| Abstract |
The renal excretion of selenium was investigated in ewes with an excretion of hypotonicurine (control group) and in ewes with a formation of highly concentrated urine.Chronic stimulation of the urinary concentrating activity of sheep kidneys was inducedby a long-term treatment with 1-desamino-8-D-arginine vasopressin (dDAVP), a syntheticanalogue 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 vasopressintreated sheep () were given subcutaneous injections of 12.5 g of dDAVP inglycerol twice daily for one week before the clearance measurement of renal functions.The control group () was treated with glycerol only. The administration of dDAVPresulted in a highly significant decrease of the urinary flow rate (from 3.19 0.50 incontrol group to 0.33 0.03 mLmin in dDAVP animals, ) without changes in theglomerular filtration rate (80.18 6.36 in controls vs. 77.86 6.26 mLmin, NS). Noeffects on plasma selenium level were observed (0.17 0.03 in controls vs. 0.20 0.03molL, NS) but the amounts of selenium excreted were found to be highly significantlyreduced (from 0.29 0.05 in controls to 0.03 0.01 nmolmin, ) in dDAVPtreated sheep. Despite a large reduction in urinary flow rate, the selenium concentrationin urine was actually the same in both groups (0.09 0.01 molL) resulting in a sharpfall in the renal clearance of selenium (2.20 0.54 in controls vs. 0.18 0.03mLmin, ) due to dDAVP. This seems to be a consequence of the large increase inthe selenium solvent drag induced by a vasopressin treatment. The results presentedsuggest that vasopressin may contribute to maintenance of the selenium balance in sheep viaits effects on renal function. |
Vet.Res._0928-4249_2000_31_5/Vet.Res._0928-4249_2000_31_5_ART0005.pdf