摘要目的 通过观察不同年龄段人体和比格犬的胃底黏膜组织形态和胃主细胞超微结构,了解增龄对胃分泌胃蛋白酶原能力的影响.方法 选取因消化不良症状拟行胃镜检查的患者50例为研究对象,分为中青年组(20～59岁)19例,低龄老年组(60～69岁)11例,中龄老年组(70～79岁)10例和高龄老年组(≥80岁)10例.另选择19只健康比格犬作为研究对象,分为中青年组(1～5岁)8只,低龄老年组(6～8岁)5只,高龄老年组(≥9岁)6只.光学显微镜下观察人体和比格犬胃底黏膜组织形态,测定固有膜厚度和主细胞数目.透射电子显微镜下定量观察人体和比格犬胃主细胞超微结构,计算分泌颗粒(也称为酶原颗粒)面积分数.数据采用单因素方差分析比较.结果 人体和比格犬各年龄组间胃底腺形态无明显变化.不同年龄组的人体和比格犬胃底固有膜厚度比较,差异均无统计学意义(P均＞0.05).人体中青年组、低龄老年组、中龄老年组、高龄老年组主细胞数分别为(71.79±16.85)、(52.73±16.60)、(57.10±20.21)、(43.70±16.89)/高倍视野,随增龄而减少(F=6.431,P=0.001).比格犬中青年组、低龄老年组、高龄老年组主细胞数分别为(328.38±32.36)、(341.21±42.49)和(225.67±52.19)/高倍视野,随增龄而减少(F=13.647,P＜0.01).人体和比格犬胃主细胞超微结构随增龄有退化表现,粗面内质网扩张,核糖体缺失,分泌颗粒稀疏减少等.人体中青年组、低龄老年组、中龄老年组、高龄老年组胃主细胞分泌颗粒面积分数分别为(67.28±3.79)％、(66.88±4.84)％、(65.63±7.10)％和(56.25±8.47)％,随增龄而减少(F=6.069,P=0.002).比格犬中青年组、低龄老年组、高龄老年组胃主细胞分泌颗粒面积分数分别为(58.83±3.07)％、(52.34±4.73)％和(39.89±4.46)％,随增龄而减少(F=38.837,P＜0.01).结论 胃底腺分泌胃蛋白酶原能力随增龄而下降,这可能是老年人功能性消化不良发生的原因之一.

abstractsObjective To investigate the effect of aging on gastric pepsinogen secretion through observing histological changes of gastric fundal mucosa and ultrastructure of gastric chief cells in human and Beagle dogs at different ages.Methods Fifty middle-aged and elderly indigestion patients with gastroscopy were selected as study objects and divided into young and middle age group (age 20-59 years,n=19),junior elderly group (age 60-69 years,n=11),middle elderly group (age 70-79 years,n=10),and senior elderly group (no less than 80 years,n=10).In addition,nineteen healthy Beagle dogs were also selected as study objects and divided into young and middle age group (age between 1 to 5 years,n=8),junior elderly group (age six to eight years,n=5),and senior elderly group (no less than 9 years,n=6).The histology and morphology of gastric fundal mucosa of human and Beagle dogs were observed under light microscope.Then the thickness of lamina propria was measured and the number of gastric chief cells was counted.The ultrastructure of gastric chief cells was observed under electron microscope,and the area percentages of secretory granule(also called mucous granule)area in cytoplasm of chief cell was calculated.The data was analyzed by one-way analysis of variance.Results No significant histological and morphological changes of gastric fundal mucosa were observed in human and Beagle dogs at different ages.There was no significant difference in the thickness of lamina propria among different ages in human and Beagle dogs (all P＞0.05).The number of human chief cells of young and middle age group,junior elderly group,middle elderly group and senior elderly group was 71.79±16.85,52.73±16.60,57.10±20.21 and 43.70 ±16.89/high power field (HPF),respectively,which decreased as age increased (F=6.431,P=0.001).The numbers of chief cells of young and middle age group,junior elderly group,and senior elderly group of Beagle dogs were 328.38 ±32.36,341.20 ±42.49 and 225.67 ± 52.19/HPF,respectively,which decreased as age increased (F=13.647,P＜0.01).Aging-related degeneration was founded in ultrastructure of gastric chief cells in human and Beagle dogs including rough endoplasmic reticulum dilation,ribosones missing,secretory granule decreasing and so on.The area percentages of secretory granule area in cytoplasm of human chief cells of young and middle age group,junior elderly group,middle elderly group and senior elderly group were (67.28±3.79)％,(66.88±4.84)％,(65.63±7.10)％ and (56.25±8.47)％,respectively,which decreased as age increased (F=6.069,P=0.002).The area percentages of secretory granule area in cytoplasm of Beagle dogs' chief cells of young and middle age group,junior elderly group,and senior elderly group were (58.83 ± 3.07) ％,(52.34 ± 4.73) ％ and (39.89 ± 4.46) ％,respectively,which decreased as age increased (F=38.837,P＜0.01).Condusion As age increased,the ability of pepsinogen secretion of fundal gland decreased,which may be one of the reasons of functional dyspepsia in the eldly.