Oxytocin and renal function in the rat; an investigation of a possible proximal site of action.
Direct measurements of proximal tubular fluid reabsorption have been employed to examine the possible renal site of action of oxytocin. In whole kidney studies the natriuresis and chloriuresis, which occurred during the period of oxytocin infusion, did not coincide with the associated diuresis. The latter reached a peak 10-20 min after hormone administration has ceased. The separation in the saliuretic and diuretic responses underlines the apparent independence of these actions of oxytocin on the renal handling of water and electrolytes. The disturbances in renal function were not related to any change in glomerular filtration rate (gfr) and an examination of single nephron function failed to detect any significant effect of oxytocin on proximal tubular reabsorption. The renal actions of oxytocin would therefore appear to emanate from altered tubular rather than glomerular function, though the present study provides no support for a proximal site of action.
D000818:Animals; D001834:Body Water / Q000378:metabolism; D004573:Electrolytes / Q000652:urine; D005919:Glomerular Filtration Rate / Q000187:drug effects; D007687:Kidney Tubules, Proximal / Q000378:metabolism*; D008297:Male; D009318:Natriuresis / Q000187:drug effects; D009399:Nephrons / Q000378:metabolism; D010121:Oxytocin / Q000494:pharmacology*; D010477:Perfusion; D051381:Rats; D011919:Rats, Inbred Strains; D012965:Sodium Chloride / Q000652:urine; D014882:Water-Electrolyte Balance / Q000187:drug effects
D004573:Electrolytes; D012965:Sodium Chloride; D010121:Oxytocin