Diet-induced @entity28 (DIO) attenuates the arterial cardiac baroreceptor reflex, but the mechanisms and sites of action are unknown. This study tested the hypothesis that @entity19553 impairs central aortic baroreceptor pathways. Normal chow control (CON) and high-fat-chow @entity28 -resistant (OR) and @entity28 -prone (OP) @entity35 were anesthetized (inactin, 120 mg/kg) and underwent sinoaortic denervation. The central end of the aortic @entity9598 nerve (ADN) was electrically stimulated to generate frequency-dependent baroreflex curves (5-100 Hz) during selective activation of myelinated (A-fiber) or combined (A- and @entity7183 ) ADN baroreceptors. A mild stimulus (1 V) that activates only A-fiber ADN baroreceptors induced robust, frequency-dependent @entity9598 and bradycardic responses in CON and OR @entity35 , but these responses were completely abolished in OP @entity35 . Maximal activation of A fibers (3 V) elicited frequency-dependent reflexes in all groups, but a @entity51 was still present in OP @entity35 . Activation of all ADN baroreceptors (20 V) evoked even larger reflex responses. Depressor responses were nearly identical among groups, but OP @entity35 still exhibited attenuated @entity1168 . In separate groups of @entity35 , the reduced heart rate (HR) response to maximal activation of ADN A fibers (3 V) persisted in OP @entity35 following pharmacological blockade of b(1)-adrenergic or muscarinic receptors, suggesting @entity4148 (PNS) and sympathetic nervous system (SNS) reflex pathways. However, the bradycardic responses to direct efferent vagal stimulation were similar among groups. Taken together, our data suggest that DIO severely impairs the central processing of myelinated aortic baroreceptor control of HR, including both PNS and SNS components.

Diet-induced XXXX severely impairs myelinated aortic baroreceptor reflex responses.

@entity19553 :: ('CHEBI:52032', 'Chemical') :: ['DIO'] @entity9598 :: ('MESH:C535349', 'Disease') :: ['depressor'] @entity28 :: ('MESH:D009765', 'Disease') :: ['obesity'] @entity7183 :: ('10185', 'Species') :: ['C-fiber'] @entity51 :: ('MESH:D009461', 'Disease') :: ['dramatic deficit'] @entity4148 :: ('MESH:D001342', 'Disease') :: ['deficits in both parasympathetic nervous system'] @entity35 :: ('10116', 'Species') :: ['rats'] @entity1168 :: ('MESH:D001919', 'Disease') :: ['bradycardia']
@entity28 :: (MESH:D009765,Disease) :: ['obesity']
