The influence of varying the electrical frequency of sympathetic nerve stimulation on fluid and calcium secretion of the rat parotid salivary gland.

The effects of varying this frequency were studied in the absence and presence of the specific adrenergic antagonists. There were no appreciable differences in fluid and calcium secretion at different frequencies of stimulation when the nerve was stimulated alone or in the presence of the selective antagonists. Thus, it is difficult to differentiate between the effects of alpha- and beta-adrenergic receptor stimulation by varying the frequency of nerve stimulation. The findings also confirmed that both types of receptors are activated together when the sympathetic nerve is stimulated. beta-Adrenergic receptors play a major role in secretion of both fluid and Ca; alpha-adrenergic receptors seem to have a minor role in their regulation.