title: The influence of acute starvation on the cardiovascular responses to lower body subatmospheric pressure or to standing in man.
abstract: The cardiovascular responses to lower body subatmospheric pressure or to standing were measured in the same nine normal male subjects after a 12 h and after a 48 h fast. After the 48 h fast there was a significant reduction in diastolic blood pressure and forearm vascular resistance (relative to the values after a 12 h fast) when subjects were supine. During exposure to lower body subatmospheric pressure, subjects who had fasted for 48 h showed an inability to maintain systolic blood pressure, accompanied by an impairment of forearm vasoconstriction and an exaggerated tachycardia (relative to their responses after a 12 h fast). Similar disorders of cardiovascular homoeostasis were seen on standing. The results are consistent with an inhibition of sympathetic nervous activity after a 48 h fast, but other possibilities are discussed.
mesh_terms: D000328:Adult; D001274:Atmospheric Pressure; D006439:Hemodynamics; D006801:Humans; D008297:Male; D009638:Norepinephrine / Q000097:blood; D011187:Posture; D012018:Reflex / Q000502:physiology; D013217:Starvation / Q000503:physiopathology*; D013564:Sympathetic Nervous System / Q000503:physiopathology
chemical_list: D009638:Norepinephrine