Alterations in submandibular and retrolingual glands following parasympathetic denervation in rats

Abstract

Alterations in size and structure of submandibular and retrolingual glands of the rat produced by unilateral sectioning of the chorda tympani, or the lingual nerve, or the glandular branch which leaves the lingual and innervates both glands, are described. The glands were studied 1, 2, 4, 8, 12 and 16 days after nerve section.The weight of the glands increased the first day after nerve section and decreased markedly from then on, reaching 40 to 70% of the initial weight after 16 days. In the glands where the chorda tympani or the lingual nerve were sectioned the increase in weight was attributed to the accumulation of secretion in the acinous cells. After that, a progressive atrophy developed, being more severe in the acini than in the tubes.In the cases where the glandular nerve was sectioned a wide necrosis probably of vascular origin was produced, followed by parenchymatous regeneration. In both cases 16 days after nerve section glands were small, fibrous and with little parenchyma.The role of the parasympathetic nerves in controlling the normal structure of submandibulars and retrolinguals is discussed.The chorda tympani has been sectioned in several animals, chiefly in dogs, cats and rabbits. A summary of the results may be found in the monograph of Burgen and Emmelin ('61). These studies indicated a 30% decrease in submandibular gland size, and, microscopically, a variable atrophy of the different structures with relative increase in connective tissue stroma.Rawlinson ('35) studied the changes produced in the submandibular gland of the cat by sectioning the chorda tympani. He described alterations in the epithelium of striated tubules. Clear areas and vacuoles appeared between the striations and the cells gradually decreased in size with pseudostratification of the nuclei.Lacassagne and Causs6 ('41) sectioned the chorda tympani inside the ear in mice and found considerable changes in submandibular and retrolingual glands. There was also atrophy in the retrolingual glands and in the acinous portion of the submandibular. In females the striated tubules of the submandibulars were permanently atrophic, while in males there was only a slight and transient atrophy. This latter ANAT. REC.. 150: 25-34.effect has been attributed to protective action of androgens.Hillarp ('49) sectioned the chorda tympani inside the ears of rats and found moderate atrophy of tubules and acini.Emmelin, Jacobsohn and Muren ('52) sectioned the chorda tympani in cats. The alterations in the striated tubules were similar to those found by Rawlinson; both also found atrophy in the acini and increase in the connective tissue stroma.Several parasympathetic denervations were performed in our laboratories with the object of studying the role of the chorda tympani in the production of submandibular and retrolingual hypertrophy by repeated incisor amputations (Houssay, Peronace, Perec and Rubinstein, '62). The severe atrophy of the denervated submandibulars and retrolinguals was remarkable. The object of this paper is to study serially ...

Effects of Atropine Treatment on the Submaxillary Gland of Rats

“…The effect of pilocarpine was found to be quite contrary to that of atropine, since this secretory agent decreased the weight of both the denervated and the contralateral gland to a similar level. These findings suggest that the weight increase after parasympathetic denervation is due to the secretory inactivity in the gland, which is in accordance with previous histological studies [Peronace et al, 1964].…”

Roles of lysosomal proteolytic systems in AQP5 degradation in the submandibular gland of rats following chorda tympani parasympathetic denervation

“…Loss of acinar cells due to any mechanism, such as cell death, would cause a decrease in the AQP5 protein level. Furthermore, previous reports showed that the decrease in the SMG weight occurs during the first week after CTD (5,7,32,49). For this reason, we examined the possibility of the involvement of apoptosis following CTD.…”

“…The third effect of CTD on the SMG is a reduction in the gland weight (5,7,32,49). Upon CTD, the gland weight decreases by 50% at the latest by a week after the operation (7,32).…”

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).…”