Hammer R A, Ochoa A, Fernandez C, Ertan A, Arimura A
Department of Medicine, Tulane University Medical School, New Orleans, LA.
Peptides. 1992 Nov-Dec;13(6):1175-9. doi: 10.1016/0196-9781(92)90025-x.
Neurotensin and somatostatin have both been shown to inhibit gastric acid secretion, but no interaction between these peptides has been demonstrated. To determine whether somatostatin might be a mediator of neurotensin's effect on pentagastrin-stimulated gastric acid secretion, we performed the following three experiments. First, we collected 0.2-ml samples of portal venous blood as frequently as every 5 min, and we confirmed a significant release of somatostatin-like immunoreactivity into portal venous blood during neurotensin-induced inhibition of acid secretion. This release of somatostatin-like immunoreactivity and inhibition of acid secretion were only seen in pentobarbital-anesthetized rats, but no sustained release of somatostatin-like immunoreactivity or inhibition of acid secretion occurred in urethane-anesthetized animals. In the second experiment, we analyzed portal plasma by high pressure liquid chromatography, and found that portal somatostatin-like immunoreactivity in blood collected during neurotensin infusion was composed of a single peak corresponding to somatostatin-14. In the third experiment, we found that infusion of antibody to somatostatin prevented neurotensin from inhibiting pentagastrin-stimulated acid secretion. Taken together, these data show that somatostatin, possibly from the stomach itself, is a necessary mediator of neurotensin's inhibitory effect in pentobarbital-anesthetized rats.
神经降压素和生长抑素均已被证明可抑制胃酸分泌，但尚未证实这些肽之间存在相互作用。为了确定生长抑素是否可能是神经降压素对五肽胃泌素刺激的胃酸分泌产生作用的介质，我们进行了以下三个实验。首先，我们每隔5分钟频繁采集0.2毫升门静脉血样本，并证实了在神经降压素诱导的胃酸分泌抑制过程中，门静脉血中生长抑素样免疫反应性物质有显著释放。这种生长抑素样免疫反应性物质的释放和胃酸分泌的抑制仅在戊巴比妥麻醉的大鼠中观察到，而在氨基甲酸乙酯麻醉的动物中未出现生长抑素样免疫反应性物质的持续释放或胃酸分泌的抑制。在第二个实验中，我们通过高压液相色谱法分析门静脉血浆，发现神经降压素输注期间采集的血液中的门静脉生长抑素样免疫反应性物质由一个与生长抑素-14相对应的单峰组成。在第三个实验中，我们发现输注生长抑素抗体可阻止神经降压素抑制五肽胃泌素刺激的胃酸分泌。综上所述，这些数据表明，可能来自胃本身的生长抑素是神经降压素在戊巴比妥麻醉大鼠中产生抑制作用的必要介质。
