Pulmonary vasoregulation by arginine vasopressin in conscious, halothane-anesthetized, and pentobarbital-anesthetized dogs with increased vasomotor tone.

Abstract

Arginine vasopressin (AVP) is an important "stress" hormone that is known to play a key role in cardiovascular homeostasis of the systemic circulation. In contrast, the effects of AVP on the pulmonary circulation have not been extensively investigated, and the extent to which general anesthesia alters the pulmonary vascular response to AVP is entirely unknown. Our first objective was to assess the effects of AVP on the pulmonary vascular pressure-flow relation in chronically instrumented conscious dogs in the setting of an acute elevation in pulmonary vasomotor tone. Our second objective was to investigate the effects of halothane and pentobarbital anesthesia on the pulmonary vascular response to AVP after inducing the same degree of pulmonary preconstriction achieved in the conscious state.