摘要
目的:研究M_3型胆碱能受体与配体的结合可否导致钙离子/钙调素依赖性蛋白激酶Ⅱ(CaMkinaseⅡ)的激活.方法:用胶原水解酶法分离大鼠胰腺腺泡,并检测乌拉胆碱(Bet)刺激腺泡细胞前后自身磷酸化型的CaM kinaseⅡ的活性.结果:Bet对该激酶的活化是时间(5-300 s)和浓度(0.0001-1 mmol·L^(-1))依赖性的,并可被阿托品所阻断.Bet 100 μmol·L^(-1)在5 s内可以引起CaM kinaseⅡ的激活(非钙离子/钙调素依赖性激酶活性从4.5±0.3,增加到8.9±1.3);辛卡利特1 μmol·L^(-1)也导致该酶的激活(增加到12.9±0.5),而血管活性肠肽1 μmol·L^(-1)无作用.结论:CaM kinaseⅡ在消化酶的分泌中,尤其是消化酶分泌的始发期,起着重要作用.
AIM: To study whether M3 receptor occupation would lead to activation of calcium/calmodulin-dependent protein kinase Ⅱ (CaM kinase Ⅱ ). METHODS: In this study, we isolated rat pancreatic acini by collagenase digestion; measured the Ca2+/calmodulin-independent activity of autophosphorylated form of the CaM kinase Ⅱ both before and after stimulation of the acini with muscarinic secretagogue bethanechol ( Bet ). RESULTS: Bet stimulated the activation of, or generation of Ca2+ -independent activity of, this kinase, in a concentration (0.0001 - 1 mmol·L-1) and time (5 - 300 s)-dependent manner; with Bet of 100 μmol ·L-1, Ca2+-independent activity increased from an unstimulated level of 4.5 ± 0.3 (n = 4) to 8.9±1.3 (n =4, P<0.05) at 5 s. Another Ca2+ mobilizing secretagogue cholecysto-kinin (CCK) also activated the kinase; at 1 μmol ·L-1, CCK increased Ca2+-independent kinase activity to 12.9 ±0.5 ( n = 6, P < 0.05). Vasoactive intestinal peptide (VEP) at 1 μmol·L-1 did not produce significant Ca2+ -independent kinase activity (from control 3.90 ±0.28 to 4.53 ± 0.47, n = 6, P>0.05). Atropine completely blocked Bet activation of the kinase. CONCLUSION: CaM kinase Ⅱ plays a pivotal role in digestive enzyme secretion, especially during the initial phase of amylase secretion.
出处
《中国药理学报》
CSCD
1997年第3期255-258,共4页
Acta Pharmacologica Sinica
关键词
钙
钙调素
胰岛
腺泡细胞
蛋白激酶
胆碱能
激活
atropine
bethanechol
calcium
calmodulin
islets of Langerhans
protein kinases
sincalide
vasoactive intestinal peptide
