Our study aimed at elucidating the effects of acute central hypervolemia induced by water immersion (WI) on renal hemodynamics, hormonal responses and on cardiovascular control in @entity101 @entity1 , as well as at evaluating the possible role of the opioidergic system (OS) in determining these effects. Thirteen essential @entity101 were studied for 2 h before and for 2 h during WI. This was done twice, without and with i.v. injection of the OS antagonist @entity1510 . Before and during WI alone, glomerular filtration rate (GFR), effective renal plasma flow (ERPF), renal vascular resistance (RVR), mean arterial pressure (MAP), pulse interval (PI), spontaneous baroreflex sensitivity ( @entity4375 ), Low frequency to High frequency (LF/HF) ratio in PI spectra, hematocrit, urinary @entity1372 excretion, plasma renin activity (PRA) and @entity1369 (PA) were assessed. Based on their response to WI, @entity101 were subdivided into two groups: ERPF+ (n = 7) in whom WI increased ERPF, and ERPF- (n = 6) in whom WI reduced ERPF. ERPF+ displayed a higher @entity4375 than ERPF- at baseline and during WI. A suppression of PRA and PA and an increase in MAP and urinary @entity1372 excretion were found in both groups. In ERPF+ @entity1510 caused RVR and MAP to increase during WI and this response was associated with a blockade of the increase in ERPF in this group, while @entity4375 and natriuresis were unchanged. In ERPF- @entity1510 did not affect WI-induced MAP, ERPF, RVR and @entity4375 changes, while it blunted @entity1372 excretion. Our data provide the first evidence of a differentiate renal hemodynamic response to WI in @entity101 ; they also suggest that while OS may significantly potentiate the renal vasodilatory response to WI in ERPF+, it does not affect the natriuretic response nor the changes in systemic cardiovascular regulation induced by central hypervolemia.

Renal and cardiovascular responses to water immersion in essential XXXX : is there a role for the opioidergic system?

@entity1 :: ('9606', 'Species') :: ['patients'] @entity1369 :: ('MESH:D000450', 'Chemical') :: ['aldosterone'] @entity101 :: ('MESH:D006973', 'Disease') :: ['hypertensives', 'hypertension', 'hypertensive'] @entity1372 :: ('MESH:D012964', 'Chemical') :: ['sodium'] @entity4375 :: ('11246', 'Species') :: ['BRS'] @entity1510 :: ('MESH:D009270', 'Chemical') :: ['naloxone']
@entity101 :: (MESH:D006973,Disease) :: ['hypertension']
