The Effects of Parasympathetic Nerve Stimulation on the Microcirculation and Secretion in the Nasal Mucosa of the Cat

Abstract

The effects of selective parasympathetic nerve activation on the secretory response and the vascular exchange and capacitance sections in the cat nasal mucosa were studied. The vascular events were investigated by measuring the local disappearance of 125I− and changes in gross pulse rate from 131I-labelled serum albumin as monitored over the nose. A frequency-dependent increase in nasal secretion and local blood content occurred in the range 0.5-12 imp/sec: an increase in disappearance rate was observed at the same time. This indicates that the vascular and secretory responses are activated simultaneously. The secretory responses, but not the vascular events, were shown to be blocked by atropine. Intra-arterial infusion of bradykinin caused an increase in the disappearance rate similar to that seen after parasympathetic nerve stimulation, whereas infusion of arachidonic acid or indomethacin had no effect. The results thus show that the postganglionic parasympathetic mediator of nasal secretion is choliner...