Platelet and plasma vasopressin in dog during hydration and vasopressin infusion.
Dog platelets contain a substance immunologically similar to arginine vasopressin. In conscious and anesthetized dogs under basal conditions, platelet immunoreactive vasopressin accounts for approximately 40% of the total circulating immunoreactive vasopressin. When the plasma vasopressin concentration in the anesthetized dog was lowered 75% by intravenous infusion of isotonic dextrose solution for 2 h, the platelets failed to discharge a significant quantity of immunoreactive vasopressin. Subsequently, when the plasma vasopressin concentration was elevated to a level 10-fold greater than the initial levels by intravenous infusion of arginine vasopressin, there was no statistically significant increase in the estimated platelet vasopressin content measured 1 and 2 h after the start of the infusion, although there was the suggestion that the platelets had indeed taken up some vasopressin after 2 h of vasopressin infusion. Thus immunoreactive vasopressin in dog platelets does not appear to exchange readily with plasma vasopressin. The physiological role of platelet immunoreactive vasopressin remains to be determined.
D000818:Animals; D001127:Arginine Vasopressin / Q000008:administration & dosage / Q000494:pharmacology*; D001792:Blood Platelets / Q000378:metabolism*; D004285:Dogs; D006863:Hydrogen-Ion Concentration; D007263:Infusions, Parenteral; D007700:Kinetics; D011863:Radioimmunoassay; D014667:Vasopressins / Q000097:blood*
D014667:Vasopressins; D001127:Arginine Vasopressin