THE ATRIAL RECEPTORS RESPONSIBLE FOR THE DECREASE IN PLASMA VASOPRESSIN CAUSED BY DISTENSION OF THE LEFT ATRIUM IN THE DOG

• Published in: Experimental physiology 1984-01, Vol.69 (1), p.73-81
• Main Authors: Bennett, K. L., Linden, R. J., Mary, D. A. S. G.
• Format: Article
• Language: English
• Subjects: Afferent Pathways - physiology; Animals; Biological and medical sciences; Cold Temperature; Dogs; Fundamental and applied biological sciences. Psychology; Heart Atria - innervation; Lymphatic system; Nerve Fibers - physiology; Pressoreceptors - physiology; Reflex - physiology; Vagus Nerve - physiology; Vasopressins - blood; Vertebrates: cardiovascular system
• ISSN: 0958-0670; 0144-8757; 1469-445X
• DOI: 10.1113/expphysiol.1984.sp002797

In dogs anaesthetized with chloralose, the effects of cooling the cervical vagi on the reflex decrease in plasma concentration of vasopressin, caused by distension of a large balloon in the lumen of the left atrium, were examined. Distension of the balloon in ten dogs with the vagi at 37°C resulted in a decrease in plasma concentration of vasopressin and, as before, an increase in urine flow. The responses were not significantly affected by cooling to 16·18 °C but were abolished at 9 °C. At 16-18 °C the increase in activity in myelinated vagal afferent fibres is largely unchanged and at 9 °C is abolished (Kappagoda, Linden & Sivananthan, 1979; Sivananthan, Kappagoda & Linden, 1981). It is concluded that the decrease in plasma concentration of vasopressin during distension of the left atrium is mediated by the Paintal-type atrial receptors with myelinated vagal afferent fibres.