The urinary excretion of selenium in sheep treated with a vasopressin analogue.
The renal excretion of selenium was investigated in ewes with an excretion of hypotonic urine (control group) and in ewes with a formation of highly concentrated urine. Chronic stimulation of the urinary concentrating activity of sheep kidneys was induced by a long-term treatment with 1-desamino-8-D-arginine vasopressin (dDAVP), a synthetic analogue of vasopressin with prolonged effects. Young animals with 22 to 25 kg b.w. were fed a normal protein diet providing a daily intake of 129.25 g of crude protein, 12.03 MJ of digestible energy and 0.18 mg of selenium for 3 weeks. The vasopressin treated sheep (n = 11) were given subcutaneous injections of 12.5 micrograms of dDAVP in glycerol twice daily for one week before the clearance measurement of renal functions. The control group (n = 11) was treated with glycerol only. The administration of dDAVP resulted in a highly significant decrease of the urinary flow rate (from 3.19 +/- 0.50 in control group to 0.33 +/- 0.03 mL.min-1 in dDAVP animals, P < 0.001) without changes in the glomerular filtration rate (80.18 +/- 6.36 in controls vs. 77.86 +/- 6.26 mL.min-1, NS). No effects on plasma selenium level were observed (0.17 +/- 0.03 in controls vs. 0.20 +/- 0.03 mumol.L-1, NS) but the amounts of selenium excreted were found to be highly significantly reduced (from 0.29 +/- 0.05 in controls to 0.03 +/- 0.01 nmol.min-1, P < 0.001) in dDAVP treated sheep. Despite a large reduction in urinary flow rate, the selenium concentration in urine was actually the same in both groups (0.09 +/- 0.01 mumol.L-1) resulting in a sharp fall in the renal clearance of selenium (2.20 +/- 0.54 in controls vs. 0.18 +/- 0.03 mL.min-1, P < 0.01) due to dDAVP. This seems to be a consequence of the large increase in the selenium solvent drag induced by a vasopressin treatment. The results presented suggest that vasopressin may contribute to maintenance of the selenium balance in sheep via its effects on renal function.
Leng
L
L
Institute of Animal Physiology, Slovak Academy of Sciences, Kosice, Slovak Republic. lleng@saske.sk
Boldizárová
K
K
Faix
S
S
Kovác
G
G
D000818:Animals; D003894:Deamino Arginine Vasopressin / Q000494:pharmacology*; D004044:Dietary Proteins / Q000008:administration & dosage; D005260:Female; D005919:Glomerular Filtration Rate / Q000662:veterinary; D007668:Kidney / Q000187:drug effects* / Q000502:physiology; D012076:Renal Agents / Q000494:pharmacology*; D012643:Selenium / Q000378:metabolism / Q000652:urine*; D012756:Sheep / Q000378:metabolism* / Q000652:urine; D013997:Time Factors; D014882:Water-Electrolyte Balance / Q000187:drug effects
D004044:Dietary Proteins; D012076:Renal Agents; D003894:Deamino Arginine Vasopressin; D012643:Selenium