Yang Ting-Ting, Niu Ho-Shan, Chen Li-Jen, Ku Po-Ming, Lin Kao-Chang, Cheng Juei-Tang
The School of Chinese Medicine for Post-Baccalaureate, I-Shou University, Yanchao, Kaohsiung City, Taiwan.
Clin Exp Pharmacol Physiol. 2015 Mar;42(3):263-8. doi: 10.1111/1440-1681.12348.
The aim of the present study was to identify the effect of canavanine on the imidazoline receptor because canavanine is a guanidinium derivative that has a similar structure to imidazoline receptor ligands. Transfected Chinese hamster ovary-K1 cells expressing imidazoline receptors (nischarin (NISCH)-CHO-K1 cells) were used to elucidate the direct effects of canavanine on imidazoline receptors. In addition, the imidazoline I3 receptor has been implicated in stimulation of insulin secretion from pancreatic β-cells. Wistar rats were used to investigate the effects of canavanine (0.1, 1 and 2.5 mg/kg, i.v.) on insulin secretion. In addition the a specific I3 receptor antagonist KU14R (4 or 8 mg/kg, i.v.) was used to block I3 receptors. Canavanine decreased blood glucose by increasing plasma insulin in rats. In addition, canavanine increased calcium influx into NISCH-CHO-K1 cells in a manner similar to agmatine, the endogenous ligand of imidazoline receptors. Moreover, KU12R dose-dependently attenuated canavanine-induced insulin secretion in HIT-T15 pancreatic β-cells and in the plasma of rats. The data suggest that canavanine is an agonist of I3 receptors both in vivo and in vitro. Thus, canavanine would be a useful tool in imidazoline receptor research.
本研究的目的是确定刀豆氨酸对咪唑啉受体的作用，因为刀豆氨酸是一种胍衍生物，其结构与咪唑啉受体配体相似。使用表达咪唑啉受体的转染中国仓鼠卵巢-K1细胞（尼查林（NISCH）-CHO-K1细胞）来阐明刀豆氨酸对咪唑啉受体的直接作用。此外，咪唑啉I3受体与胰腺β细胞胰岛素分泌的刺激有关。使用Wistar大鼠研究刀豆氨酸（0.1、1和2.5 mg/kg，静脉注射）对胰岛素分泌的影响。此外，使用特异性I3受体拮抗剂KU14R（4或8 mg/kg，静脉注射）来阻断I3受体。刀豆氨酸通过增加大鼠血浆胰岛素来降低血糖。此外，刀豆氨酸以类似于咪唑啉受体内源性配体胍丁胺的方式增加钙流入NISCH-CHO-K1细胞。此外，KU12R在剂量依赖性地减弱刀豆氨酸诱导的HIT-T15胰腺β细胞和大鼠血浆中的胰岛素分泌。数据表明，刀豆氨酸在体内和体外都是I3受体的激动剂。因此，刀豆氨酸将是咪唑啉受体研究中的一种有用工具。
