EFFECT OF ARGININE VASOTOCIN AND INDOMETHACIN ON THE RENAL FUNCTION IN HENS

Abstract

This chapter discusses the effect of arginine vasotocin (AVT) and indomethacin on the renal function in hens. AVT produced a clear antidiuretic response in unanesthetized hens. A dose of AVT −100 ng/kg body weight is about 4% of the amount of AVT stored in chicken neurohypophysis and corresponds more or less to the amount of AVT released to the blood after osmotic stimuli or hemorrhage. This dose is probably within the physiological range. The antidiuretic effect of AVT resulted primarily from a decrease in RBF and GFR. It is found that antidiuretic effect of AVT in the desert quail kidney may be a vascular action. AVT was found to cause intrarenal redistribution of blood flow by constriction of afferent arterioles of RT nephrons. It is shown that physiological doses of AVT produced a reduction in GFR, which results from a reduction in the number of filtering RT nephrons. Free-water clearance was increased following AVT administration. It is a result of a simultaneous increase of urine and plasma osmolality after AVT administration. The ratio of urine to plasma osmolality was in the control group 1.3 ± 0.1 and did not change after AVT administration.