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ABSTRACT: A quantitative assay method by LC/ESI-MS/MS for the simultaneous determination of MCP in cattle plasma was developed and validated. The chromatographic separation was carried out using a multimode column (2 mm × 150 mm, 3 μm) with gradient elution (0.05% formic acid/methanol with 0.05% formic acid). MCP and levosulpiride (internal standard) were analyzed in the precursor/product ion pair of m/z 300.1/226.9 and m/z 342.0/112.0, respectively. Linear calibration curves were obtained in the range of 2.5-500 ng/ml (R(2)>0.999) with a lower limit of quantification of 0.05 ng/ml. Mean recoveries were 96-103% and a coefficient of variation was less than 6.5%. Plasma MCP concentrations after 0.4 mg/kg intravenous administration to 12 cattle were determined by the LC-MS/MS method.
Journal of Veterinary Medical Science 11/2012; · 0.85 Impact Factor
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ABSTRACT: The responses of 64 Holstein cows with milk fever to first treatment with 500 ml of either of two intravenous calcium (Ca) solutions, one containing Ca alone (group A, n=32) or one containing Ca, phosphate, and magnesium (group B, n=32), were evaluated by selected clinical signs and serum biochemical data. Based on the cow's ability to stand, treatment response was categorized into "immediate response" (stood after single treatment), "delayed response" (stood after repeated treatments), and "non-response" (slaughtered despite repeated treatments). No significant differences among the response categories were found between the two groups, suggesting that the solution containing Ca borogluconate alone was sufficient for the first treatment of milk fever.
Journal of Veterinary Medical Science 10/2012; · 0.85 Impact Factor
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ABSTRACT: To compare the use of a single-sample method involving IV administration of iodixanol with a multisample method involving inulin for the estimation of glomerular filtration rate (GFR) in cats.
24 cats, including 15 healthy cats and 9 cats with naturally occurring renal diseases.
Each cat was coadministered iodixanol (a nonionic contrast medium; dose providing 40 mg of I/kg) and inulin (50 mg/kg), IV, and blood samples were collected 60, 90, and 120 minutes later. Serum iodixanol and inulin concentrations were determined by means of high-performance liquid chromatography and colorimetry, respectively. Serum urea nitrogen and creatinine concentrations were also measured.
Analysis of the data from healthy cats and cats with naturally occurring renal diseases revealed an excellent correlation between GFR values estimated by the multisample and single-sample methods with iodixanol. Likewise, GFR values estimated from the single-sample method with iodixanol were closely correlated with those calculated from the multisample method with inulin.
For estimation of GFR in cats, use of a single-sample method with iodixanol, instead of a multisample procedure, may be an expedient tool in both clinical and research settings because of its benefits to patient well-being as a result of reduced stress associated with blood sample collection.
American Journal of Veterinary Research 09/2012; 73(9):1344-9. · 1.27 Impact Factor
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ABSTRACT: An interventional ultrasound technique to increase the safety of surgical treatment of the calf forelimb was tested. First, the brachial plexus was evaluated using ultrasonography and then 2% lidocaine was injected under ultrasound guidance. Ultrasonically, the brachial plexus appeared as multiple hypoechoic areas surrounded by a hyperechoic rim or a hyperechoic structure characterised by multiple discontinuous lines. It was located between the omotransverse muscle and axillary artery and vein. The sensitive effect in the forelimb was seen mainly in the area supplied by the musculocutaneous nerve, indicating successful blockage in the nerve plexus. Out of the eight forelimbs, the motor effect was observed in seven forelimbs. These results suggest the clinical feasibility of ultrasound-guided brachial plexus block in bovine medicine, although further studies are needed to examine various approaches, including the sites of needle insertion and the appropriate volume and dosage of anaesthetic.
Research in Veterinary Science 06/2012; 93(3):1467-71. · 1.65 Impact Factor
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ABSTRACT: The objective of this study was to determine the potential influence of fluctuations in the sex hormones progesterone and oestradiol-17β (E(2)), on biomarkers of bone resorption (hydroxyproline [HYP] and tartrate-resistant acid phosphatase isoform 5b [TRAP5b]) during the oestrous cycle of Holstein cows. Over the course of the study, plasma HYP concentrations did not change and alterations in the concentration of TRAP5b negatively correlated with E(2) levels: enhanced TRAP5b activity correlated with decreased E(2) concentrations below a defined level. This finding enhances the understanding of calcium homeostasis in post-partum dairy cows.
The Veterinary Journal 05/2012; · 2.24 Impact Factor
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ABSTRACT: Dose responses of plasma calcitriol, calcium (Ca), bone metabolic markers and glomerular filtration rate (GFR) were evaluated in four nonpregnant Holstein cows treated subcutaneously with an aqueous formulation of calcitriol at four doses in a 4 × 4 Latin-square design. Calcitriol, Ca, and markers of bone metabolism were analyzed in plasma samples. GFR was measured in predose and day 5 samples. Plasma calcitriol and Ca concentrations increased dose-dependently. The calcitriol dose was positively correlated with the area under the concentration-time curve of plasma calcitriol. Bone formation markers tended to increase from day 3 onward for all doses. No significant changes in GFR were noted. Thus, exogenous calcitriol administered between 0.0625 and 0.5 µg/kg body weight elicited dose-dependent increases in both plasma calcitriol and Ca and elevated bone formation markers without affecting renal function in nonpregnant cows.
Journal of Veterinary Medical Science 11/2011; 74(4):473-6. · 0.85 Impact Factor
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ABSTRACT: To develop a simple procedure for estimating glomerular filtration rate (GFR) in calves, a three-sample method using iodixanol was first compared to that using the standard agent inulin. Iodixanol and inulin were co-administered intravenously to calves at 40 mg I/kg and 40 mg/kg, respectively, and blood was collected 30, 60, 120, and 180 min later. Serum iodixanol and inulin concentrations were separately determined by high performance liquid chromatography and colorimetry. Serum urea nitrogen (UN) and creatinine concentrations were also measured. GFR estimated by iodixanol was consistent with that using inulin in clinically healthy calves. Based on GFR estimations in healthy calves and those renal-loaded with iodixanol, it was found that the serum creatinine concentrations became elevated when GFR decreased to 60% of the reference value. In contrast, serum UN concentrations fluctuated widely, presumably due to extra-renal factors. When GFR was estimated using the three-sample method and compared with the single-blood-sample method, 62/69 (90%) of samples tested were within the agreement plots. The results demonstrated that the single-blood-sample method using iodixanol may be useful in monitoring GFR in calves.
The Veterinary Journal 11/2011; 193(1):174-9. · 2.24 Impact Factor
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ABSTRACT: A colorimetric assay used to quantify the non-ionic contrast medium iodixanol in sera was validated and compared with high-performance liquid chromatography. The application of this assay to estimate glomerular filtration rates (GFR) in cattle was examined. Serum iodixanol was de-iodinated by alkaline hydrolysis and the amount of released iodine was subsequently determined using a ceric arsenite method. There was a close correlation between the two methods using identical specimens. In clinically healthy cattle with different body weights, the reference value (166.3-178.8 mL/min/m(2)) based on body surface area was fairly stable as compared with that (2.13-3.63 mL/min/kg) based on body weight. Based on GFR data in healthy and renal-impaired cattle, when the GFR decreased to more than 60% of the reference value, serum urea nitrogen and creatinine concentrations increased. The colorimetric assay is a simple method for the estimation of GFR in cattle and requires no expensive equipment.
Research in Veterinary Science 09/2011; 93(1):378-80. · 1.65 Impact Factor
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ABSTRACT: To evaluate serum clearance of iodixanol, applicable to the estimation of glomerular filtration rate (GFR), clinically healthy and experimentally-induced nephropathy calves were prepared. Iodixanol was administered intravenously at 40 mg I/kg, and blood was withdrawn 60, 120, and 180 min later. Serum iodixanol concentration was determined by high-performance liquid chromatography. No statistical difference in GFR was noted between strains (Holstein vs. Japanese Black) or sexes, and the α(2)-adrenergic agonist xylazine increased GFR. In calves subjected to right renal vessel ligation, followed by a left nephrectomy, a marked reduction in GFR was observed with renal ischemic changes. These results suggest that the GFR estimation by serum iodixanol clearance is a ready-to-use tool in calf research and practice owing to the ease of monitoring serial renal function.
Journal of Veterinary Medical Science 07/2011; 73(12):1625-8. · 0.85 Impact Factor
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ABSTRACT: To estimate the glomerular filtration rate (GFR) in horses, an optimum dose of the nonionic contrast medium iodixanol as a tracer was assessed with blood-sample times. Iodixanol was administered intravenously at 10-40 mg I/kg to geldings and mares, and blood was collected 30, 60, 90, 120, 150, and 180 min later. Serum iodixanol concentration was determined by high-performance liquid chromatography (HPLC), and serum urea nitrogen (UN) and creatinine concentrations were also measured. The combination of 20 mg I/kg iodixanol and sampling times of 60, 90, and 120 min after injection was considered to be appropriate for practical use. In clinically healthy horses, the reference values were determined to be 1.90 ± 0.03 ml/min/kg (150.8 ± 2.94 ml/min/m2), consistent with historical data using different tracers. The result suggests that serum clearance of iodixanol is a ready-to-use tool for a screening of alterations in the equine GFR, although it is necessary to perform a more longitudinal study using horses with a variety of renal functions.
Veterinary Research Communications 05/2011; 35(7):463-8. · 0.82 Impact Factor
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ABSTRACT: To better understand species differences in cisplatin nephrotoxicity, we focused on renal cysteine-S-conjugate β-lyase (C-S lyase), which may play a crucial role in the metabolism of platinum (Pt)-cysteine conjugates. Aminooxyacetic acid hemihydrochloride (AOAA), an inhibitor of C-S lyase, reduced renal injuries due to cisplatin in rats, suggesting involvement of C-S lyase. On day 5 following a bolus cisplatin injection, three species showed in vivo nephrotoxic potentials in the order of rats>mice=rabbits (the highest to lowest), based on body surface. The levels of renal Pt residue at the nephrotoxic dose were in order of rabbits>rats>mice. Meanwhile, the activity of endogenous (basal) mitochondrial aspartate aminotransferase (AST), one of the C-S lyases, in the renal cortex of naive animals was rats>mice=rabbits. In a qualitative Western blot analysis, expression of mitochondrial C-S lyase in the kidney was observed at approximately 37kDa in all five species used. In in vitro studies, the cytotoxicity of cisplatin was dependent on the expression level of C-S lyase mRNA in the respective renal cells. These results demonstrate that species differences in cisplatin nephrotoxicity are attributable to an interaction of renal Pt transition with C-S lyase activity.
Food and chemical toxicology: an international journal published for the British Industrial Biological Research Association 05/2011; 49(9):2053-9. · 2.99 Impact Factor
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ABSTRACT: To elucidate the effects of an exogenous calcitriol (1,25-dihydroxyvitamin D(3)) on plasma bone markers, the formation item osteocalcin (OC), undercarboxylated OC (ucOC) and bone-specific alkaline phosphatase (BALP), and the resorption parameter tartrate-resistant acid phosphatase isoform 5b (TRAP5b) and hydroxyproline (HYP) were measured in conjunction with plasma calcitriol and calcium (Ca) concentrations in dairy cows receiving calcitriol or its vehicle according to a 2×2 crossover design. Calcitriol (0.5 μg/kg, i.m.) increased significantly its plasma level during 6 h to day 2 and plasma Ca concentration during 12 h to day 7 compared to the vehicle. Also, plasma OC and ucOC started to rise from day 3 and 1, respectively, and remained elevated until day 7. No change in plasma BALP, TRAP5b or HYP associated with calcitriol treatment was noted. These results demonstrate that exogenous calcitriol stimulates osteoblasts to biosynthesise OC, a determinant of the bone formation in cows.
Research in Veterinary Science 02/2011; 90(1):124-6. · 1.65 Impact Factor
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ABSTRACT: To estimate the glomerular filtration rate (GFR) sequentially in conscious rats, we validated a single-blood-sample method using a bolus injection of the nonionic contrast medium iodixanol as a tracer. First, to clarify basal age-related GFR profiles, iodixanol was intravenously administered once weekly at 1500 mg kg(-1) I to clinically healthy male F344 rats from 6 to 15 weeks of age. The blood sample was collected 120 min later, and serum iodixanol concentration was measured by HPLC. GFR values decreased gradually by 9 weeks, presumably due to rapidly increased body weights, and then remained constant from 10 weeks onward. When converting the GFR from body weight to body surface area, the reference range (40-60 ml min(-1) m(-2) ) in the latter was much more stable than that (6-11 ml min(-1) kg(-1) ) in the former. For nephropathy rats induced by cisplatin (3.75-7.5 mg kg(-1) , i.v., single dose), bromoethylamine hydrobromide (BEA, 250-500 mg kg(-1) , i.v., single dose) or puromycin aminonucleoside (PAN, 15 mg kg(-1) day(-1) , s.c., 10 days), GFR decreased or tended to decrease before increasing in serum urea nitrogen (UN) and creatinine concentrations. Accordingly, serum UN and creatinine concentrations became elevated when the GFR decreased to 50-60% of the basal value. This method without urine collection contributes to the reduction of animal numbers because of repeated application to the same animals.
Journal of Applied Toxicology 01/2011; 31(4):360-5. · 2.48 Impact Factor
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ABSTRACT: To establish a simple procedure for estimating the glomerular filtration rate (GFR) in conscious rabbits, we used the conventional multisample approach to develop a single-blood-sample method. A bolus injection of inulin was administered intravenously at a dose of 40 mg/kg to male New Zealand White rabbits, and blood was collected 30, 60, 90, and 120 min later. Serum inulin, urea nitrogen, and creatinine concentrations were determined. Using this multi-sample method, the reference GFR in clinically healthy rabbits was 4.01 ± 0.17 mL/min/kg (n = 17). In rabbits given an intravenous injection of the antitumor agent cisplatin, GFR fell before serum urea nitrogen and creatinine concentrations increased. Based on cumulative GFR data from healthy and nephropathy rabbits, the GFR obtained from the 3-sample method (30-, 60-, and 90-min samples) was closely correlated (r = 0.99) with that calculated from the estimated distribution volume and serum inulin concentration at 90 min after inulin injection in the single-blood-sample method. These results demonstrate that the single-blood-sample method supports sequential GFR measurements in rabbits and is a versatile procedure not only for research purposes but also in clinical settings.
Journal of the American Association for Laboratory Animal Science: JAALAS 01/2011; 50(5):702-7. · 0.71 Impact Factor
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ABSTRACT: The present study evaluated the effects of calcitriol dissolved in an oleaginous vehicle (calcitriol-OLE) on changes in plasma calcitriol, calcium and bone metabolic markers in nonpregnant, nonlactating Holstein cows. Five cows were treated intramuscularly or subcutaneously with calcitriol-OLE and oleaginous vehicle alone using a 5 × 5 Latin square design. Additionally, cows were also treated intravenously with calcitriol dissolved in an aqueous vehicle (calcitriol-AQU) for comparison. The plasma calcitriol concentrations after intramuscular and subcutaneous calcitriol-OLE administrations peaked at 24 and 12 hr, respectively, remained significantly elevated until day 3, returned to the respective control levels on day 5 and decreased significantly on day 7. In cows given intravenous calcitriol-AQU, the calcitriol levels decreased with linearity on day 1. The plasma calcium levels rose from 12 hr post-dose and peaked on day 2 for both preparations and in all three administration routes. Significantly increased calcium levels continued until day 5 in the intramuscular and intravenous routes and day 7 in the subcutaneous route. The plasma osteocalcin concentrations significantly increased from day 3 for calcitriol-OLE and from day 5 for calcitriol-AQU, whereas the bone resorption markers, tartrate-resistant acid phosphatase isoform 5b and hydroxyproline, decreased during this time. These results suggest that either intramuscular or subcutaneous injection of calcitriol-OLE extends and maintains supraphysiological calcitriol levels in the plasma and prolongs hypercalcemia. Moreover, exogenous calcitriol in normocalcemic cows increases the plasma osteocalcin concentration and decreases the plasma levels of bone resorption markers probably due to hypercalcemia.
Journal of Veterinary Medical Science 09/2010; 73(2):185-91. · 0.85 Impact Factor
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ABSTRACT: We examined fluctuations in plasma tartrate-resistant acid phosphatase isoform 5b (TRAP5b) measured using fluorometry in conjunction with those in calcium (Ca) and other bone metabolic markers from 2 weeks prepartum to 2 weeks postpartum in 7 primiparous and 18 multiparous pregnant cows. The plasma Ca concentration decreased temporarily on the day of calving in multiparous cows only. Plasma TRAP5b peaked on the day of calving in primiparous and multiparous cows and was significantly lower in multiparous cows than in primiparous cows 2 weeks before and after parturition. Plasma hydroxyproline increased 1 week postpartum in multiparous cows. Bone-specific alkaline phosphatase and osteocalcin tended to decrease after parturition in primiparous and multiparous cows. These results suggest that bone resorption increases around parturition in healthy parturient cows from the viewpoint of the TRAP5b activity.
Journal of Veterinary Medical Science 06/2010; 72(6):773-6. · 0.85 Impact Factor
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ABSTRACT: To ascertain the clinicopathological process underlying dysglycemia induced by the fluoroquinolone antibacterial gatifloxacin (GFLX), we orally administered 100 or 300 mg/kg/day to male clinically healthy (naive) or spontaneous type II (diabetic) Goto-Kakizaki rats for 15 days (days 1 to 15). Treatment of naive rats with GFLX led to decreased blood glucose concentrations at 100 mg/kg/day on day 1. In diabetic animals, markedly increased blood glucose concentrations were noted from 100 mg/kg/day on day 3, and all of the animals given 300 mg/kg/day died or were killed because of moribund conditions by day 9. In a glucose tolerance test, serum insulin concentrations decreased significantly in naive rats receiving 300 mg/kg/day. Microscopically, cytoplasmic vacuolations of the pancreatic islets were observed in naive rats receiving 300 mg/kg/day, and congestion and/or hemorrhage were additionally noted in diabetic rats given 100 mg/kg/day or more. In toxicokinetics with 100 mg/kg/day, AUC(0-8 hr) values for GFLX were higher in diabetic rats than in naive rats, and relatively high serum GFLX concentrations at 8 hr post-dose and extraordinarily high pancreatic GFLX concentrations were also observed in diabetic rats. These results demonstrate that hypoglycemia or hyperglycemia induced by GFLX is associated with higher distribution and retention of GFLX in the pancreas, leading to disturbed insulin secretion.
Journal of Veterinary Medical Science 05/2010; 72(5):567-73. · 0.85 Impact Factor
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ABSTRACT: This study determined the appropriate biochemical assay for measuring plasma tartrate-resistant acid phosphatase isoform 5b (TRAP5b) activity; this information is important to clarify the relationship between plasma TRAP5b and known biochemical bone markers in cattle. When plasma TRAP5b was measured using fluorometric and spectrophotometric methods, hemolysis products in plasma did not affect the former method. In plasma from healthy cattle, there was a good correlation (r=0.66) between the 2 methods. In age-related profiles, plasma TRAP5b (r=-0.53), hydroxyproline (HYP, r=-0.56) and bone-specific alkaline phosphatase (BALP, r=-0.44) showed significant negative correlations with age; these three parameters decreased until 4 or 5 years of age and then remained constant. There were significant correlations between TRAP5b and HYP (r=0.83) or BALP (r=0.83). Our results show that the fluorometric assay can be performed with a high degree of precision and reproducibility without interference from hemolysis, and that the age-related changes in plasma TRAP5b, HYP, and BALP constitute additional background values for clinical guidance in bovine medicine.
Journal of Veterinary Medical Science 12/2009; 71(12):1637-42. · 0.85 Impact Factor
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ABSTRACT: To establish a simple and convenient procedure for the determination of glomerular filtration rate (GFR) in conscious rats, we developed a single-blood-sample method, in contrast to the conventional three-sample method, using a bolus injection of the nonionic contrast medium iodixanol.
Iodixanol was intravenously administered at 1500 mg I/kg to healthy or renal-impaired rats, and blood was collected 60, 120, and 180 min later. Serum iodixanol concentrations were measured by HPLC, and serum urea nitrogen (UN) and creatinine concentrations were determined as renal function tests.
In rats subjected to 1/2 and 3/4 nephrectomies, GFR values decreased significantly without and with increases in serum UN and creatinine concentrations, respectively. In rats treated subcutaneously with gentamicin sulfate (GM) at 80 mg/kg/day or puromycin aminonucleoside (PAN) at 15 mg/kg/day for 10 consecutive days, the GFR values decreased or showed a tendency to decrease before increases in serum UN and creatinine concentrations. Accordingly, when the GFR decreased to more than 60% of the basal value, serum UN or creatinine concentrations became elevated. The GFR values obtained from the three-sample method were closely correlated (r=0.83) with those calculated from the estimated distribution volume (V) and serum iodixanol concentration 120 min after iodixanol injection in the single-blood-sample method in which serum iodixanol concentrations ranged between 20 and 250 microg I/mL.
These results suggest that the single-blood-sample method with a bolus injection of iodixanol, allowing for the repeated use of the same animals, is an expedient procedure without ensuring accurate urine collection.
Journal of pharmacological and toxicological methods 10/2009; 61(1):59-64. · 2.32 Impact Factor
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ABSTRACT: To better understand the neurotoxicity caused by the pyrethroid pesticide, we examined the effects of the N-methyl-D-aspartate (NMDA) receptor antagonists MK-801, a non-competitive cation channel blocker, and 2-amino-5-phosphonovaleric acid (APV), a competitive Na(+) channel blocker, on extracellular dopamine levels in male Sprague-Dawley rats receiving the type II pyrethroid deltamethrin using an in vivo microdialysis system. Deltamethrin (60 mg/kg, i.p.) evidently increased striatal dopamine levels with a peak time of 120 min, and the local infusion (i.c.) of either MK-801(650 muM) or APV (500 muM) completely blocked these actions. The fluctuation in the dopamine metabolite 3-MT also resembled that in dopamine. Our results suggest that dopamine-releasing neurons would be modulated via the NMDA receptor by the excitatory glutamatergic neurons after deltamethrin treatment.
Journal of Veterinary Medical Science 09/2009; 71(8):1129-32. · 0.85 Impact Factor
