Effects of varying frequency of parasympathetic nerve stimulation on flow rate and ion concentrations of rat submandibular saliva.

Effects of adrenergic antagonists on chorda-evoked salivary secretion were studied. Flow rate, Ca and Na concentration of the chorda-evoked saliva were related to changes in frequency of stimulation of the chorda. Thus, as frequency of stimulation was increased, flow rate, Ca and Na concentrations increased. However, K concentration of nerve-evoked saliva was similar at all frequencies. Depletion of gland Ca concentration was also dependent on frequency of the stimulation; at the highest frequency, there was a greater depletion of gland Ca concentration than at lower frequencies. The data indicate that stimulation of the chorda tympani nerve elicits what can be called pure parasympathetic saliva, as neither phentolamine nor propranolol blocked chorda-evoked secretion.