@entity1809 ) receptors are present in areas of the brain controlling autonomic nervous activity and the @entity2339 , including @entity3318 cells in the hypothalamic paraventricular nucleus (PVN). To determine whether brain @entity1809 receptors are involved in the activation of the @entity2339 and sympathetic system during stress, we studied the effects of acute immobilization stress on plasma @entity2661 , ACTH and @entity2819 , and mRNA levels of @entity3318 and @entity3318 receptors ( @entity3318 -R) in the PVN in @entity35 under central @entity1809 receptor blockade by the selective antagonist, @entity9886 . While basal levels of @entity1425 , @entity1063 and @entity935 in plasma were unaffected 30 min after i.c.v. injection of @entity9886 (10 microg), the increases after 5 and 20 min stress were blunted in @entity9886 treated @entity35 (P < 0.05 for @entity1063 , and P < 0.01 for @entity1425 and @entity935 , vs controls). Basal or stress-stimulated plasma ACTH and @entity2819 levels were unaffected by i.c.v. @entity9886 treatment. Using in situ hybridization studies, basal levels of @entity3318 mRNA and @entity3318 -R mRNA in the PVN were unchanged after i.c.v. @entity9886 . While @entity9886 had no effect on the increases in @entity3318 -R mRNA levels 2 or 3 h after 1 h immobilization, it prevented the increases in @entity3318 mRNA. The blunted plasma @entity2922 responses after central @entity1809 receptor blockade indicate that endogenous @entity1808 in the brain is required for sympathoadrenal activation during immobilization stress. While @entity1808 appears not to be involved in the acute secretory response of the @entity2339 , it may play a role in regulating @entity3318 expression in the PVN.

Brain XXXX modulates sympathoadrenal and hypothalamic pituitary adrenocortical activation during stress.

@entity935 :: ('MESH:D004298', 'Chemical') :: ['dopamine'] @entity1809 :: ('24180(Tax:10116)', 'Gene') :: ['AT1', 'Angiotensin II (Ang II) type-1 (AT1'] @entity1425 :: ('MESH:D004837', 'Chemical') :: ['epinephrine'] @entity1808 :: ('24179(Tax:10116)', 'Gene') :: ['Ang II'] @entity9886 :: ('MESH:D019808', 'Chemical') :: ['Losartan'] @entity2819 :: ('MESH:D003345', 'Chemical') :: ['corticosterone'] @entity2339 :: ('MESH:D007029', 'Disease') :: ['HPA axis', 'hypothalamic-pituitary-adrenal (HPA) axis'] @entity3318 :: ('81648(Tax:10116)', 'Gene') :: ['CRH'] @entity2922 :: ('CHEBI:33567', 'Chemical') :: ['catecholamine'] @entity35 :: ('10116', 'Species') :: ['rats'] @entity2661 :: ('MESH:D002395', 'Chemical') :: ['catecholamines'] @entity1063 :: ('MESH:D009638', 'Chemical') :: ['norepinephrine']
@entity1808 :: (24179(Tax:10116),Gene) :: ['angiotensin II']
