Studies in avian adrenal steroid function: I: Survival and mineral balance following adrenalectomy in domestic ducks ( Anas platyrhynchos L.)

Abstract

Surgically adrenalectomised ducks survive 117 ± 17 hr ( n = 8), withouth NaCl or steroid therapy. Na + and K + metabolism were studied in chronically restrained adrenalectomised or sham-operated birds for up to 5 days following surgery: sham-operated birds remained in Na + balance by matching renal-cloacal Na + retention to intake rates, but during the first 2–3 postoperative days adrenalectomised birds were unable to reduce cloacal fluid Na + concentrations. The resultant natriuresis (despite reduced cloacal fluid flow rates) and the low feeding rate brought adrenalectomised birds into severely negative Na + balance. All birds showed negative K + balance initially after surgery. 3–5 Days after adrenalectomy, birds recovered normal Na + and K + balance in the absence of residual adrenal tissue, probably due to steroid-independent rectal ion transport. Normalised ion balances were at a high turnover rate in sham-operated birds, but at a low rate in adrenalectomised birds. However, the latter group showed persistent severe hyponatraemia and kyperkalaemia until death.