EFFECT OF LYOPHILIZED PLASMA AND PLASMA FRACTIONS FROM HYPOPHYSEAL-PORTAL VESSEL BLOOD ON ADRENAL ASCORBIC ACID1

Abstract

Hydrocortisone-inhibited, intact rats injected with an amount of lyophilized hypothalamico-hypophy-seal portal vessel plasma equivalent to 10 ml of whole plasma showed a decrease of -107 [plus or minus] 12.9 mg of ascorbic acid per 100 g adrenal tissue. Similarly treated intact rats receiving an equivalent amount of lyophilized carotid artery plasma or hypophysectomized rats receiving an equivalent amount of lyophilized portal vessel plasma showed decreases of only 0 [plus or minus] 2.8 and -14 [plus or minus] 5.4, respectively. The substance in portal plasma responsible for this ascorbic acid reduction is non-dialyzable and following low temperature alcohol fractionation of the plasma proteins is found to be present in a single fraction. Similar activity was present in commercial Pitressin (beta-hypophamine) as previously observed. Results indicate the active substance is either a large protein molecule or is bound to a large protein and is probably not identical with vasopressin.