The Contribution of Vascular Receptors to +Gz Tolerance

Abstract : The feasibility of employing instrumental, restrained, conscious dogs in acceleration studies on the centrifuge has been demonstrated. The leads from implanted sensors pass through the skin on the upper back and when not connected to signal conditioning equipment are placed in a pocket of a nylon jacket worn by the dog. Protection of the sensor leads, in addition to the jacket, is afforded by an inflated rubber tube placed about the dog's neck. Measurements of carotid artery flow, vena caval flow and aortic pressure have been obtained during experimental sequences. The investigators felt that the primary effect of denervation was attenuation of peripheral resistance to rapid onset acceleration necessitating significantly higher heart rates and cardiac outputs for a given carotid flow and eye level blood pressure. (Author)