The endothelin (ET)-B receptor subtype is expressed on vascular endothelial and smooth muscle cells and participates in vasodilatation and vasoconstriction. Controversy exists regarding the role of the @entity48930 receptor as a mediator of systemic, pulmonary, and renal vasoconstriction in states of marked @entity11976 activation. Moreover, the potential activation of endogenous @entity11976 with secondary stimulation of the @entity11977 receptor in response to sarafotoxin S6c (S6c) remains unclear. This study was designed to assess the cardiovascular actions of @entity48930 activation with S6c in the presence and absence of selective @entity11977 antagonism with @entity13073 and dual @entity11977 / @entity48930 antagonism with @entity45353 in the anesthetized @entity235 . Compared with time control (n = 5), S6c increased from baseline systemic vascular resistance (SVR) [28 +/- 7 vs. 14 +/- 3 resistance units (RU), P < 0.05] and pulmonary vascular resistance (PVR) (3.2 +/- 0.7 vs. 0.9 +/- 0.3 RU, P < 0.05) and @entity998 (CO) (-1.7 +/- 0.3 vs. -0.5 +/- 0.1 l/min, P < 0.05), with no differences in renal vascular resistance in association with increases in plasma @entity11976 . S6c also decreased mixed venous @entity26 saturation (SVO2) (56 +/- 6 vs. 76 +/- 5%, P < 0.05). Selective @entity11977 receptor antagonism did not affect the actions of S6c, with the exception that @entity11977 receptor antagonism blocked the increase in SVR to high-dose S6c. Dual @entity11977 / @entity48930 receptor antagonism attenuated the increase from baseline in SVR (7 +/- 1 vs. 28 +/- 7 RU, P < 0.05) and PVR (0.7 +/- 0.2 vs. 3.2 +/- 0.7 RU, P < 0.05) and decrease from baseline in CO (-0.9 +/- 0.1 vs. -1.7 +/- 0.3 l/min, P < 0.05) and SVO2 (-7 +/- 3 vs. -20 +/- 3%, P < 0.05) observed with S6c alone. In summary, this study demonstrates an important role of @entity48930 receptor activation in vivo, which results in increases in plasma @entity11976 and systemic and pulmonary vasoconstriction and reductions in CO and SVO2. This study also supports a modest role for the @entity11977 receptor in mediating the systemic vasoconstrictor response to high-dose S6c.

Cardiovascular actions of XXXX activation in vivo and modulation by receptor antagonism.

@entity11977 :: ('450187(Tax:9615)', 'Gene') :: ['ET-A'] @entity13073 :: ('MESH:C079574', 'Chemical') :: ['FR-139317'] @entity11976 :: ('403424(Tax:9615)', 'Gene') :: ['ET-1'] @entity48930 :: ('403862(Tax:9615)', 'Gene') :: ['ET-B'] @entity45353 :: ('MESH:C087551', 'Chemical') :: ['SB-209670'] @entity235 :: ('9615', 'Species') :: ['dog'] @entity998 :: ('MESH:D002303', 'Disease') :: ['decreased cardiac output'] @entity26 :: ('MESH:D010100', 'Chemical') :: ['oxygen']
@entity48930 :: (403862(Tax:9615),Gene) :: ['ET-B']
