Zong Ya-Feng, Chen Wei-Hua, Zhang Yuan-Shu, Zou Si-Xiang
Department of Animal Physiology and Biochemistry, Nanjing Agricultural University, Nanjing 210095, Jiangshu Province, China.
World J Gastroenterol. 2007 Apr 14;13(14):2094-9. doi: 10.3748/wjg.v13.i14.2094.
To investigate the in vivo effect of beta-casomorphin-7 on the regulation of gastric somatostatin and gastrin messenger RNA in rat gastric mucosa.
Somatostatin and gastrin mRNA were quantified by RT-PCR and in situ hybridization (ISH) in 24 rats. The rats were divided into three treatment groups: basal diet + physiological saline (n=8), basal diet + beta-casomorphin-7 (7.5 x 10(-7)mol) (n=8), and basal diet + poly-Gly-7 (containing equal mol of N with 7.5 x 10(-7) mol beta-casomorphin-7) (n=8). After oral administration for 30 days, rats were killed by exsanguinations.
After intra-gastric administration of beta-casomorphin-7 for 30 d, gastrin mRNA increased by 52.8% (P<0.05, n=8), and somatostatin mRNA levels decreased by 30.7% compared with the controls (P<0.01, n=8). No significant differences in the expression of the two genes were observed in the poly-Gly-treated group, although gastrin mRNA expression was elevated by 35.6% as against the control group (P=0.15, n=8). The long-term oral administration of a casomorphin solution significantly decreased the even gray of D-cells, but did not lower the number of D-cells both in the antrum and fundus. Interestingly, the number of G-cells increased in the antrum and fundus, but its average density was augmented only in the antrum.
Beta-casomorphin-7 is capable of modulating gene expression of the regulatory peptides from G and D cells. Data from in situ hybridization studies indicate that beta-casomorphin-7 affects gastrin gene expression indirectly by means of the paracrine action of somatostatin, and depends on its intrinsic molecular function.
研究β-酪蛋白吗啡-7对大鼠胃黏膜中胃生长抑素和胃泌素信使核糖核酸调节的体内作用。
采用逆转录聚合酶链反应(RT-PCR)和原位杂交(ISH)技术对24只大鼠的生长抑素和胃泌素信使核糖核酸进行定量分析。将大鼠分为三个治疗组:基础饮食+生理盐水(n = 8)、基础饮食+β-酪蛋白吗啡-7(7.5×10⁻⁷mol)(n = 8)和基础饮食+聚甘氨酸-7(含与7.5×10⁻⁷molβ-酪蛋白吗啡-7等摩尔的氮)(n = 8)。口服给药30天后,通过放血处死大鼠。
胃内给予β-酪蛋白吗啡-7 30天后,与对照组相比,胃泌素信使核糖核酸增加了52.8%(P<0.05,n = 8),生长抑素信使核糖核酸水平降低了30.7%(P<0.01,n = 8)。聚甘氨酸处理组中这两种基因的表达无显著差异,尽管胃泌素信使核糖核酸表达相对于对照组升高了35.6%(P = 0.15,n = 8)。长期口服酪蛋白吗啡溶液显著降低了胃窦和胃底D细胞的灰度,但未降低其数量。有趣的是,胃窦和胃底的G细胞数量增加,但其平均密度仅在胃窦增加。
β-酪蛋白吗啡-7能够调节G细胞和D细胞中调节肽的基因表达。原位杂交研究数据表明,β-酪蛋白吗啡-7通过生长抑素的旁分泌作用间接影响胃泌素基因表达,并取决于其内在分子功能。