Blood flow and secretion in the submaxillary gland of the rabbit during stimulation of the autonomic nerves.

Abstract

The excitation of the chorda-tympani nerve caused a marked increase in the blood flow through the gland and in secretion of saliva; both phenomena had a threshold frequency of around 0.3 Hz and reached a maximum at around 20 Hz, where a 6-fold increase in the blood flow and a salivary secretion of at the most 300 microliters/min were seen. Sympathetic excitation severely retarded the blood flow, which almost ceased at frequencies as low as 3-5 Hz; mostly single shocks of sympathetic stimulation reduced the blood flow through the gland. An on-going parasympathetic activation did not alter the effects of sympathetic stimulation on the blood flow and the parasympathetically produced salivary secretion almost stopped. The experiments support previous results, which have suggested electrical excitation of the sympathetic trunk at or above 2 Hz to cause a vasoconstriction which adversely affects the fluid secretion in the rabbit salivary glands.