Histamine and calcium secretion in the submandibular gland of the cat evoked by two types of stimulation.

The aim of this work was to compare the pools of histamine and calcium in the submandibular gland of the cat during two kinds of stimulation of the gland. Submandibular glands of the cat were stimulated electrically (chorda tympani nerve) and by close arterial infusion of pilocarpine. Each stimulation was adjusted in such a way as to obtain a near maximal secretory response. Concentrations of histamine and calcium were measured in nonstimulated and stimulated glands, in saliva, secreted during stimulation and in the venous outflow from the gland before and during the stimulation. The experiments showed that: pilocarpine stimulation lowered the histamine concentration in the gland more than electrical stimulation of the chorda tympani nerve. Calcium stores in the gland were depleted to the same extent by each type of stimulation. the concentration of histamine and calcium in the saliva produced by close arterial pilocarpine infusion was significantly higher than in the saliva secreted during nerve stimulation. histamine and calcium concentrations were higher in the venous outflow from stimulated glands than before stimulation. The results indicate a close relationship between histamine and calcium in salivary secretion, although the origins of the two substances are different.