Marino L R, Sugano K, Yamada T
Department of Pediatrics, University of Michigan Medical Center, Ann Arbor 48109.
Am J Physiol. 1988 Jan;254(1 Pt 1):G87-92. doi: 10.1152/ajpgi.1988.254.1.G87.
To examine the ontogeny of gastrin synthesis and posttranslational processing mechanisms, we utilized region-specific antisera to determine the factors that regulate the contents of gastrin and its precursors in the stomachs of developing rats. Gastrin content increased gradually from birth to a peak at 5 wk of age, after which there was a slight decrease to levels observed in mature animals. Unlike gastrin, glycine-extended precursors of gastrin (G-Gly) increased abruptly in the first day of life but thereafter increased at a steady state. Dexamethasone treatment and early weaning (at 11 days of age) rapidly increased gastrin content, whereas G-Gly content was decreased. On weaning animals to adult rat chow abruptly at an age (18 days) when the corticosteroid surge associated with the weaning process had already occurred, evidence for increases in both gastrin and G-Gly content were observed 7 days later. In contrast, administration of dexamethasone to 18-day-old rats enhanced gastrin content to a greater extent than G-Gly. These results suggest that the natural surge in corticosteroids associated with weaning may enhance gastrin amidation activity, whereas the concomitant dietary changes may exert a stimulatory effect of gastrin synthesis.
为了研究胃泌素合成的个体发生及翻译后加工机制，我们利用区域特异性抗血清来确定调节发育中大鼠胃内胃泌素及其前体含量的因素。胃泌素含量从出生后逐渐增加，在5周龄时达到峰值，之后略有下降至成熟动物的水平。与胃泌素不同，胃泌素的甘氨酸延伸前体（G-Gly）在出生第一天急剧增加，但此后以稳定状态增加。地塞米松治疗和早期断奶（11日龄）迅速增加胃泌素含量，而G-Gly含量降低。在动物于18日龄时突然断奶至成年大鼠饲料，此时与断奶过程相关的皮质类固醇激增已经发生，7天后观察到胃泌素和G-Gly含量均增加的证据。相比之下，给18日龄大鼠注射地塞米松对胃泌素含量的增强程度大于G-Gly。这些结果表明，与断奶相关的皮质类固醇自然激增可能增强胃泌素酰胺化活性，而同时的饮食变化可能对胃泌素合成产生刺激作用。
