Effects of ADH on single-nephron glomerular filtration rates in the avian kidney.

BRAUN, ELDON J., AND WILLIAM H. DANTZLER. Effects of ADH on single-nephron glomerular Jiltration rates in the auian kidney. Am. J. Physiol. 226( 1) : 1-8. 1974.-Effects of ADH (arginine vasotocin) on the total-kidney glomerular filtration rate (GFR) and on single-nephron glomerular filtration rates (SNGFR) of reptilian-type (RT) and mammalian-type (MT) nephrons were studied in desert quail, Lophortyx gambelii. Low, probably physiological, doses (10 and 50 rig/kg) of arginine vasotocin (AVT) had no effect on mean arterial blood pressure, but caused reduction in total-kidney GFR primarily as a result of the decrease in the number of filtering RT nephrons. High, probably pharmacological, doses (200 rig/kg) of AVT produced increases, decreases, or biphasic changes in mean arterial blood pressure. With decreases or biphasic changes in mean arterial blood pressure, total-kidney GFR, SNGFR of MT nephrons, and the number of filtering RT nephrons decreased. With increases in mean arterial pressure, total-kidney GFR decreased, SNGFR of MT nephrons increased, and RT nephrons ceased filtering. The possible changes in intrarenal blood flow responsible for these effects on SNGFR, the possible relationship of effects of AVT and salt load on SNGFR, and the possible relationship of changes in the number of filtering RT nephrons to concentrating ability are discussed.