Srivastava A K, Anand-Srivastava M B
Biochem Pharmacol. 1985 Jun 1;34(11):2013-7. doi: 10.1016/0006-2952(85)90324-7.
Adenylate cyclase activity was investigated in myocardial sarcolemma, aorta particulate fractions, and liver plasma membranes from control and 5-day streptozotocin-induced diabetic rats. The basal adenylate cyclase activity was increased in heart sarcolemma from diabetic rats, whereas the extent of stimulation by glucagon, dopamine, isoproterenol, epinephrine, sodium fluoride and forskolin was decreased markedly. The decreased responsiveness was associated with a decrease in Vmax but not in the activation constant. In contrast, GTP stimulated adenylate cyclase in control and diabetic myocardial sarcolemma to the same extent. In addition, the basal adenylate cyclase activity was not altered significantly in aorta particulate fraction of liver plasma membranes from diabetic rats, but the stimulation of adenylate cyclase by catecholamines and forskolin (in the case of aorta) and by adenosine, glucagon, NaF and forskolin (in the case of liver) was diminished markedly. These data suggest that, in streptozotocin-induced diabetes, the responsiveness of adenylate cyclase to various hormones and agents (fluoride and forskolin) which act through receptor-independent mechanisms is decreased.
研究了对照大鼠和经链脲佐菌素诱导糖尿病5天的大鼠的心肌肌膜、主动脉微粒体部分及肝细胞膜中的腺苷酸环化酶活性。糖尿病大鼠心肌肌膜中的基础腺苷酸环化酶活性增加，而胰高血糖素、多巴胺、异丙肾上腺素、肾上腺素、氟化钠和福斯高林的刺激程度则显著降低。反应性降低与Vmax降低有关，但与活化常数无关。相比之下，GTP对对照大鼠和糖尿病大鼠心肌肌膜中腺苷酸环化酶的刺激程度相同。此外，糖尿病大鼠主动脉微粒体部分及肝细胞膜中的基础腺苷酸环化酶活性无显著改变，但儿茶酚胺和福斯高林（在主动脉的情况下）以及腺苷、胰高血糖素、氟化钠和福斯高林（在肝脏的情况下）对腺苷酸环化酶的刺激显著减弱。这些数据表明，在链脲佐菌素诱导的糖尿病中，腺苷酸环化酶对通过非受体依赖机制起作用的各种激素和试剂（氟化物和福斯高林）的反应性降低。
