Regulation of Renal Aquaporins and Sodium Transporters During Vasopressin-Escape in the Rat
Several clinical conditions, e.g., congestive heart failure and cirrhosis are associated with inappropriately elevated vasopressin levels relative to serum osmolality (Bichet et al., 1992). In addition, ectopic production of vasopressin-like substances (usually by tumors) can produce inappropriate antidiuresis. This disorder is known as the Syndrome of Inappropriate Antidiuretic Hormone (vasopressin) secretion (SIADH). As expected, inappropriately elevated plasma vasopressin levels will often result in water retention and hyponatremia. Eventually patients go through a physiological process known as “vasopressin-escape” in which they begin to excrete a higher volume of more dilute urine, despite continually high levels of circulating vasopressin. This escape process helps to reduce water retention and more symptomatic hyponatremia. Until recently little was known about the molecular mechanisms underlying escape.
KeywordsPermeability Aldosterone Vasopressin Phosphodiesterase Thiazide
Unable to display preview. Download preview PDF.
- Bichet DG Kluge R Howard RL and Schrier RW 1992 Hyponatremic states In The Kidney: Physiology and Pathophysiology (D W Seldin and G Giebisch eds) Raven New York p 1727–1751Google Scholar
- Ecelbarger CA Chou C-L Lee AJ DiGiovanni SR Verbalis JG and Knepper MA 1998 Escape from vasopressin-induced antidiuresis: role of vasopressin resistance of the collecting duct Am J Physiol 214: Fl 161-F1166Google Scholar
- Ecelbarger CA Verbalis JG and Knepper MA 1999 Rapid up-regulation of thiazide-sensitive cotransporter and α-ENaC expression in a rat model of vasopressin escape [Abstract] J Am Soc Nephrol 10: 14AGoogle Scholar
- Murase T Baker EA Tian Y Knepper MA and Verbalis JG 1998 Down-regulation of kidney AVP V2 receptor expression during renal escape from vasopressin-induced antidiuresis [Abstract] J Am Soc Nephrol 9: 23AGoogle Scholar
- Nielsen S DiGiovanni SR Christensen EI Knepper MA and Harris HW 1993 Cellular and subcellular immunolocalization of vasopressin-regulated water channel in rat kidney Proc Natl Acad SciUSA 90: 166311667Google Scholar