Role of cardiac nerves in response to head-out water immersion in conscious XXXX .

@entity64 @entity1369 @entity235 @entity1372 @entity299 @entity1011 @entity1122 @entity6085
The circulatory, renal, and hormonal responses during 100 min of thermoneutral (37 degrees C) head-out water immersion (WI) were investigated in conscious intact (INT) and @entity299 ( @entity299 ) @entity235 . In the INT group, both left and right atrial and aortic transmural distending pressures and left ventricular contractile performance (LV dP/dtmax) increased, and total peripheral resistance remained unchanged. Cardiac output (QCO) increased in association with an increase in heart rate and LV dP/dtmax. Urine flow (V), @entity1372 excretion (UNaV), and osmolal clearance (Cosmol) all increased, whereas glomerular filtration rate, as indicated by @entity1011 clearance (CCr), remained constant. The diuresis and natriuresis occurred in the absence of any significant changes in plasma levels of @entity6085 ( @entity6085 ), @entity1369 , or plasma @entity1122 activity. The @entity299 animals showed a similar hemodynamic response except that the increase in QCO was now associated with an increase in @entity64 volume and no change in heart rate or LV dP/dtmax. Although the increase in V was similar in both magnitude and time course of the INT animals, there was no significant change in UNaV. Thus there is a striking change in the character of the response of the denervated group in that the natriuresis is abolished and, instead, a water diuresis occurred. Free water clearance increased, but no significant changes in Cosmol or CCr were observed. In addition plasma @entity6085 levels significantly declined during WI in the @entity299 group. These data indicate that cardiac receptors are important in determining the nature of the renal response to WI.
