Experimental water intoxication induced by dDAVP in rat, and its prevention with the vasopressin antagonist d(CH2)5Tyr(Et)VAVP.

A new rat model of the Schwartz--Bartter syndrome was created by the administration of 1-deamino-8-D-arginine vasopressin together with a forced water intake. The treatment led to water retention, hypernatriuria, marked hyponatraemia (in 4-5 days) and severe cerebral oedema. These changes could be prevented by the simultaneous administration of [1-(beta-mercapto-beta, beta-cyclopentamethylene-propionic acid)- 2-o-ethyltyrosine-4-valine] arginine vasopressin. The observations indicate that this vasopressin antagonist analogue might be of use in the future as an effective drug against the Schwartz--Bartter syndrome.