Effects of Propranolol on Reflex Vascular Responses
نویسنده
چکیده
To evaluate the role of ventricular baroreceptors in humans, we studied the effects of propranolol on reflex vasoconstrictor responses to simulated orthostatic stress. We measured forearm vascular resistance in 10 normal males in the control state and during lower body negative pressure (LBNP) at -10 and -40mm Hg before and after propranolol (0.1 mg/kg i.v.). Baseline forearm vascular resistance showed no significant change: 23.9 3.4 U (± SEM) before vs 28.0 ± 0.5 U after propranolol. Reflex increases in forearm vascular resistance during LBNP at -10 and 40 mm Hg were 5.2 ± 1.2 and 21.2 + 6.6 U before and 3.4 ± 1.2 and 10.6 ± 2.2 U, respectively, after propranolol. Thus, propranolol significant-
منابع مشابه
Effects of Propranolol
To evaluate the role of ventricular baroreceptors in humans, we studied the effects of propranolol on reflex vasoconstrictor responses to simulated orthostatic stress. We measured forearm vascular resistance in 10 normal males in the control state and during lower body negative pressure (LBNP) at -10 and -40mm Hg before and after propranolol (0.1 mg/kg i.v.). Baseline forearm vascular resistanc...
متن کاملCardiovascular responses in the sea raven, Hemitripterus americanus, elicited by vascular compression.
Increases in the water pressure (PW) around the trunk of the sea raven (Hemitripterus americanus Gmelin) were used to evaluate the effects of vascular compression on cardiovascular variables. Cardiac output (Vb), heart rate (fH) and blood pressures in the ventral aorta, dorsal aorta and ductus Cuvier (Pva, Pda and Pdc, respectively) were measured. A 20 cm H2O increase in PW decreased vascular c...
متن کاملStudies on the mechanism of pulmonary vascular responses to miliary pulmonary embolism.
The nature and mechanisms of pulmonary vascular responses which follow miliary pulmonary embolism were examined in intact dogs in which the isolated left lower lobe was perfused at constant blood flow. Embolization of the lung with plastic microspheres increased total pulmonary vascular resistance, whereas, in contrast, vascular resistance of the isolated perfused left lower lobe which was prot...
متن کاملSystemic circulatory responses to hypocapnia in man.
RICHAKDSON, DAVID Mr., HERMES A. KONTOS, A. JARRELL RAPER, AND JOHN L. PATTERSON, JR. Systemic circulatory responses to hypocapnia in man. Am. J. Physiol. !223(6): 1308-1312. 1972.Hypocapnic alkalosis, induced by voluntary hyperventilation in normal man, was associated with increases in cardiac output and in heart rate and decreases in mean arterial blood pressure and in systemic vascular resis...
متن کاملThe effects of propranolol on acute hypertension of anesthetized dogs and on the carotid sinus reflex responses of anesthetized and awake dogs.
Experiments are presented to show the effects of (1) propranolol on tbe response of systolic blood pressure and diastolic blood pressure to bilateral carotid artery occlusion in choralose-anesthetized dogs; (2) the effects of propranolol on acute hypertensive states in chloralose-anesthetized dogs; and (3) the effects of propranolol on the response of trained awake dogs to bilateral carotid art...
متن کامل