Presence of Antidiuretic Material in Blood of Hypophysectomized Rats

Abstract
Antidiuretic activity was found in the blood of 21 of 29 rats hypophysectomized for 1 month or more, in amts. similar to those found in normal animals. No antidiuretic material was found in the blood of recently hypophysectomized animals. The hypothalami of the 30-day postoperative animals contained activity equivalent to about 5 milliunits of vassopressin. The hypothalami of recently operated animals had much less activity.