Flow of Blood to the Pineal Body of the Rat

Abstract

NUMEROUS cytological and histochemical observations indicate a secretory function for the pineal body of higher vertebrates^1,2. Physiologically also, the pineal body of the rat satisfies most of the criteria for an endocrine organ^3–5. Although anatomical evidence suggests that rat and mouse pineal vascularity is less than in some classical endocrine organs^6,7, in view of the relatively high blood flow rate to endocrine structures in general⁸, it is reasonable to expect the pineal to be similarly well perfused. We have found that the minimum rate of rat pineal blood flow per g exceeds that of most endocrine organs, equals that of the neurohypophysis and is surpassed only by that of the kidney.