Morphological and biochemical changes in the rat parotid gland after compensatory and isoproterenol-induced enlargement

Enlargement of parotid glands can be induced in rats by treatment with isoproterenol (ISP) or by removal of the submandibular and sublingual glands. In this study, morphological changes in the enlarged parotid glands and qualitative changes in secreted proteins were examined in rats that had been treated with ISP for 10 days or that had been partially sialoadenectomized by removal of the submandibular/sublingual glands 2 weeks prior to killing. After ISP treatment or salivary gland ablation, secretory cells were enlarged and contained enlarged secretory granules that stained differently from granules in normal glands. Isoproterenol treatment induced the greatest enlargement of cells and granules. Even though gland structure was altered in both experimental groups, electrophoresis of saliva showed that submandibular/sublingual gland ablation did not lead to significant qualitative changes in secreted proteins, while ISP treatment induced major changes in the pattern of secreted protein. The results suggest that compensatory enlargement of the parotid glands and changes after ISP treatment are induced by stimulation of different regulatory pathways.     

Morphological alterations of the parotid gland of rats maintained on a liquid diet

The purpose of this study was to analyze the morphological alterations that occurred in the parotid glands of rats maintained on a liquid diet compared to a solid diet. Thirty-six animals were randomly divided into two groups. The control group received a solid diet, and the experimental group received a liquid diet. The animals were killed after 8, 15 and 30 days. The glands were prepared for inclusion in paraffin and analyzed with a light microscope. The results showed a statistically significant reduction of the parotid gland weight of the animals from the experimental group compared to the control group at 15 and 30 days. The strongest morphological alteration displayed was the presence of cytoplasm vacuoles on the parotid glands of the animals maintained on the liquid diet. Specific stain techniques for glycoproteins and mucopolysaccarides could not identify the substances inside the vacuoles observed in the experimental animals. We conclude that a liquid diet caused atrophy of the parotid gland after 15 and 30 days.     

Changes in parotid gland morphology and function in patients treated with intensity-modulated radiotherapy for nasopharyngeal and oropharyngeal tumors

Objective

To evaluate the morphological changes of the parotid glands in patients treated with intensity-modulated radiotherapy (IMRT) for nasopharyngeal and oropharyngeal tumors and the correlations with parotid function.

Methods

Ten patients with nasopharyngeal and oropharyngeal tumors treated with IMRT between May 2009 and January 2010 at Hokkaido University Hospital were included in this study. In the morphological assessment of the parotid glands, the sizes and computed tomography (CT) numbers of the bilateral parotid glands before and after IMRT with CT were calculated. For functional assessment of the parotid glands, we conducted the Saxon test and used a visual analog scale (VAS) for xerostomia evaluation.

Results

Reductions in saliva secretion were observed in the patients treated with IMRT for nasopharyngeal and oropharyngeal tumors, and there was a significant correlation between the reduction in saliva secretion and the VAS. The reductions in the parotid gland size and CT number were larger on the ipsilateral side than on the contralateral side. The reduction in saliva secretion was not significantly correlated with the reduction in parotid gland size, but was significantly correlated with the reduction in CT number.

Conclusions

Morphological and functional changes of the parotid glands were observed after IMRT for nasopharyngeal and oropharyngeal tumors, and preservation of the contralateral parotid glands was only partly achieved. Among the morphological changes of the parotid glands, the CT number may be considered a predictor of parotid function after radiotherapy.     

Low-frequency noise effects on the parotid gland of the Wistar rat

BACKGROUND: Long-term low-frequency noise (LFN) (相似文献   

Radioprotection of the mice parotid gland by isoproterenol: study on morphometry of secretory granules and on autoradiography

Objectives The aim of the present study was to investigate the effect of radiosensitivity on acinar cells in the parotid gland when the secretory granules were released. Methods The parotid glands of mice were exposed to 10 Gy of X-radiation when the acinar cells were degranulated with isoproterenol (IPR). Three days later, morphological images and number and area of secretory granules within the acinar cells in the parotid glands were obtained and light microscope autoradiography (LMARG) was performed using ³H-leucine. Results The light microscopy images showed a disorderly arrangement and pycnosis of acinar cells and cellular atrophy in irradiated groups. The changes were milder in IPR-administered groups than in non-IPR-administered groups. The number of secretory granules in irradiated groups, which included both IPR-administered and non-IPR-administered sets, was significantly less than that in nonirradiated groups. The number of silver grains within acinar cells obtained by LMARG in the non-IPR-administered set of irradiated groups was significantly lower than that in the nonirradiated group or the IPR-administered set after 30 min of radioisotope administration, and it was significantly higher than that of the nonirradiated group after 240 min. Conclusions When the secretory granules of acinar cells in mouse parotid gland were degranulated by isoproterenol, alleviation of the effects of radiation exposure on morphological change as well as the ingestion and egestion of secretory substances were indicated.     

单一剂量单侧腮腺放射损伤对双侧腮腺结构和功能的影响

目的 研究单一大剂量射线照射单侧小型猪腮腺对双侧腮腺结构和功能影响。方法 14只小型猪一侧腮腺用直线加速分别给予15 Gy（7只）和20 Gy（7只）离子射线照射,4只做为空白对照。分别在放射前,放射后4周和16周观察腮腺唾液流率、腺体重量、腺泡面积和组织学变化。结果 4周时,15 Gy和20 Gy照射后放射侧腮腺重量下降达50%;15 Gy照射后放射侧腮腺唾液流率无明显下降,20 Gy照射后放射侧腮腺唾液流率减少约50％。16周时,15 Gy和20 Gy照射后放射侧腮腺重量下降达50%,组织学明显改变,照射后放射侧腮腺流率分别下降约60%及80%。非放射侧腮腺重量及形态均无明显变化,但20 Gy照射后16周时非放射侧腮腺唾液流率明显下降。结论 单一剂量照射后腮腺结构的改变相对唾液流率下降发生较早,唾液流率减少与腺泡面积的减少不完全成正相关。非照射侧腮腺形态变化不明显,但唾液流率明显下降。     

The human accessory parotid gland: its incidence, nature, and significance.

Observations on ninety-six dissections of human parotid glands have been presented, with the incidence, size, location, and histologic features of accessory parotid glands noted. Twenty-one per cent of the dissections revealed clearly detached accessory glands at variable distances from the main gland. There were no appreciable histopathologic differences between the accessory gland and the main gland in the same facial half. Aging changes, such as decreased glandular elements, increased fat, and increased fibrous connective tissue, were not more extensive in the accessory gland than in the main gland. Because of the histologic similarity, pathoses of the main gland could also involve the accessory parotid gland. Failure to remove a distantly separated accessory gland during parotidectomy could be a cause of tumor recurrence. X-ray films and sialograms were examined for visualization of accessory parotid glands and their ducts. Whereas routine diagnostic x-ray films were limited in their usefulness, sialograms provided visualization of accessory glands for diagnostic purposes.     

腮腺主导管结扎及再通后腺泡凋亡与再生变化规律的研究

目的:研究大鼠腮腺主导管结扎及再通后腺泡凋亡与再生的变化规律。方法:通过对大鼠右侧腮腺主导管双重结扎14 d后再通,建立腮腺组织萎缩后再生模型。分别于主导管再通术后0、1、3、5、7、10、14和21 d获取腮腺组织标本,应用HE和AB-PAS染色观察腺体的组织学变化,免疫组织化学染色法检测腺泡中增殖细胞核抗原(PCNA)、半胱氨酸天冬氨酸蛋白水解酶3(Caspase3)的表达。结果:组织学观察见:主导管结扎14 d后腺泡萎缩、消失,导管样结构增多,酶原颗粒消失;主导管再通术后,腺泡再生,导管样结构减少,酶原颗粒数目恢复正常。免疫组织化学染色分析结果示:在主导管结扎14 d后PCNA散在表达,主导管再通1 d后表达增加,5 d后达峰值,7 d后降低并趋于平稳;主导管结扎14 d及再通后Caspase3表达水平持续较低,且平稳。各实验组间PCNA表达差异有统计学意义(P＜0.05),而Caspase3表达差异无统计学意义。结论:腮腺主导管持续结扎14 d后再通,萎缩的腺泡可再生,形态及功能均可恢复正常水平,表明主导管持续结扎14 d对腺体组织造成的损伤完全可逆。     

Changes in rat parotid salivary proteins induced by chronic isoproterenol administration.

Changes in the rat parotid gland and its secretion, brought about by chronic isoproterenol administration, were studied. In addition to the expected enlargement, morphological and biochemical analyses of the glands showed evidence of changes in the secretory components. Chromatographic and electrophoretic experiments revealed both qualitative and quantitative changes in the secretory proteins.     

Postnatal changes in calcium and amylase of rat salivary glands, including calcium changes with senescence

Postnatal changes occur in glandular Ca concentration of rat parotid and submandibular glands. At 4 days of age, Ca concentration was low in both glands (only one-third to one-half that of adults) and increased gradually with age. The pattern of change was generally similar for male and female rats, but in submandibular gland, adult levels of 9-10 m-equiv./kg were reached by weaning, whereas for parotid gland, a gradual increase in Ca concentration occurred with adult levels of 9-10 m-equiv./kg reached by 7 weeks of age. The pattern of change was the same whether Ca concentration was expressed per kg wet or dry weight albeit water content changed with age. The changes in Ca concentration of parotid paralleled the age-associated increases in amylase activity of parotid gland. Amylase activity of submandibular gland was much less than that of parotid and similarly low at all ages examined, and did not parallel the age-associated increases in Ca concentration. The regulatory role of the sympathetic innervation on glandular Ca concentration was examined by effecting surgical denervation of parotid and submandibular glands at 8 days of age, and then determining Ca concentration of the denervated glands at 32 days. A three-fold increase in Ca concentration, similar to that following acute sympathectomy in adults, occurred in submandibular gland but no change was seen in parotid. An unexpectedly high concentration of Ca was also found in submandibular (but not parotid) gland of old rats.     

小型猪与小鼠腮腺、泪腺、垂体超微结构的观察与比较

目的 研究小型猪及小鼠腮腺的超微结构特点,并将腮腺与泪腺、垂体的超微结构对比观察,旨为涎腺基因治疗转基因表达的生物学特性提供腺体形态学的依据.方法选用成年小型猪、昆明种小鼠各5只,分别取腮腺、泪腺、垂体进行超微结构观察.结果小型猪较小鼠的腮腺腺泡细胞内分泌颗粒密度大,质地均匀,细胞器少见,血管内皮细胞内有较多分泌颗粒存在.小型猪与小鼠泪腺超微结构均与各自腮腺相似,小型猪与小鼠垂体结构特点为细胞排列散在,细胞间充满血窦及毛细血管.结论小型猪腮腺腺泡细胞分泌颗粒多,其毛细血管内皮细胞中也可见较多分泌颗粒,提示这些分泌颗粒可能进入血液发挥内分泌功能.     

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目的 探讨采用肿瘤及其就位腺体区域性切除的方法治疗腮腺浅叶良性肿瘤的可行性。方法 对2004—2006年甘肃嘉峪关市第一人民医院口腔科收治的28例腮腺浅叶良性肿瘤患者,采用肿瘤及其就位腺体区域性切除+局部面神经解剖并且保留腮腺主导管的术式治疗,术后随访观察疗效。结果 28例腮腺浅叶良性肿瘤患者治疗后,经过3～5年的随访无一例复发,均达到治愈目的。术后并发症：出现面神经颧支暂时性瘫痪1例,颊支暂时性瘫痪2例,经应用营养神经药物治疗,1 ~ 3个月后均恢复正常;发生腮腺局部积液4例,经穿刺抽液换药,加压包扎后均得到痊愈,无一例涎瘘发生;出现味觉出汗综合征1例,但范围较小;愈后检查患者,手术侧凹陷不明显,面部左右基本对称,腮腺检查分泌功能基本正常。结论 肿瘤及其就位腺体区域性切除的方法是治疗腮腺浅叶多形性腺瘤或其他良性肿瘤合适的手术方式。与标准的保留面神经的肿瘤及腮腺浅叶或全腮腺切除术相比,能减少面神经损伤、涎瘘、味觉出汗综合征的发生,更重要的是能够保持面部形态的对称性,避免畸形等并发症的发生。     

Effects of adriamycin on calcium concentration and morphology of mouse salivary glands

A large single dose (15 mg/kg body wt, ip) of the antitumor agent adriamycin (ADR) caused a marked increase in calcium concentration of submaxillary gland of female mice, and a smaller increase in the parotid gland within 2 days of injection. A small dose (2.5 mg/kg body wt) had no effect. The histological appearance of the glands was also changed and included an increase in size of granules and acinar cells of the submaxillary glands and a decrease in size of acinar cells of the parotid. At the EM level, there was evidence of mitochondrial alteration in the parotid but not in the submaxillary glands. Rough endoplasmic reticulum (RER) was markedly disorganized in the parotid, and abnormal whorls of RER were evident. Submaxillary glands showed no change in RER. Water content of either gland was unchanged from that of controls. Heart ventricles, unexpectedly, showed no change in calcium concentration from that of control tissues, at 3 h, 1, 2 or 4 days after ADR administration. The [Ca] changes induced by ADR in the submaxillary glands are not mediated via beta-adrenoceptor activation since propranolol did not alter the ADR-induced changes. The marked difference in response of the glands (and heart) to ADR, suggests that the mechanisms involved in calcium homeostasis in these organs are very different.     

Alteration of membrane phospholipids in hypertrophied rat salivary glands induced by chronic administration of isoproterenol

Hypertrophy of parotid and submandibular glands, and elevated phospholipid content per gland in both were induced. However, phospholipid content per tissue weight increased only in the parotid gland. Sublingual gland phospholipids were unaffected with regard to the gland weight and phospholipid content; phospholipid class compositions were altered in each of the three glands, typically an increase of phosphatidylcholine and decreases of sphingomyelin and phosphatidic acid. Concerning fatty-acyl groups in phospholipid, prominent increase of octadecadienoic acid was observed in total and individual phospholipids of both parotid and submandibular glands. However, eicosatetraenoic acid decreased in the total phospholipids of these two glands. In the sublingual gland, phospholipids, fatty-acyl compositions were not changed by isoproterenol. The results suggest that isoproterenol-induced changes of membrane phospholipids are regulated by at least two different effects, one for fatty-acyl groups and another for base moieties of phospholipids.     

腮腺主导管结扎后腺体的组织学变化

目的:探讨腮腺导管结扎后腺体组织的生物学变化.方法:用SD大鼠建立动物模型,将其右侧腮腺主导管结扎;定期获取标本,制备组织切片,利用苏木精-伊红染色、免疫组织化学染色及形态计量等方法,观察术后不同阶段腮腺组织中腺泡、肌上皮细胞、导管及间质的形态变化及体积分数.结果:腮腺主导管结扎后,腺体组织开始萎缩,其中腺泡体积分数逐...     

Effects of zinc deficiency on rat parotid gland

Hitherto, the effect of zinc deficiency on the rat parotid gland was not known. Male rats were fed cither a low zinc diet (0.4–0.8 ppm Zn) or a zinc adequate diet (approximately 40 ppm Zn) for 35–42 days. The experimental animals exhibited retarded body growth, anorexia, loss of hair and decreases in plasma and hair zinc levels. In comparison to the ad libitum controls, the parotid glands of the pair-fed group showed a decrease in cell number, but an increase in cell mass, protein and amykisc content. In the parotid glands of the experimental group, cell number was comparable to the pair-fed group, but there was a decrease in cell mass and protein content as compared to the pair-fed group. These findings suggest that zinc deficiency and its associated reduced food intake impair growth of the parotid gland and, further, that zinc deficiency per se appears to lead to a diminution in gland protein synthesis. It is proposed that a compromise in parotid gland function could be a contributory factor underlying the increased susceptibility to dental caries known to occur in zinc deficiency.     

Pathological changes following retrograde infusion of methyl violet in the parotid gland of the miniature pig]

OBJECTIVE: To investigate the pathologic changes induced by infusion of 1% methyl violet in the parotid gland of the miniature pig (minipig). METHODS: Methyl violet (either 0.6 ml, 1.0 ml, or 4.0 ml) was injected into parotid glands of fifteen minipigs. The parotid glands were harvested for gross and histopathologic study after 1 week, 2 weeks, 1 month, 3 months and 6 months. RESULTS: The pathological changes induced by retrograde injection of methyl violet included necrosis or atrophy of acinar cells and fibrosis of the gland. The ductal system underwent atrophic changes, and thrombotic obliteration of main duct. CONCLUSION: Retrograde infusion of 1% methyl violet results in complete atrophy and fibrosis of the parotid gland in the minipig.     

Growth of rat salivary glands after terbutaline or dobutamine

Six days after commencement of a regimen of twice daily administration of 25, 50, or 75 mg/kg body wt doses of the beta 1 adrenergic agonist, dobutamine, or the beta 2 adrenergic agonist, terbutaline, submandibular and parotid glands of rats were enlarged in size. The beta 1 receptor was responsible for mediation of these changes with both agonists, since the effects of either agonist were prevented when a 10 mg/kg dose of the beta 1 antagonist, atenolol, was injected 20 min prior to the agonists but were not prevented when the beta 2 antagonist butoxamine, was given prior to each agonist. The increase in gland size caused by dobutamine was more marked than that induced by terbutaline; total amount of DNA of the parotid gland was also higher with dobutamine than with terbutaline. The response of the parotid gland to each dose of either agonist was greater than that of the submandibular gland, suggesting that the parotid gland has more beta receptors than does submandibular gland. The data also show that the increase in cell size precedes an increase in cell number. The increase in cell size depends on activation of fewer receptors than are required for the increase in DNA, since at the same dose of dobutamine, e.g., increase in cell size but not cell number was observed; moreover, the same dosage effected an increase in DNA of parotid but not submandibular gland. The data thus show that enlargement of both glands, as well as increase in size and number of their acinar cells, is dependent on activation of beta 1 adrenoceptors only.     

Effects of zinc deficiency on rat parotid gland

Hitherto, the effect of zinc deficiency on the rat parotid gland was not known. Male rats were fed either a low zinc diet (0.4-0.8 ppm Zn) or a zinc adequate diet (approximately 40 ppm Zn) for 35-42 days. The experimental animals exhibited retarded body growth, anorexia, loss of hair and decreases in plasma and hair zinc levels. In comparison to the ad libitum controls, the parotid glands of the pair-fed group showed a decrease in cell number, but an increase in cell mass, protein and amylase content. In the parotid glands of the experimental group, cell number was comparable to the pair-fed group, but there was a decrease in cell mass and protein content as compared to the pair-fed group. These findings suggest that zinc deficiency and its associated reduced food intake impair growth of the parotid gland and, further, that zinc deficiency per se appears to lead to a diminution in gland protein synthesis. It is proposed that a compromise in parotid gland function could be a contributory factor underlying the increased susceptibility to dental cares known to occur in zinc deficiency.     

Acetylcholine synthesis, muscarinic receptor subtypes, neuropeptides and secretion of ferret salivary glands with special reference to the zygomatic gland

Studies on salivary secretion are usually focused on parotid and submandibular glands. However, the film of mucin, that protects the oral structures and is responsible for the feeling of oral comfort, is produced by the submucosal glands. The submucosal zygomatic and molar glands are particularly large in carnivores such as the ferret. Comparisons between the mucous sublingual, zygomatic and molar glands, serous parotid and sero-mucous submandibular glands showed the acetylcholine synthesis, in terms of concentration, to be three to four times higher in the mucous glands than in the parotid and submandibular glands. Bromoacetylcholine inhibited 95-99% of the synthesis of acetylcholine in the incubates of the five types of glands, showing the acetylcholine synthesis to depend on the activity of choline acetyltransferase. The high acetylcholine synthesis in the zygomatic gland was of nervous origin, since cutting the buccal nerve, aiming at parasympathetic denervation, and allowing time for nerve degeneration, reduced the acetylcholine synthesising capacity of the gland by 95%. A similar reduction (96%) in the parotid gland followed upon the avulsion of the parasympathetic auriculo-temporal nerve. Zygomatic saliva was very viscous. The salivary flow rate in response to electrical stimulation (20 Hz) of the buccal nerve (zygomatic gland), expressed per gland weight, was one-third of that to stimulation of the auriculo-temporal nerve (parotid gland) or the chorda-lingual nerve (submandibular gland). As previously shown for the parotid and submandibular gland, a certain fraction (25%) of the parasympathetic secretory response of the zygomatic gland depended on non-adrenergic, non-cholinergic transmission mechanisms, probably involving substance P and vasoactive intestinal peptide and possibly calcitonin gene-related peptide. Particularly, high concentrations of vasoactive intestinal peptide were found in the sublingual and molar glands, and of substance P in the submandibular, zygomatic and molar glands; notably, the concentration of calcitonin gene-related peptide of the sublingual gland was not detectable. All five muscarinic receptor subtypes were detected in the five glands. The receptor protein profile, as judged by immunoblotting and semi-quantitative estimations, was about the same in the glands: high level of M3, low level of M2 and levels roughly in the same range of M1, M4 and M5. Compared to the parotid and submandibular glands, the M5 receptor level was particularly low in the mucin-secreting glands. The present study points out both similarities and dissimilarities between the five types of glands investigated. The zygomatic gland, in particular, appears to be a suitable model for future studies aiming at causing relief of dry mouth by local pharmacological treatment.