Kristensson Elin, Sundqvist Monika, Håkanson Rolf, Lindström Erik
AstraZeneca R&D, Integrative Pharmacology, GI Biology, Mölndal, Sweden.
J Endocrinol. 2007 May;193(2):245-50. doi: 10.1677/JOE-07-0028.
Ghrelin is produced by gastric A-like cells and released in response to food deprivation. Interestingly, psychological stress also raises circulating ghrelin levels. This study compared plasma ghrelin levels in Sprague-Dawley (SPD) rats and high-anxiety Wistar Kyoto (WKY) rats. The two strains were also compared with respect to plasma gastrin, a gastric hormone with a pre- and postprandial release pattern opposite to that of ghrelin, and to the activity of the gastrin-dependent, histamine-forming ECL cells in the gastric mucosa. The rats were killed after being freely fed or after an over-night fast. The stomachs were weighed and tissue samples were collected for histological and biochemical analysis. Plasma ghrelin and gastrin levels were determined by RIA. While fasted SPD rats had higher plasma ghrelin levels than fasted WKY rats (P < 0.001), plasma ghrelin did not differ between freely fed rats of the two strains. Gastrin levels were higher in fed WKY rats than in fed SPD rats (P < 0.001). Despite the higher plasma gastrin level, the oxyntic mucosal histidine decarboxylase (HDC) activity (a marker of ECL-cell activity) in fed rats and the mucosal thickness did not differ between the two strains. In a subsequent study, rats were subjected to water-avoidance stress for 60 min, causing plasma gastrin to increase in WKY rats (P < 0.001) but not in SPD rats. In conclusion, high-anxiety WKY rats had lower circulating ghrelin and higher gastrin than SPD rats in both the fasted and fed state, while the ECL-cell activity (HDC activity) was only moderately affected.
胃饥饿素由胃A型细胞产生，并在饥饿状态下释放。有趣的是，心理应激也会使循环中的胃饥饿素水平升高。本研究比较了斯普拉格-道利（SPD）大鼠和高焦虑的Wistar京都（WKY）大鼠的血浆胃饥饿素水平。还比较了这两个品系大鼠的血浆胃泌素水平，胃泌素是一种胃激素，其餐前和餐后释放模式与胃饥饿素相反，同时比较了胃黏膜中依赖胃泌素的组胺生成肠嗜铬样（ECL）细胞的活性。大鼠在自由进食或禁食过夜后处死。称量胃的重量，并收集组织样本进行组织学和生化分析。通过放射免疫分析法测定血浆胃饥饿素和胃泌素水平。禁食的SPD大鼠的血浆胃饥饿素水平高于禁食的WKY大鼠（P < 0.001），但两个品系自由进食大鼠的血浆胃饥饿素水平没有差异。喂食的WKY大鼠的胃泌素水平高于喂食的SPD大鼠（P < 0.001）。尽管血浆胃泌素水平较高，但两个品系喂食大鼠的胃黏膜组胺脱羧酶（HDC）活性（ECL细胞活性的标志物）和黏膜厚度没有差异。在随后的一项研究中，大鼠接受60分钟的避水应激，导致WKY大鼠的血浆胃泌素增加（P < 0.001），而SPD大鼠没有增加。总之，在禁食和喂食状态下，高焦虑的WKY大鼠的循环胃饥饿素水平低于SPD大鼠，胃泌素水平高于SPD大鼠，而ECL细胞活性（HDC活性）仅受到中度影响。
