| Co-Investigator(Kenkyū-buntansha) |
WAKUI Makoto Hirosaki University, School of Medicine, Professor, 医学部, 教授 (80108505)
KIMURA Ryoichi Hirosaki University, School of Medicine, Assistant, 医学部, 助手 (20343022)
ITOI Keiichi Tohoku University, Graduate School of Information Sciences, Professor, 大学院・情報科学研究科, 教授 (60232427)
|
|---|
| Budget Amount *help |
¥2,900,000 (Direct Cost: ¥2,900,000)
Fiscal Year 2005: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 2004: ¥1,600,000 (Direct Cost: ¥1,600,000)
|
|---|
| Research Abstract |
In the insulin secretion of islet β-cells, the excitatory effect of norepinephrine (NE) linking to activation of phospholipase C (PLC) is known to be present, although that effect is masked by the inhibitory effect of NE through the pertussis toxin (PTX)-sensitive pathway. The present study was carried out to examined whether α_1-adrenoceptors were present in islet p-cells, and if present, what subtype of α_1-radrenoceptor was responsible for the excitatory action of NE.
In the PCR analysis for islets, three bands of 212 bp,300 bp and 304 bp, corresponding α_<1A>-,α_<1B>- and α_<1D>-adrenoceptors, were obtained. Compared with 212 and 300 bands, 304 band was weak. These results indicate that in islets, there are three subtypes of α_1-adrenoceptors, i.e.,α_<1A>,α_<1B> and α_<1D>, and that α_<1A> and α_<1B> are more prominent than α_<1D>. The PCR analysis also showed the presence of such α_1-adrenoceptor subtypes in rat liver tissues. In order to explore the localization of these receptor subtypes, we examined immunofluorescence using receptor antibodies. In the islets of slice preparations of rat pancreas, none of α_<1A>-,α_<1B>- or α_<1D>-adrenoceptors were seen. In addition, these receptor subtypes were also not observed in the area out of the islets. Furthermore, from the immunofluorescence study on liver slices, these three subtypes of α_1-adrenoceptors were not observed. These results indicate that although the messages for α_1-adrenoceptor subtypes (α_<1A>,α_<1B>,α_<1D>) are present in rat islets, their locarization is not confirmed because of the use of inadequate antibodies for the receptors.
|
