Vasopressin Response to Water and Salt Load in Normal Cows

Abstract

Arginine vasopressin (AVP) or antidiuretic hormone plays a primary role in the regulation of the body fluids. Little is known at present about the regulation of AVP secretion in cattle. Our interest in the regulation of the release of AVP in cattle arises from two basic questions.

First, it has been demonstrated recently that administration of AVP to adult ruminants stimulates reticular groove contraction¹. This may be of interest, as suggested by others^1,2 for the oral administration of drugs that should bypass the ruminoreticulum. No data are available on the role of AVP in the consistent closure of the reticular groove in the young calf.

Secondly, pyloric stenos is in cattle results in a metabolic alkalosis. A dehydration occurs, accompanied by a hypochloraemia, a hypokalaemia, a metabolic alkalosis and a uraemia. An extreme dehydration can be found, with a production of diluted urine. No data are available of the plasma AVP concentrations in these cases.

To evaluate vasopressin values from patient cases and experimental animals, reference values were collected in 5 normal dairy cows during a water or a salt load.