Effect of morphine withdrawal on food and water intake, urine output and electrolyte excretion in the rat: participation of the renin-aldosterone-system in renal excretory changes.
Male Wistar rats received two i.p. injections of morphine-HCl, 2.5 mg/kg at 8.00 a.m. and 2.00 p.m. on the 1st day: the dose was doubled every other day to reach a total daily dose of 40 mg/kg on the 4th day. This schedule was maintained for 12 days. On day 16 the animals received the last injection of morphine, 20 mg/kg. One hour later (9.00 a.m.) six rats were decapitated and PRA, PAC and ACTH were measured by radioimmunoassay. Groups of six rats were killed at 9.00 a.m. on the 1st, 2nd, 5th and the 8th day after morphine withdrawal. Control data for PRA, PAC and ACTH were obtained from eighteen saline-injected rats. Nine out of morphine-treated animals were kept in metabolism cages to investigate simultaneously food and water intake. and renal excretion. Morphine withdrawal after chronic morphine treatment in the rat resulted in antidiuresis and a reduction of electrolyte excretion which were not due to a reduction in water and food intake. The simultaneous increase of PRA and PAC associated with decreased electrolyte excretion indicates that, in addition to antidiuretic hormone, also the renin-aldosterone-system probably play a relevant role in the renal excretory changes after morphine withdrawal.
D000324:Adrenocorticotropic Hormone / Q000097:blood; D000450:Aldosterone / Q000097:blood; D000818:Animals; D004326:Drinking; D004435:Eating; D004573:Electrolytes / Q000652:urine; D006801:Humans; D007668:Kidney / Q000378:metabolism*; D008297:Male; D009020:Morphine / Q000633:toxicity*; D051381:Rats; D011919:Rats, Inbred Strains; D012083:Renin / Q000097:blood; D012084:Renin-Angiotensin System; D013375:Substance Withdrawal Syndrome / Q000378:metabolism*; D014554:Urination; D014882:Water-Electrolyte Balance
D004573:Electrolytes; D000450:Aldosterone; D009020:Morphine; D000324:Adrenocorticotropic Hormone; D012083:Renin