Effect of parasympathectomy on the salivary secretion of submandibular gland in rats / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of parasympathectomy on secretion of submandibular glands and the feasibility of treatment for xerostomia in rats.</p><p><b>METHODS</b>Twenty Sprague-Dawley male rats weighing 200 - 300 g were randomly divided into the experimental group (n = 12), in which the right chorda-lingual nerve was cut, and the control group (n = 8). The secretion of submandibular gland was measured for 5 min by Schirmer test for both groups.</p><p><b>RESULTS</b>The stimulated saliva flow rate decreased on 1st, 12th and 24th week after denervation in the right operated submandibular glands (P < 0.05). No difference in secretion was found between the left non-operated glands and the control group. Comparing with the left non-operated gland and the control gland, the saliva flow rate at rest in the right operated submandibular gland increased on the 1st, 12th and 24th week (P < 0.05).</p><p><b>CONCLUSIONS</b>After parasympathectomy of rat submandibular glands, the saliva flow rate at rest increased in the denervated gland, which suggests that parasympathectomy of submandibular gland might be used as a therapy for xerostomia.</p>

Sympathetic and parasympathetic regulation of sodium transporters and water channels in rat submandibular gland

The present study was aimed to explore the role of sympathetic and parasympathetic nerves in the regulation of sodium transporters and water channels in the salivary gland. Rats were denervated of their sympathetic and parasympathetic nerves to the submandibular gland, and the glandular expression of sodium transporters and water channels was determined by Western blot analysis. The expression of either alpha1 or beta1 subunit of Na, K-ATPase was not significantly affected either by the sympathetic or by the parasympathetic denervation. The expression of subunits of epithelial sodium channels was significantly increased both in the denervated and contralateral glands either by the sympathetic or by the parasympathetic denervation. Neither the sympathetic nor the parasympathetic denervation significantly altered the expression of aquaporin-1 (AQP1). Nor was the expression of AQP4 affected significantly by the parasympathetic or the sympathetic denervation. On the contrary, the expression of AQP5 was significantly increased not only by the parasympathetic but also by the sympathetic denervation. These results suggest that sympathetic and parasympathetic nerves have tonic regulatory effects on the regulation of certain sodium transporters and AQP water channels in the salivary gland.

Autonomic Neural Regulation of Sodium Transporters and Water Channels in Rat Submandibular Gland

The present study was undertaken to explore the role of autonomic nerves in the regulation of sodium transporters and water channels in the salivary gland. Rats were denervated of their sympathetic or parasympathetic nerves to the submandibular gland. One week later, the expression of Na,K-ATPase, epithelial sodium channels (ENaC), and aquaporins (AQP) was examined in the denervated and contralateral glands. The sympathetic denervation slightly but significantly decreased the expression of alpha1 subunit of Na,K-ATPase, whereas the parasympathetic denervation increased it. The expression of alpha-subunit of ENaC was significantly increased in both the denervated and contralateral glands either by the sympathetic or parasympathetic denervation. The sympathetic denervation significantly increased the expression of AQP5 in both the denervated and contralateral glands, whereas the parasympathetic denervation decreased it. It is suggested that the autonomic nerves have a tonic effect on the regulation of sodium transporters and AQP water channels in the salivary gland.

Effect of preganglionic parasympathetic denervation on Nitric Oxide synthase in submandibular gland of adult albino rat

Adult albino rats were subjected to chorda tympani neurectomy on the right side and the left side served as the control. After different survival periods, the control and experimental submandibular glands were discected out and processed for histological and histochemical examinations. Chorda tympani neurectomy resulted in atrophic changes in about 90% of both seromucous acini and granular convoluted tubules of the submandibular gland. They showed statistically significant reduction in their mean diameters after denevation. The reduction in the diameter of the acini was more marked than that of the tubules. The atrophic acini became separated by wide spaces and their cells showed cytoplasmic vacuolation two weeks after chorda tympani neurectomy. At the third and the fourth weeks, an insignificant increase in the diameter was noticed in the tubules and acini. The interlobular striated ducts showed cytoplasmic vacuolation two weeks after denervation which became more prominent during the third and fourth week after chorda tympani neurectomy. After denervation, NADPH-d positive nerve terminals were absent around the majority of acini and the granular convoluted tubules and were seen around the remaining 7-10% of the acini and 10-23% of the tubules. Throughout the period of denervation, NADPH-d positive nerve terminals were found around the striated ducts, the interlobular ducts and the blood vessels. The majority of the NADPH-d positive nerve terminals around the acini and granular convoluted tubules are parasympathetic in origin derived from the chorda tympani. The origin of NADPH-d positive nerve fibers around some acini and granular convoluted tubules and in relation to the remaining duct system and blood vessels needs further investigation

Altered expression of sodium transporters and water channels following sympathetic and parasympathetic denervation in rat submandibular gland

The flow of saliva is controlled entirely by nervous stimuli. The present study was aimed to explore the role of sympathetic and parasympathetic nerves in the regulation of sodium transporters and water channels in the salivary gland. Rats were denervated of their sympathetic and parasympathetic nerves to the submandibular gland, and the expression of sodium transporters and water channels was determined. The expression of either alpha-1 or beta-1 subunit of Na, K-ATPase was not significantly affected by the sympathetic denervation. On the contrary, the expression of both subunits was decreased by the parasympathetic denervation. The expression of alpha-, beta-, and gamma-subunits of ENaC was not significantly affected by the sympathetic denervation, but was increased by the parasympathetic denervation. On the contrary, the expression of NHE3 was markedly decreased by both the sympathetic and the parasympathetic denervation. The sympathetic denervation significantly increased the expression of AQP1, while the parasympathetic denervation was without effect. The sympathetic and parasympathetic denervation significantly increased the expression of AQP4. The sympathetic denervation did not affect the expression of AQP5, but the parasympathetic denervation significantly decreased it. These results suggest that sympathetic and parasympathetic nerves have tonic effects on the regulation of sodium transporters and AQP water channels in the salivary gland. The sympathetic and parasympathetic denervation may then result in alterations of secretory rate and electrolyte composition of the saliva.

Altered Expression of Aquaporins in Rat Submandibular Glands after Parasympathetic Denervation

The salivary glands produce 1.5L of fluid per day. As in other exocrine organs, the general mechanism in the salivary glands is that water movement occurs secondary to osmotic driving forces created by active salt transport. Therefore, high water permeability in the salivary glands is expected to have a variety of aquaporin (AQP), a water channel. Although some AQPs have been known to be present in the salivary glands, roles of parasympathetic nerve in AQP expression have not yet been examined. This study was designed to examine the changes of AQPs and extracellular signal-regulated kinase (ERK) in the submandibular glands after parasympathetic denervation. Right chorda-lingual nerve was cut, and each right (experiment) and left (control) submandibular gland was excised at 1, 3, 7, 14, 30 days after denervation. The denervated right submandibular glands were resulted in weight loss and morphologic changes, including cell loss and atrophy, as the time elapsed after parasympathetic denervation increased, whereas there were no histologic alteration in control side. AQP5 which is known to reside in apical membrane and secretory caraliculi of the submandibular acini were gradually underexpressed according, as the time after denervation increased. Expression of AQP4 in submandibular ductal epithelium was down-regulated after denervation. Besides, AQP3 and 8, which is known to be present in basolateral membrane of the glandular acini, were gradually underexpressed after denervation, similar to the pattern of other types. Expression of ERK, a mitogen-activated protein kinase, was downregulated after parasympathetic denervation in the submandibular gland. These results suggest that parasympathetic nervous system regulates the expression of AQPs in salivary glands, and is in part mediated by ERK pathway.

Headache in chagasic women

O proposito do estudo foi comparar a frequencia de cefaleia entre mulheres chagasicas e nao-chagasicas. O estudo retrospectivo compreendeu 647 mulheres com idade >ou= 40 anos, chagasicas (n=362) e Controles (n=285) atendidas em um Hospital Universitario brasileiro. As chagasicas foram classificadas nas formas clinicas; cardiacas (n=179), megas (n=58) e indeterminada (n=125). Cefaleia foi definida de acordo com os criterios da Headache International Society. A idade (57,0 +ou- 11,3 versus 57,3 +ou- 10,4 anos) e a percentagem de mulheres de cor branca (75,8 por cento versus 77,1 por cento) foram semelhantes entre chagasicas e controles, respectivamente...

Despopulaçäo neuronal cardíaca em hamsters (Mesocricetus auratus) cronicamente infectados com Trypanosoma cruzi / Cardiac neuronal depopulation in hamsters (Mesocricetus auratus) chronically infected with Trypanosoma cruzi

Com o objetivo de se obter um modelo experimental que permitisse estabelecer a despopulaçäo (desnervaçäo) neuronal cardíaca procurou-se pesquisar o comportamento do sistema nervoso intracardíaco em hamsters cronicamente infectados com o T. cruzi. Para tal fim, realizaram-se contagens dos neurônios do plexo nervoso autonômico intracardíaco em hamsters inoculados com 35.000 formas sanguíneas de três cepas diferentes, sacrificados 5, 8 e 10 meses depois da infecçäo. Demonstrou-se, pela primeira vez, destruiçäo neuronal significativa num modelo experimental, similar à que ocorre na doença de Chagas humana