Effects of surgical denervations on the autonomic nerves in parotid glands of dogs

Garrett, J. R.; Holmberg, Jan

doi:10.1007/bf00306964

Cited by 22 publications

(5 citation statements)

References 17 publications

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“…The increase in enzyme activity seems to depend on an intact auriculo-temporal nerve, since after severance of this nerve in both groups the choline acetyltransferase activity of the gland 3 weeks later is not higher in the rats on bulk diet than in those on control diet. The small residual enzyme activity probably reflects the presence of cholinergic neurones left unsevered at the operation, as seems to be the case after denervation of the cat's and dog's parotid glands [Nordenfelt, 1963;Garrett, 1966a and b;Garrett and Holmberg, 1972;Holmberg, 1971Holmberg, , 1972Ekstr6m and Holmberg, 1972b;Ekstr6m and Emmelin, 1974a and b].…”

Section: Discussionmentioning

confidence: 99%

Choline Acetyltransferase Activity in Rat Salivary Glands After Cellulose Rich Diet or Treatment With an Atropine‐like Drug

Ekström

1974

Exp Physiol

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When rats are fed on dry, cellulose rich diet the choline acetyltransferase activity of the parotid gland increases, provided the auriculo-temporal nerve is intact. Dryness of the oral mucosa produced by atropinization is also followed by an increase in enzyme activity of the gland. It is suggested that the increased activity of the acetylcholinesynthesizing enzyme is due to enhanced traffic of secretory impulses in the parasympathetic nerves to the gland, reflexly elicited by the two kinds of treatment.When parasympathetic neurones of salivary glands are disconnected from the central nervous system a gradual decrease of the capacity to synthesize acetylcholine in the glands occurs, as judged by the activity of choline acetyltransferase [Nordenfelt, 1964;Ekstrom and Holmberg, 1972a]. If a liquid diet is given to rats the parotid gland atrophies [Hall and Schneyer, 1964;Wells and Peronace, 1967] and the choline acetyltransferase activity of the gland decreases [Ekstrom, 1973]; the diet appears to diminish the traffic of secretory impulses to the gland. It seems reasonable that a dry, cellulose rich diet would have the opposite effect, increasing the reflexly elicited stimulation of the gland; such a diet has, in fact, been found to cause a gain in weight of the salivary glands [Wells, 1967;Wells and Peronace, 1967]. Another way of increasing reflexly the flow of secretory impulses to the glands would be to produce dryness of the oral mucosa by giving an atropine-like drug.In the present experiments the effect of a dry diet or of prolonged atropinization on the choline acetyltransferase activity of salivary glands was studied. One series of animals was exposed to both measures. METHODSAltogether eighty-six rats, 3-7 months old, of a Sprague-Dawley strain bred at this Institute were used. Litter mates served as controls. Food and water were given ad libitum. The experiments were performed as follows:1. Treatment with bulk diet. The control rats were given a pelleted standard diet for rats (Astra-Ewos), while litter mates received a pelleted bulk diet made from the standard diet but containing 20% cellulose instead of the usual 3%. This bulk diet was considered to be suitable, since it caused about the same body-weight changes as the standard diet. In preliminary experiments a diet of about 50% cellulose was tried, but this content of cellulose led to body-weight losses and reduction of the weights of the submaxillary glands. Moreover, some of the operated rats died during the experimental period when given food with such a high content of cellulose.Eighteen male rats were used for the study on the choline acetyltransferase activity 191

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Section: Discussionmentioning

confidence: 99%

Choline Acetyltransferase Activity in Rat Salivary Glands After Cellulose Rich Diet or Treatment With an Atropine‐like Drug

Ekström

1974

Exp Physiol

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“…Other anomalies exist (see Garrett, 1987b). Any contributions from the facial nerve, which passes in the vicinity of the glands, have yet to be fully evaluated (see Garrett and Holmberg, 1972;Ekstrom et al, 1988).…”

Section: Introductionmentioning

confidence: 99%

The innervation of salivary glands as revealed by morphological methods

Garrett

Kidd

1993

Microscopy Res & Technique

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Salivary secretion is nerve mediated. The salivary glands are supplied by parasympathetic and sympathetic efferent nerves which travel to the glands by separate routes. Once in the glands the axons from each type of nerve intermingle and travel together in association with Schwann cells, forming Schwann-axon bundles. Two types of neuro-effector relationships exist with salivary parenchymal and myoepithelial cells: epilemmal (outside the parenchymal basement membrane) and hypolemmal (within the parenchymal basement membrane). Their relative frequencies with either type of nerve differ greatly between glands and species. Salivary blood vessels receive epilemmal innervations by both sympathetic and parasympathetic axons. The classical transmitters--acetylcholine in parasympathetic and noradrenaline in sympathetic axons--are stored in small vesicles. A variety of non-conventional neuropeptide transmitters have also been found in salivary nerves by immunohistochemistry, and they occur in large dense-cored vesicles. Prolonged high frequency stimulation has been found to cause depletion of large dense-cored vesicles from glandular nerves. In recent years afferent nerves have started to be identified and are found in greatest numbers around the main salivary ducts, where they may form a hypolemmal association with the epithelial cells. Functional studies demonstrate complex interactions between parasympathetic and sympathetic nerves. Morphological assessments of changes in the parenchymal cells after nerve stimulations or denervations add greatly to our understanding of the nerve functions. At least four types of influence can be exerted on salivary parenchymal cells by the nerves: hydrokinetic (water mobilizing), proteokinetic (protein secreting), synthetic (inducing synthesis), and trophic (maintaining normal functional size and state). In respect to each role, wide glandular and species differences exist between the relative contributions made by each type of nerve.

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“…This remarkable ability of the gland to regenerate allows the investigation of innervation mechanisms normally only present during the embryonic and neonatal development of salivary glands. Following ligation, as atrophy develops, acinar cell volume reduces, axon length is reduced and nerves appear to lose contact with salivary cells ( Garrett et al 1979 ). The total level of choline acetyltransferase, a good marker for parasympathetic nerves, is also reduced, suggesting fewer cholinergic nerves ( Banns et al 1979 ).…”

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confidence: 99%

Altered plasticity of the parasympathetic innervation in the recovering rat submandibular gland following extensive atrophy

Carpenter

Khosravani

Ekström

et al. 2009

Experimental Physiology

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Adult rat submandibular glands have a rich autonomic innervation, with parasympathetic and sympathetic nerves working in synergy rather than antagonistically. Ligation of the secretory duct rapidly causes atrophy and the loss of most acini, which are the main target cell for parasympathetic nerves. Following deligation, there is a recovery of gland structure and function, as assessed by autonomimetic stimulation. This study examines whether the parasympathetic nerves reattach to new target cells to form functional neuro-effector junctions. Under recovery anaesthesia, the submandibular duct of adult male rats was ligated via an intra-oral approach to avoid damaging the chorda-lingual nerve. Four weeks later, rats were either killed or anaesthetized and the ligation clip removed. Following a further 8 weeks, both submandibular ducts were cannulated under terminal anaesthesia. Salivary flows were then stimulated electrically (chorda-lingual nerve at 2, 5 and 10 Hz) and subsequently by methacholine (whole-body infusion at two doses). Glands were excised, weighed and divided for further in vitro studies or fixed for histological examination. Ligation of ducts caused 75% loss of gland weight, with the loss of most acinar cells. Of the remaining acini, only 50% were innervated despite unchanged choline acetyltransferase activity, suggesting few parasympathetic nerves had died. Following deligation, submandibular glands recovered half their weight and had normal morphology. Salivary flows from both glands (per unit of gland tissue) were similar when evoked by methacholine but greater from the deligated glands when evoked by nerve stimulation. This suggests that parasympathetic nerves had reattached to new target cells in the recovered glands at a greater ratio than normal, confirming reinnervation of the regenerating gland.

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Effects of surgical denervations on the autonomic nerves in parotid glands of dogs

Cited by 22 publications

References 17 publications

Choline Acetyltransferase Activity in Rat Salivary Glands After Cellulose Rich Diet or Treatment With an Atropine‐like Drug

Choline Acetyltransferase Activity in Rat Salivary Glands After Cellulose Rich Diet or Treatment With an Atropine‐like Drug

The innervation of salivary glands as revealed by morphological methods

Altered plasticity of the parasympathetic innervation in the recovering rat submandibular gland following extensive atrophy

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