Endocrinology, Vol 103, 1009-1015, Copyright © 1978 by Endocrine Society

ARTICLES

Plasma neurophysin and vasopressin in the rat: response to adrenalectomy and steroid replacement

SM Seif, AG Robinson, EA Zimmerman and J Wilkins

Impaired excretion of a water load is known to occur in adrenal insufficiency and to be corrected by administration of glucocorticoid. Such impairment has been related to either a loss of a permissive effect of glucocorticoids on the diluting segments of the nephron or to an alteration of release, turnover, or action of antidiuretic hormone. Specific and sensitive RIAs for arginine vasopressin and neurophysin were utilized to measure plasma and pituitary levels of neurohypophyseal peptides at baseline and after an intragastrically administered water load. Conscious, unanesthetized, and nonstressed sham-operated, adrenalectomized, and adrenalectomized prednisone- treated rats were studied. The results demonstrate a significant elevation in vasopressin and neurophysin in plasma in adrenalectomized rats maintained in a normal state of hydration. After water loading, the adrenalectomized rats diluted their plasma osmolality but had a decreased urinary volume, increased urinary osmolality, and elevated vasopressin and neurophysin in their plasma. In the pituitary, vasopressin and neurophysin were depleted in adrenalectomized rats, indicating increased secretion of these peptides. It is concluded that elevated vasopressin in plasma may be an important factor in the incomplete water diuresis in adrenal insufficiency.

This article has been cited by other articles:

				T.-H. Kwon, J. Nielsen, S. Masilamani, H. Hager, M. A. Knepper, J. Frokiar, and S. Nielsen Regulation of collecting duct AQP3 expression: response to mineralocorticoid Am J Physiol Renal Physiol, December 1, 2002; 283(6): F1403 - F1421. [Abstract] [Full Text] [PDF]

				S.-e Ishikawa, T. Saito, A. Fukagawa, M. Higashiyama, T. Nakamura, I. Kusaka, S. Nagasaka, K. Honda, and T. Saito Close Association of Urinary Excretion of Aquaporin-2 with Appropriate and Inappropriate Arginine Vasopressin-Dependent Antidiuresis in Hyponatremia in Elderly Subjects J. Clin. Endocrinol. Metab., April 1, 2001; 86(4): 1665 - 1671. [Abstract] [Full Text]

				T. Saito, S.-E Ishikawa, F. Ando, M. Higashiyama, S. Nagasaka, S. Sasaki, and T. Saito Vasopressin-dependent upregulation of aquaporin-2 gene expression in glucocorticoid-deficient rats Am J Physiol Renal Physiol, September 1, 2000; 279(3): F502 - F508. [Abstract] [Full Text] [PDF]

				T. Saito, S.-e Ishikawa, F. Ando, N. Okada, T. Nakamura, I. Kusaka, M. Higashiyama, S. Nagasaka, and T. Saito Exaggerated Urinary Excretion of Aquaporin-2 in the Pathological State of Impaired Water Excretion Dependent upon Arginine Vasopressin J. Clin. Endocrinol. Metab., November 1, 1998; 83(11): 4034 - 4040. [Abstract] [Full Text]