Effects of Prolonged Administration of Atropine and Pilocarpine on the Submaxillary Gland of the Cat.

Abstract

Some days after parasympathetic decentralisation of the submaxillary gland, brought about by cutting the chorda tympani, the secretory cells of the gland show an increased sensitivity t o chemical agents. This was first demonstrated by MAEVSKY (1923), using adrenaline as a secretory stimulus. The "paralytic secretion'' of saliva appearing after cutting the chorda (CLAUDE BERNARD, 1864) is very likely evoked by adrenaline (noradrenaline) acting on the supersensitive gland cells, since it is observed only under experimental conditions causing a sympathetic hyperactivity or an augmented discharge of hormone from the adrenal medulla (EMMELIN and MUREN, 1950).Injection of atropine renders the gland cells insusceptible t o parasympathetic impulses, and treatment of the submaxillary gland with atropine over a period of several days gives rise to a supersensitivity of the gland cells to chemical stimuli just as does exclusion of parasympathetic impulses by section of the chorda tympani. A cat treated for some time with atropine exhibits a "paralytic secretion'' under the same experimental conditions as a cat with severed chorda tympani. On the other hand, if a submaxillary gland deprived of parasympathetic impulses through chorda section is supplied witch secretory stimuli by repeated injections of pilocarpine over a suitable period, no supersensitiv-

Choline Acetylase in Normal and Denervated Salivary Glands

“…2 shows that the results are similar to those obtained after section of the chorda-lingual nerve, indicating that if there was such damage to postganglionic neurons it was negligible. contralateral gland [Emmelin, Jacobsohn and Muren, 1951]. In the present studies a similar gain of weight, though not necessarily significant, was also observed.…”

Variation in the response to ductal obstruction of feline submandibular and sublingual salivary glands and the importance of the innervation

“…The ultrastructural appearance of the chorda included in the ligation is one of extensive loss of axons and demonstrates the damage that the parasympathetic supply suffers by inclusion of the chorda. Destruction of the chorda is itself followed by glandular atrophy (10)(11)(12)(13), which was reported to be greater in rodents (14).…”

Effects of Atropine Treatment on the Submaxillary Gland of Rats

“…Thus, both procedures induce a supersensitivity of the cat's submaxillary gland to secretory agents [Emmelin, Jacobsohn and Muren, 1951]. When given repeatedly to rats for 1 week the doses of atropine used in the present investigation were found to increase the sensitivity of the submaxillary gland to secretory agents, such as adrenaline and isoprenaline.…”

“…In addition, a supersensitivity to secretory agents develops in chronically denervated glands according to Cannon's 'Law of Denervation'. The effect of atropine treatment (which might be described as pharmacological parasympathetic denervation) differs from that of surgical denervation in that the weight of glands in cats does not decrease after atropine treatment [Emmelin, Jacobsohn and Muren, 1951]. In the present investigation the effects of atropine treatment were further studied, on the rat's submaxillary gland, and compared with those of parasympathetic denervation.…”