Reflex antidiuresis after occlusion of common carotid arteries in hydrated dogs

¹ Department of Physiology, University of North Carolina School of Medicine, Chapel Hill, North Carolina

Common carotid arteries were occluded bilaterally for 5 min below the thyrocarotid arterial junctions in mildly hydrated, anesthetized dogs. Within 5–15 min after the occlusion, urine flow declined and remained below control values for 30–105 min. Concurrently, the urine became hypertonic to systemic plasma and there was no evidence for renal vasoconstriction or increased solute reabsorption. The decrement in urine flow was accounted for entirely by the decline in free-water clearance. Prolonged periods of occlusion or increased hydration altered the response. Bilateral occlusion of the common carotid arteries for 5 min above intact thyrocarotid arterial junctions (but below the carotid sinuses) or below denervated thyrocarotid arterial junctions did not affect urine flow. The time course of the response, the characteristics of the urine, and the absence of renal vasoconstriction suggest that the procedure induced a reflex release of antidiuretic hormone. Furthermore, the data indicate that the receptor area for this reflex is located in the region of the junction of the common carotid and thyroid arteries.

Note:
With the Technical Assistance of Richard E. Bird