EVALUATION OF HEMOSTATIC ACTIVITY OF DESAMINO-D-ARGININE VASOPRESSIN (DDAVP) IN UREMIC RATS

DDAVP, an analog of vasopressin, has been shown to have hemostatic act ivity. Although it has been used clinically to control bleeding, there have been very few attempts to characterize this agent in experimenta l animals. We describe a new animal model which is fast, reliable and inexpensive, and which may be used to screen novel analogs of the pept ide. Under sodium pentobarbital anesthesia, rats were bilaterally neph rectomized and implanted with indwelling intravenous cannulae. The nex t day they were re-anesthetized, a standardized cut was made in the ta il and the tail was allowed to bleed into warm isotonic saline (25ml). After 10 min., the tail was removed from the saline and the blood los s was measured either by laser nephelometry or by colorimetric analysi s. DDAVP was then injected intravenously and the rat was allowed to re st quietly for 30 min., after which time a second incision was made in the tail and blood loss again measured for 10 min. Unlike bleeding ti me which was highly variable, blood loss proved to be a reliable index of the hemostatic activity. Thus we were able to demonstrate that DDA VP reduced blood loss in the uremic rats, whereas it was without effec t in intact rats.