[The salivary glands within the history of physiology].

In the rapid development of physiology during the second half of the 19th century the salivary glands played a remarkable part. Numerous of the famous physiologists of that age used these glands in experiments, which yielded new knowledge of far-reaching importance, particularly to neurophysiology. Nerves with hitherto unknown functions were found when Carl Ludwig discovered the secretory nerves and Claude Bernard the vasodilator nerves in experiments on the submaxillary gland.

Nerve-induced secretion of parotid acinar granules in cats.

Electron microscopy of cat parotid glands revealed great heterogeneity in the secretory granules of normal unstimulated acinar cells. Electrical stimulation of the parasympathetic nerve to the gland evoked a copious flow of parotid saliva which was accompanied by an extensive depletion of the secretory granules from the acinar cells. Exocytosis was captured as it was occurring by means of perfusion-fixation, and showed that the events occur in a conventional manner.

Protein secretion from the cat parotid gland on nerve stimulation.

1. The output and composition of proteins in nerve stimulated saliva samples were compared. 2.

Secretion of amylase from the rat parotid salivary gland after degeneration of the auriculotemporal nerve.

The output of amylase into saliva secreted after injection of methacholine or substance P was increased after parasympathetic denervation, but the salivary concentration of amylase was unchanged. The increased output corresponded to the increased flow. Isoprenaline injected during the methacholine-induced secretion raised the output, more being secreted from the denervated than from the contralateral gland.