AJP - Renal Physiology, Vol 258, Issue 5 1211-F1217, Copyright © 1990 by American Physiological Society
Cyclooxygenase-dependent mediators of renal hemodynamic function in female rats
K. A. Munger and R. C. Blantz
Department of Medicine, Vanderbilt School of Medicine, Nashville, Tennessee 37232.
Previous studies have revealed a sex-dependent difference in response to
cyclooxygenase inhibition in anesthetized male and female rats. Female rats
have shown an unexpected vasodilation in response to prostaglandin (PG)
inhibition. The present studies were designed to further investigate the
sex-dependent role of the PG system in the control of normal renal
hemodynamics in female Munich-Wistar rats. Renal hemodynamic studies were
performed on anesthetized female rats before and during acute
cyclooxygenase inhibition using a variety of protocols. One group underwent
subacute unilateral renal denervation. A separate group was chronically
catheterized and plasma catecholamines were measured during the awake state
and then after anesthesia under the euvolemic protocol. Another group was
administered the angiotensin II blocker, saralasin, before and during
cyclooxygenase inhibition. In a final group, flow to the distal nephron was
interrupted via placement of a wax block into the late proximal tubule to
determine the role of distal nephron flow and tubuloglomerular feedback in
the glomerular response to cyclooxygenase inhibition. It was determined
that neither the wax block nor saralasin administration attenuated the
vasodilatory response observed in normal female rats due to cyclooxygenase
inhibition; however, subacute unilateral renal denervation completely
blocked the vasodilatory response to PG inhibition in these female
Munich-Wistar rats. Plasma catecholamines were found to be similar whether
awake or under anesthesia. These studies indicate the importance of the
adrenergic system in modulating PG production in the acutely anesthetized
intact female rat.
