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World J Gastroenterol. May 7, 2006; 12(17): 2767-2769
Published online May 7, 2006. doi: 10.3748/wjg.v12.i17.2767
Effect of somatostatin analogue octreotide injected into the third cerebral ventricle on pentagastrin-induced gastric acid secretion in rats
Feng Gao, Xiu-Fen Hu
Feng Gao, Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei Province, China
Xiu-Fen Hu, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China
Supported by Returned Overseas Scholar Science Research Foundation of Ministry of Education of China, No.2005383
Correspondence to: Professor Feng Gao, Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei Province, China. gaofengwh@yahoo.com.cn
Telephone: +86-27-85726130
Received: August 20, 2005
Revised: September 12, 2005
Accepted: October 9, 2005
Published online: May 7, 2006
Abstract

AIM: To investigate the effect of long-lasting somatostatin analogue octreotide (Oct) injected into the third cerebral ventricle (TCV) on gastric acid secretion in rats.

METHODS: TCVs were cannulated in male Wistar rats anesthetized with sodium pentobarbital. One week later acute gastric lumen perfusion was carried out and gastric acid was continuously washed with 37°C saline by a perfusion pump. Gastric perfusion samples were collected every 10 min and titrated by 0.01 moL/L NaOH to neutral. On the basis of subcutaneous (sc) injection of pentagastrin (G-5, 160 μg/kg), Oct (0.025 μg, 0.05 μg, 0.1 μg, n= 12 in each group) or vehicle (pyrogen-free physiological saline, n= 10) was injected into the TCV. Before and after the TCV injection, 1 h total acid output (TAO) was determined and experimental data were expressed in change rate (%) of TAO.

RESULTS: Oct (0.025, 0.05 and 0.1 μg) injected into the TCV resulted in change rate of 1.56% (P> 0.05), 20.21% (P<  0.01) and 37.82% of TAO (P<  0.001), respectively. Moreover, comparison in change rate of TAO among these 3 doses showed P<  0.05 between 0.025μg and 0.05 μg, P<  0.01 between 0.025 μg and 0.1μg, and P<  0.05 between 0.05μg and 0.1 μg. However, sc injection of 0.05 μg Oct had no effect on G-5 stimulated gastric acid secretion.

CONCLUSION: Octreotide injected into the third cerebral ventricle inhibits gastrin-induced gastric acid secretion in a dose-dependent manner.

Keywords: Octreotide; Somatostatin analogue; Third cerebal ventricle; Gastric acid; Gastrin