Vascular Resistance in the Isolated Gills of Octopus macropus and Nautilus pompilius

Abstract

The gills of cephalopods represent a potential site of regulation of vascular peripheral resistance. Measurements of pressure-flow relationships in the isolated gills of Octopus macropus and Nautilus pompilius gave no evidence of autoregulation. Perfusion with putative neurotransmitters showed 5-hydroxytryptamine, and possibly dopamine, to reduce vascular resistance. Physiological concentrations of acetylcholine and noradrenaline did not alter resistance to flow.