放疗对小型猪腮腺颌下腺舌下腺微血管损伤影响的实验研究

目的:观察放疗对小型猪腮腺、颌下腺、舌下腺的微血管损伤状况。方法:将6只实验用小型猪分为2组。2组动物进行放疗,将双侧腮腺、颌下腺、舌下腺加入放射野中,放疗组20Gy/每侧,对照组0Gy/每侧。放疗结束后4 h处死两组动物,取两组动物腮腺、颌下腺、舌下腺标本行HE染色与CD31免疫组化染色,观察放疗早期3种腺体微血管密度变化。结果:两组小型猪腮腺、颌下腺、舌下腺CD31阳性染色颗粒数有显著差异(P＜0.05);3个腺体间统计结果有显著性差异(P＜0.05);腮腺与颌下腺及舌下腺有显著性差异(P＜0.05),颌下腺与舌下腺无显著性差异。结论:放疗可导致小型猪腮腺、颌下腺、舌下腺微血管密度明显减低,且各腺体间微血管密度减低有差异,腮腺的损伤程度大于颌下腺和舌下腺。     

Alpha-D-mannosidase activity in human saliva and rate of production of enzymes by parotid and submandibular glands

The aim of the investigation was to study alpha-D-mannosidase activity in samples of whole, parotid and submandibular saliva and the rate of production of alpha-D-mannosidases by parotid and submandibular glands. alpha-D-mannosidase activity was determined spectrophotometrically and spectrofluorimetrically. alpha-D-mannosidase activity was found at three different pH optima in whole saliva, around pH 4.8, 6.1 and 6.9. In parotid and submandibular saliva there were two different pH optima, around pH 4.8 and 6.1. The rate of production of alpha-D-mannosidase by parotid glands varied between 0.48 and 13.66 U/min and by submandibular glands between 0.25 and 2.52 U/min. The present study shows that two of the three alpha-D-mannosidases found in whole human saliva are produced by parotid and submandibular glands.     

Radionuclide scan imaging of bilateral Warthin’s tumor and chronic inflammation in the submandibular glands of a patient with a history of heavy smoking

Papillary cystadenoma lymphomatosum, or Warthin’s tumor, is a benign tumor, primarily localized in the parotid glands. The tumor is more common in men than women, and it occurs usually in the fifth and sixth decades of life. Smoking seems to be one of the predisposing factors. The case of a 65-year-old man is described; he presented with a chief complaint of swelling in the bilateral parotid and submandibular glands. Imaging revealed a benign tumor in the right parotid gland, but only inflammation in both submandibular and the left parotid glands. A biopsy was carried out after rapidly increased swelling of the left parotid and left submandibular glands. Histopathological examinations revealed chronic sialadenitis. Superficial parotidectomies were performed 7 and 21 months after the initial visit on the right parotid and the left parotid glands, respectively. Histopathological examination revealed Warthin’s tumor in both parotid glands, with fibrogenesis and chronic sialadenitis in the submandibular glands.     

Altered glycogen metabolism in the submandibular and parotid salivary glands of rats with streptozotocin-induced diabetes

Experimental animal models of diabetes induced either by alloxan or streptozotocin have been used to study aspects of the pathophysiology of this disease. The purpose of this study was to examine the metabolism of glycogen in the submandibular and parotid salivary glands of diabetic rats. Diabetes was induced by an intraperitoneal injection of streptozotocin. Eight weeks after the induction of diabetes, the animals were sacrificed and the submandibular and parotid salivary glands were removed. The glands were analyzed for glycogen concentration, and activities of glycogen synthase and phosphorylase. Although the diabetic rats consumed more food than controls, they had a lower body weight eight weeks after diabetes induction. Glycogen concentration in the submandibular and parotid glands increased by about 27% and 130%, respectively. Glycogen phosphorylase a in the submandibular gland of diabetic rats showed a reduction of between 75% and 68% compared with controls. In parotid glands, phosphorylase a was reduced by between 84% and 79% compared with controls. The increase in the activity of glycogen synthase a (active) varied from 64% to 130% for the submandibular glands and from 75% to 110% for the parotid compared with controls. These results suggest that the diabetic state influences glycogen metabolism in the submandibular and parotid salivary glands of rats.     

Quantitative analysis of normal major salivary glands using computed tomography

OBJECTIVES: We sought to calculate the size and the computed tomography (CT) number of normal parotid and submandibular glands and to evaluate their relationship with respect to sex, age, and obesity in the Korean population. STUDY DESIGN: The authors investigated the axial CT images of 42 healthy volunteers. The maximum cross-sectional area (MCSA) was used as an indicator of the size of the gland. Three regions of interest on axial scans were selected to calculate the mean CT number. RESULTS: There was a significant decrease in the mean MCSA of the submandibular gland and the CT number of both glands with age. The MCSA of the submandibular gland in males was larger than that in females. There was a close correlation between the parotid and the submandibular glands with respect to the CT number, as well as between the left and right glands with respect to the MCSA and the CT number. The body mass index was positively correlated with the MCSA of the parotid gland, whereas the body mass indexes and the CT numbers of both glands were negatively correlated. CONCLUSIONS: Both age and obesity are closely correlated with the size and the CT number of the major salivary glands. Moreover, the correlation between the CT numbers of the parotid and the submandibular glands may be used for diagnostic purposes.     

Glycogen content and activities of enzymes involved in the carbohydrate metabolism of the salivary glands of rats during postnatal development

Carbohydrate metabolism was examined in the developing rat salivary glands by analysing enzymatic activity and glycogen content in the postnatal parotid and submandibular glands. The following enzymes of the carbohydrate metabolism, hexokinase (HK), phosphofructokinase-1 (PFK-1), pyruvate kinase (PK), glucose-6-phosphate dehydrogenase (G6PD), and lactate dehydrogenase (LDH) as well as the content of glycogen were determined in the salivary glands of rats aged 2, 7, 14, 21, 30 and 60 days. The specific activity of HK increased from days 2 to 21 and then it decreased up to 60 days old. The values found for the submandibular glands were from 2.5 to 4.9 times higher than those found for the parotid gland, except for rats aged 60 days. PFK-1 showed a different pattern of variation between the glands. In the submandibular gland there was a statistically significant increase in PFK-1 specific activity from 2 to 30 days of age and then, in the 60 days old group a return to level of the rats aged 2 days. In parotid gland, the specific activity of PFK-1 decreased between 2 and 7 days of age, from 7 to 14 days the specific activity increased markedly and from 14 to 60 days old it gradually decreased. The specific activity of PK followed the same pattern of variation in the submandibular and parotid glands, showing no great variation. The specific activity of LDH decreased from 2 to 60 days old in the submandibular glands. In the parotid glands the mean values for this enzyme were higher for the 2 days old group, and then decreased to remained more or less constant. The potential capacity of the pentose phosphate pathway was greater than that of glycolysis at early ages. The glycogen content showed similar variation in both glands. It was initially high and then decreased. In conclusion, our results on the activities of enzymes involved in carbohydrate metabolism in submandibular and parotid glands may be relevant to the initiation of saliva secretion in these animals.     

Sympathectomy-induced increases in calcitonin gene-related peptide (CGRP)-, substance P- and vasoactive intestinal peptide (VIP)-levels in parotid and submandibular glands of the rat

The neuropeptide contents of rat salivary glands were increased four weeks after sympathetic postganglionic denervation (but not after preganglionic denervation): calcitonin gene-related peptide (CGRP) by 400 and 65% in the parotid and submandibular glands, respectively; substance P by 30% in the submandibular gland; and vasoactive intestinal peptide (VIP) by 30% in the parotid gland. The sensory neurotoxin capsaicin prevented the expected increases of CGRP and substance P in the submandibular glands and of VIP in the parotid glands. The CGRP-increase in the parotid gland was, however, only reduced (by 65%). Parasympathetic otic ganglionectomy reduced the peptide levels in the parotid glands (CGRP--50%, VIP--98% and substance P--99%). From these residual levels, CGRP increased almost 8-fold and substance P 3-fold in response to the sympathetic denervation, while VIP was unaffected. In the parasympathetically denervated glands, the capsaicin-sensitive contribution to the CGRP-response to sympathetic denervation was roughly estimated to be more than 25% but less than 40%, while the corresponding contribution to the substance P-response was roughly estimated to be more than 6% but less than 58%. Most likely not only CGRP/substance P-containing sensory C-fibres (submandibular and parotid glands) but also parasympathetic VIP-containing secretomotor and vasomotor fibres (parotid glands) contributed to the capsaicin-sensitive response to sympathetic denervation.     

Characterization of cGMP-related phosphodiesterase isoenzymes in rat salivary glands

 Isolation and characterization of the cGMP-related phosphodiesterase (PDE) isoenzymes in rat salivary glands were investigated. Both cGMP- and cAMP-PDE activities were mainly present in the 100 000 g supernatant fractions from the parotid, submandibular, and sublingual glands. The results of inhibition studies and ion-exchange chromatography suggest that Ca²⁺/calmodulin markedly stimulates PDE1 in the parotid and sublingual glands, and slightly in the submandibular gland. PDE2 was detected only in the parotid gland. PDE3 was identified in the parotid and submandibular glands. PDE5 was detected in the submandibular and sublingual glands by using inhibition studies, ion-exchange chromatography, and Western blotting. Received: August 21, 2001 / Accepted: May 28, 2002     

Expression of muscarinic receptor subtypes in salivary glands of rats, sheep and man

In rat parotid, submandibular and sublingual glands and in ovine parotid and in human labial glands, the expression of muscarinic receptor subtypes was examined by immunoblotting and immunohistochemistry. Functional correlates were searched for in rat salivary glands. In the rat submandibular and sublingual glandular tissues clear signals of muscarinic M1 and M5 receptors could be detected in the immunoblotting and vague bands for muscarinic M3 and, in particular for, M4 receptors. The rat parotid gland differed. In this gland, the signal was less obvious for the muscarinic M1 receptor, and further, muscarinic M4 receptors appeared more strongly marked than in the submandibular glands. The results from the immunohistochemistry could be interpreted as the muscarinic M4 receptors are located on nerve fibres, since the outer layer of lobuli were densely stained. Intraglandular vessels in the rat submandibular and parotid glands showed expression of M3 receptors. In contrast to the parotid gland, the submandibular vessels also expressed M1 and M2 receptors. Occasionally M5 receptors appeared in the arteries and veins also. The functional studies in the rat confirmed muscarinic M1 receptor mediated secretion in the submandibular gland. Since the M1 receptor blockade did not affect submandibular blood flow, indirect vascular effects could not in total explain the secretory inhibition. Also in the human labial glands, muscarinic M1, M3 and M5 receptors occurred. No or low amounts of muscarinic M2 and M4 receptors could be detected. In patients with Sj?gren-like symptoms an up-regulation of M3, M4 and M5 receptors was apparent in the labial glands. In ovine parotid glands all receptors could be detected, but constantly with vague bands for muscarinic M2 receptors. In conclusion, muscarinic M1 receptors seem to be expressed in seromucous/mucous glands. A secretory effect by muscarinic M5 receptors is not to be excluded, since they were expressed in all the glands examined. However, other functions, such as promotion of inflammation, cell growth and proliferation are possible as well.     

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.     

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.     

Salivary glands: applied anatomy and clinical correlates.

The major salivary glands include the paired parotid, submandibular and sublingual glands. Salivary glands act as accessory digestive glands and produce a secretion referred to as saliva. Saliva has lubricating, cleansing, digestive and antimicrobial properties. The parotid is the largest salivary gland and saliva is secreted into the mouth via the parotid duct (Stensen's duct). The submandibular gland lies inferior to the body of the mandible and is susceptible to sialolithiases. Drainage is via the duct of the submandibular gland (Wharton's duct) into the floor of the mouth on either side of the lingual frenulum. The sublingual glands are situated under the mucosa in the floor of the mouth, on the sides of the tongue. These glands are in relationship to important nerves in the surrounding tissue. Disease processes such as chronic intraparenchymal sialolithiasis and neoplastic changes frequently mandate surgical removal of the underlying salivary gland. Detailed, applied knowledge of anatomy on a regional basis is required to avoid inadvertent nerve damage during surgery and resulting litigation.     

The host defense peptide LL‐37 is detected in human parotid and submandibular/sublingual saliva and expressed in glandular neutrophils

The human host defense peptide, LL‐37, is an important player in the first line of defense against invading microorganisms. LL‐37 and its precursor, hCAP18, have been detected in unstimulated whole saliva but no reports showing hCAP18/LL‐37 in isolated, parotid, and/or submandibular/sublingual saliva have been presented. Here, we measured the levels of hCAP18/LL‐37 in human parotid and submandibular/sublingual saliva and investigated the expression of hCAP18/LL‐37 in parotid and submandibular gland tissue. Parotid and submandibular/sublingual saliva was collected from healthy volunteers, and the levels of hCAP18/LL‐37 in saliva were analyzed by dot blot, ELISA, and western blotting. Cellular expression of hCAP18/LL‐37 in human parotid and submandibular glands was investigated by immunohistochemistry. Immunoreactivity for hCAP18/LL‐37 was detected in both parotid and submandibular/sublingual saliva of all individuals. The concentration of hCAP18/LL‐37 was similar in parotid and submandibular/sublingual saliva, and was determined by densitometric scanning of each dot and normalization to the total protein concentration of each sample, and by ELISA. Double immunohistochemistry revealed that intravascular neutrophils of both parotid and submandibular glands express hCAP18/LL‐37. For the first time, we demonstrate hCAP18/LL‐37 in isolated human parotid and submandibular/sublingual saliva and expression of hCAP18/LL‐37 in glandular intravascular neutrophils, indicating that neutrophils of the major salivary glands contribute to the LL‐37 content of whole saliva.     

Relative secretory contributions of the three major salivary glands of the rat in response to substance P and super-sensitivity

In vivo salivation in the rat in response to a range of intravenous doses of substance P was studied. The ducts of the parotid, submandibular and sublingual glands were cannulated. The secretory threshold dose of substance P, in microgram/kg, was 0.05-0.1 in the submandibular glands, 0.2 in the parotid glands and 0.2-0.5 in the sublingual glands. The maximal secretory response in all three types of glands was obtained at a dose level of 5-10 micrograms/kg. The total amount of saliva secreted at this dose level from the three pairs of glands was calculated to about 300 mg; the submandibular glands were responsible for 65 per cent, the parotid glands for 32 per cent and the sublingual glands for 3 per cent. Parasympathetic decentralization but not sympathetic denervation caused the sublingual glands to develop a super-sensitivity to substance P. The secretory effect of substance P was not exerted via cholinergic, alpha-adrenergic or beta-adrenergic receptors.     

Tissue distribution of RNAs for cystatins, histatins, statherin, and proline-rich salivary proteins in humans and macaques

The tissue distribution of the mRNAs for a number of salivary proteins [proline-rich proteins (PRPs), statherin, cystatins, and the histatins] has been examined in humans and macaques in order to investigate their possible functions and tissue-specific regulation. We have shown that PRP RNAs (0.8-1.5 kb) are expressed in human and rhesus parotid and submandibular glands, and in the human bronchus. The genes for the acidic and basic PRPs are differentially regulated in these tissues. RNAs for acidic PRPs are predominantly expressed in the submandibular gland, for basic PRPs in the respiratory tract, and for both acidic and basic PRPs in the parotid gland. Protein studies of secretions from these tissues confirm the RNA results. Statherin RNA (0.65 kb) was detected in human and rhesus parotid and submandibular glands and the human bronchus, as well as in rhesus lacrimal glands. Statherin was found by tissue immunoperoxidase staining in the serous cells of respiratory tract submucosal glands, which is the same location for the synthesis of PRPs. Several cystatin RNAs (0.8-1.3 kb) were differentially expressed in human parotid glands, submandibular glands, and the bronchus, and in lacrimal glands from both rhesus and cynomolgus macaques. RNAs (0.6 kb) for the histatins were found only in parotid and submandibular glands. Thus, it appears that PRPs, statherin, and cystatins may play a broader role in the physiology of biological fluids and secretions than previously suspected, since they are found in secretions other than saliva. However, the functions of the histatins are restricted to saliva. These studies also pose some interesting questions regarding the differential expression of these genes in a variety of secretory tissues.     

Sialin(SLC17A5)在腮腺、颌下腺及颌下腺细胞系HSG表达的初步分析

目的研究唾液酸转运蛋白Sialin在正常涎腺组织和颌下腺细胞系HSG的表达.方法应用基因芯片检测正常人腮腺、颌下腺组织Sialin编码基因SLC17A5的表达;提取腮腺、颌下腺组织及颌下腺细胞系(HSG)总RNA,通过RT-PCR在基因水平上验证SLC17A5基因的表达;提取HSG细胞总蛋白,用免疫印迹法检测Sialin在蛋白水平表达.结果基因芯片检测到Sialin编码基因SLC17A5基因在正常人腮腺、颌下腺均有表达,表达比值分别为226、206.9,不存在表达差异;RT-PCR验证芯片结果并在其他涎腺样本及颌下腺细胞系HSG中能扩增出其全部翻译区1485bp的片段,应用商业化的抗体能够在HSG细胞检测到Sialin相应的约54KDa蛋白.结论正常腮腺、颌下腺组织和颌下腺细胞系HSG均表达SLC17A5基因,但是唾液酸转运蛋白Sialin在组织、细胞内定位和功能需要进一步研究.     

5种哺乳动物和人涎腺组织学及超微结构观察

目的研究5种动物涎腺组织形态学及超微结构特点.方法选用成年小型猪5只,猕猴2只,新西兰白兔7只、Wistar大鼠7只和昆明小鼠7只及人类正常腮腺和颌下腺组织各一例,行腮腺和颌下腺组织学、组织化学及超微结构观察.结果5种动物的腮腺组织学表现差异不明显,均为浆液性腺体.5种动物的颌下腺组织学差异较大,人、小型猪、猕猴颌下腺均为混合性腺体,而大、小鼠和兔颌下腺为浆粘液性腺体.组化染色结果表明形态相似的腺泡细胞,其合成产物不尽相同.5种动物腮腺和颌下腺腺泡细胞在超微结构方面除分泌颗粒表现出明显的差异外,其余结构差异不明显.结论在小型猪、猕猴、兔、大鼠和小鼠5种动物的涎腺组织学及超微结构上,猕猴和小型猪与人类最接近.     

Absorbed Radiation Doses During Tomographic Examinations in Dental Implant Planning: A Study in Humans

Objective: The aim of this human study was to evaluate the radiation doses in the buccal cavity and face, during panoramic, spiral conventional tomography, and helicoidal computerized tomography exams. Material and Methods: Lithium fluoride TL detectors (TLD‐100) were placed on the skin at anatomic points such as parotid glands, submandibular glands, thyroid glands, and crystalline to assess the skin entrance dose in 19 patients who were to undergo dental implant surgery. Results: In the panoramic exam, maximum doses were observed near the parotid glands at 1.57 (±18%) mGy on the right and 1.89 (±18%) mGy on the left. In the spiral conventional tomography exam, the maximum dose was 4.41 (±21%) mGy near the right and left parotid glands, whereas near the right or left submandibular glands, the maximum doses reached 40.7 (±18%) mGy. In the helicoidal computerized tomography for mandibular and maxilla exams, the maximum dose was 40.9 (±15%) mGy near the parotid glands and 41.0 (±18%) mGy near the submandibular glands. Near the thyroid and eye lens, doses were lower than 0.23 (±21%) in all exams. Conclusion: Regardless of the exam target area, the submandibular and parotid glands represented the most irradiated organs. This data suggests that efforts should be made by professionals to improve and optimize methods in order to reduce doses without losing the information necessary for treatment planning.     

Secretory responses to autonomic stimulation of rat salivary glands following reserpine treatment

The response to stimulation of the parasympathetic innervation to parotid or submandibular glands of reserpinized rats was altered from that of untreated rats. Thus, acute reserpinization, like other types of sympathectomy, resulted in increase in volume of parasympathetically-evoked parotid or submandibular saliva when comparison was made with evoked saliva from untreated glands. As norepinephrine is depleted by reserpine, there was no response to stimulation of sympathetic nerves to these reserpinized glands. Adrenergic receptors were normally activated by administration of autonomic agonists. Thus a single high dose of reserpine can cause the same effects as those induced by chronic administration of low doses of reserpine, i.e. a 3-fold increase in calcium (Ca) concentration of submandibular gland but no change in Ca concentration of parotid gland. Although sympathetic stimulation caused no change in Ca concentration of submandibular or parotid glands of reserpine (acute)-treated rats, stimulation with isoproterenol (25 mg/kg, i.p., 60 min) produced a 32-35 per cent decrease in glandular Ca concentration from that of unstimulated reserpinized glands. Glands of untreated rats showed a 52 per cent depletion after 60 min of isoproterenol stimulation; however, Ca output in parotid saliva from reserpinized rat for 60 min of stimulation was not changed from that of untreated rats, but that of submandibular saliva was two times greater. Ca concentration of submandibular saliva was unchanged during 60 min-stimulation of reserpine-treated rats, but that of untreated rats decreased.