[Changes in the kallikrein-kinin system of the blood following hypothalamo-hypophyseal stimulation of animals of different ages].

Changes occurring in the formation and synthesis of kinins become irregular with ageing: the content of kallikreinogenes decreases, the activity of kininase and inhibitors of trypsin falls, and total blood activity of hydrolysis of ethyl--N--benzoil--L--arginine ether rises. Stimulation of the hypothalamus causes an obvious activation of the kalikrein--kinin system in adult animals: the contents of kallikreinogenes and kininogenes fall, the kallikrein activity sharply increases, whereas the kininase activity decreases. Both single and repeated administrations of vasopressin induce the same shifts of kallikrein--kinin system as the stimulation of hypothalamus. On repeated administrations of vasopressin the kininase activity rises.