التفاصيل البيبلوغرافية
| العنوان: |
Impairment of α1-adrenoceptor-mediated contractile activity in caudal arterial smooth muscle from Type 2 diabetic Goto-Kakizaki rats. |
| المؤلفون: |
Mita, Mitsuo1, Kuramoto, Takuto1, Ito, Kazushi1, Toguchi-Senrui, Natsuko1, Hishinuma, Shigeru1, Walsh, Michael P2, Shoji, Masaru1 |
| المصدر: |
Clinical & Experimental Pharmacology & Physiology. Mar2010, Vol. 37 Issue 3, p350-357. 8p. 1 Chart, 6 Graphs. |
| مصطلحات موضوعية: |
*TYPE 2 diabetes, *ANIMAL models of diabetes, *COMPARATIVE studies, *ALPHA adrenoceptors, *VASCULAR smooth muscle, *MUSCLE contraction, *MESSENGER RNA, *GENE expression, *POLYMERASE chain reaction |
| مستخلص: |
1. In the present study, we compared the responsiveness of de-endothelialized caudal artery smooth muscle strips, isolated from Type 2 diabetic Goto-Kakizaki (GK) and normal Wistar rats, to α1-adrenoceptor stimulation (cirazoline) and membrane depolarization (K+). 2. The contractile and myosin 20 kDa light chain (LC20) phosphorylation responses to 0.3 μmol/L cirazoline of caudal artery strips isolated from 12-week-old GK rats were significantly reduced compared with those of age-matched Wistar rats, whereas the contractile and LC20 phosphorylation responses to 60 mmol/L K+ were unaltered. 3. Stimulation of fura 2-AM-loaded strips from GK rats with 0.3 μmol/L cirazoline induced a significantly smaller rise in [Ca2+]i (by ∼20%) compared with that in strips from Wistar rats, whereas comparable Ca2+ transients were evoked by K+ in both. 4. Using quantitative polymerase chain reaction, no significant differences were detected in the mRNA expression of α1A-, α1B- and α1D-adrenoceptor subtypes between GK and Wistar rats. 5. Cirazoline (1 μmol/L)- and caffeine (20 mmol/L)-induced contractions in the absence of extracellular Ca2+ were unaltered in GK rats, suggesting that the release of Ca2+ from the sarcoplasmic reticulum in response to cirazoline does not differ between GK and Wistar rats. 6. The results of the present study suggest that Ca2+ entry from the extracellular space via α1-adrenoceptor-activated, Ca2+-permeable channels, but not via membrane depolarization and voltage-gated L-type Ca2+ channels, is impaired in caudal artery smooth muscle of GK rats. [ABSTRACT FROM AUTHOR] |
| قاعدة البيانات: |
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