK - ATP: thymidine 5'-phosphotransferase, EC 188.8.131.52) activity in homogenates of rat thyroid lobes incubated in vitro with epidermal growth factor (EGF).
The thyroid lobes were collected from euthyroid, hypothyroid and/or hyperthyroid animals. Hypothyroidism was developed in the experimental rats by an administration of 0.1 % solution of propylthiouracil (PTU) in drinking water for 2 weeks, while hyperthyroidism was obtained by daily i.p. injections of L-thyroxine (50 microg/kg, B.W.), also for 2 weeks. After collecting, the thyroids were incubated for 4 hours in RPMI 1640 medium with an addition of 20 mM of Hepes buffer, 15% FCS, penicillin (200 U/ml), streptomycin (10 ug/ml) and with EGF (Sigma) (0.1 ng/ml, 10 ng/ml, 1000 ng/ml). The control lobes were incubated without any addition of EGF to the medium. TK activity was expressed as the amount of reaction products, measured by ascending chromatography.
1. in the absence of EGF, TK activity in the homogenates of thyroid lobes from hypothyroid rats was lower, while it was higher in the lobes from hyperthyroid animals, when compared to these obtained from euthyroid controls; 2. EGF in the concentration of 0.1 ng/ml or 1000 ng/ml decreased, while that in the concentration of 10 ng/ml increased TK activity in lobes collected from euthyroid or hyperthyroid rats; 3. in the tissue collected from hypothyroid rats, the addition of EGF (0.1 ng/ml or 10 ng/ml) caused a slight increase in TK activity versus hypothyroid controls - a tendency towards diminishing TK activity could be observed as parallel to increasing EGF concentration.
TK activity in the homogenates of rat thyroid lobes depends on the functional thyroid status and on applied EGF concentration in vitro.
[show abstract][hide abstract] ABSTRACT: Oxidative damage to the liver of lipopolysaccharide-treated rats was evaluated using four parameters: level of lipid peroxidation, changes in total GSH and GSSG concentrations and hepatic morphology. Bacterial lipopolysaccharide (10 mg/kg b.w.) was injected i.p. either at 6, 16 or 24 h before animals were killed. Lipopolysaccharide increased lipid peroxidation most dramatically when it is injected 6 h before killing. Hepatic total GSH increased after lipopolysaccharide in a time-dependent manner. The highest level of GSSG and largest GSSG/total GSH ratio were also observed in the group of animals injected with lipopolysaccharide 6 h before tissue collection. In a second study, lipopolysaccharide was injected 6 h before the animals were killed, with or without 1 mg/kg b.w. melatonin. Melatonin totally abolished lipopolysaccharide-induced increase in lipid peroxidation, exaggerated the rise in total GSH and reversed the increase in GSSG concentration. The liver showed obvious histological degenerative changes after lipopolysaccharide, effects that were counteracted by melatonin administration. The protection conferred by melatonin is presumably due to its antioxidant activity.
European Journal of Pharmacology 01/1996; 293(4):327-34. · 2.59 Impact Factor
[show abstract][hide abstract] ABSTRACT: We examined the effect of vasoactive intestinal polypeptide (VIP) on thymidine kinase (TK) activity in the tissue of rat thyroid lobes incubated in vitro. Additionally, thyrotropin, epidermal growth factor, as well as atropine and carbachol were studied. It was shown that: 1. thyrotropin and epidermal growth factor did not essentially affect TK activity; 2. the effect of VIP was dose dependent: the high concentrations of peptide (10(-7) M and 10(-5) M) suppressed, while the lower concentrations (10(-15)M, 10(-13)M, 10(-11)M and 10(-9) M)-enhanced TK activity; 3. atropine tended to increase TK activity, however, that rise did not attain statistical significance; 4. VIP, when used together with atropine, decreased TK activity when compared with the activity in question after exposure to atropine alone; 5. carbachol suppressed TK activity; 6. the joint action of carbachol and VIP did not significantly change the activity of the examined enzyme.
[show abstract][hide abstract] ABSTRACT: The effects of omeprazole--an inhibitor of gastric acid secretion--on gastrin (G)- and somatostatin (D)-cell density in the gastric antral mucosa epithelium in rats were examined, following a 5-day treatment. It was found that omeprazole increased the density of G-cells, whereas it decreased the density of D-cells. That effect was probably independent of hypergastrinaemia, since it could not be blocked by a simultaneous treatment with proglumide--a gastrin receptor blocker. It is concluded that the observed phenomenon is a direct result of a lower gastric acidity, as a consequence of omeprazole treatment.
Histology and histopathology 05/1992; 7(2):153-6. · 2.28 Impact Factor
[show abstract][hide abstract] ABSTRACT: The present study has been to test the effect of hydrocortisone (HC) on the mitotic incidence in adrenocortical cells of organ-cultured rat adrenal explants during a 24-hour incubation with or without angiotensin II (ANG). It was shown that HC significantly decreased the mean mitotic activity rate (MMAR) of adrenocortical cells in organ culture. That decrease concerned all the three cortical zone vs respective controls. In turn, ANG markedly increased the MMAR of the zona glomerulosa cells, when compared to the values recorded in controls, while there were no changes of the MMAR of the zona glomerulosa in the adrenal explants incubated with joint exposure to HC and ANG. The obtained results indicate that HC exhibits an inhibitory effect on the adrenocortical cell proliferation, which may suggest that arachidonic acid metabolites play an important role in the process of adrenocortical hyperplasia, their participation in the ANG-induced zona glomerulosa cell proliferation being strongly assumed.
Experimental and clinical endocrinology 05/1990; 95(2):197-202.
[show abstract][hide abstract] ABSTRACT: We have examined the effect of the thiol agent-cysteamine, known to deplete the hypothalamus, the pancreas, the gut of somatostatin--on the basal and TSH-stimulated mitotic activity of the thyroid follicular cells (TFC) in adult male rats in vivo. The animals of different groups were administered cysteamine alone (300 mg/kg BW, s.c.), TSH alone (2IU, i.p.), or cysteamine with TSH jointly, the former agent being injected 2 hrs prior to the latter. In order to evaluate the thyroid mitotic activity, the metaphase-arrest technique was used in the study. It was shown that: 1. TSH significantly increased the mitotic activity of TFC, as compared to controls, 2. cysteamine alone had no effect on the TFC proliferation, 3. unexpectedly, cysteamine, when administered 2 hrs prior to TSH, suppressed the stimulatory effect of TSH on the mitotic activity of TFC.