1. To elucidate the functional consequence of endogenous phospholipase A2 activation, the effect of pretreatment with @entity3348 on @entity3044 , @entity1928 and @entity2710 inotropic responses in isolated @entity35 left atria was studied. 2. @entity3348 pretreatment resulted in a significant decrease of the positive inotropic response of @entity3044 , whereas no significant change in the @entity1928 response was seen. 3. A more prominent negative inotropic effect of @entity2710 could be perceived after @entity3348 pretreatment. These effects of @entity3348 were not simply reversed by @entity3543 , a phospholipase A2 inhibitor. 4. After combined @entity3543 / @entity3348 pretreatment, a positive inotropic response was elicited by @entity2710 , which could be blocked by @entity3897 but not by @entity1169 . 5. It is suggested that the combination of @entity3543 / @entity3348 abolishes the activity of an inhibitory G protein.

Effect of phospholipase A2 activation on the receptor function in the @entity35 left atrium: unmasking of a positive inotropic effect of XXXX .

@entity1169 :: ('MESH:D011433', 'Chemical') :: ['(+/-)-propranolol'] @entity3348 :: ('MESH:D008555', 'Chemical') :: ['Melittin', 'melittin'] @entity3044 :: ('MESH:D007545', 'Chemical') :: ['(-)-isoprenaline'] @entity3543 :: ('MESH:D011796', 'Chemical') :: ['mepacrine'] @entity3897 :: ('MESH:D001285', 'Chemical') :: ['atropine'] @entity35 :: ('10116', 'Species') :: ['rat'] @entity2710 :: ('MESH:D016210', 'Chemical') :: ['methacholine'] @entity1928 :: ('MESH:D005576', 'Chemical') :: ['forskolin']
@entity2710 :: (MESH:D016210,Chemical) :: ['methacholine']
