Intrinsic regulation of flow in an isolated tail preparation of the ocean pout (Macrozoarces americanus)

Abstract

Autoregulatory responses to changes in vascular transmural pressure (myogenic autoregulation) and to changes in pH and [Formula: see text] (metabolic autoregulation) were examined in an isolated tail preparation of the ocean pout (Macrozoarces americanus). Reducing perfusate [Formula: see text] had no effect on inflow. Inflow was, however, dependent on perfusate pH, vasoconstriction occurring with alkalosis, and vasodilation with acidosis. The finding that metabolic autoregulation occurred in response to pH and not [Formula: see text] may be related to the highly anaerobic nature of the white muscle mass found in the tail of the ocean pout. An increase in the external hydrostatic pressure which would produce vascular compression did not elicit compensatory myogenic autoregulation.