ASSAY OF ANTIDIURETIC SUBSTANCE IN PLASMA OF NORMAL AND DIABETES INSIPIDUS DOGS1

Abstract
Alcohol anesthetized rats constitute a satisfactory and sensitive test for circulating antidiuretic substance in dog plasma. Normal dog plasma contains circulating antidiuretic activity which ranges from 45 to 105 microunit equivalents of vasopressin with a mean of 80 microunit equivalents per cc. Plasma from diabetes insipidus dogs maintained in this condition for a year and a half does not contain any detectable antidiuretic activity.