Role of insulin preincubation in the contractile reactivity of rat aortic rings
| Autor: | A, Rebolledo, V, Milesi, A G, Alvis, G J, Rinaldi, A O, Grassi de Gende |
|---|---|
| Rok vydání: | 1998 |
| Předmět: | |
| Zdroj: | Canadian Journal of Physiology and Pharmacology. 76:1066-1071 |
| ISSN: | 1205-7541 0008-4212 |
| DOI: | 10.1139/y98-132 |
| Popis: | Preincubation with physiological concentrations of insulin affects contractile reactivity of isolated smooth muscle cells. We studied the effects of insulin on intact aortic rings of Wistar rats preincubated 1-2 h with 240 pM (I1) and 960 pM (I2) insulin with and without NO synthesis inhibition by Nomega-nitro-L-arginine methyl ester (L-NAME). Resting force was tripled by 0.1 mM L-NAME in control (C) and I1 groups, but not in I2 groups. I1 treatment decreased the tachyphylaxis to two successive 1 µM arginine vasopressin (AVP) stimulations. Single contractions elicited by 1 µM AVP, 1 µM angiotensin II (AngII), or 0.01 µM endothelin (ET1) were not affected by insulin preincubation in either maximal force (Fmax) or relaxation times. L-NAME enhanced Fmax of AngII contractions by about 75% in C, 120% in I1, and 74% in I2 groups; accordingly, it augmented the final steady-state force in C and I1 but not in I2. Similarly, L-NAME increased Fmax (30-40%) of AVP and ET1 contractions in C and I1 groups but failed to do so in contractions of I2 group. Results obtained with 10 µM indomethacin suggest that this is due to insulin stimulation of prostacyclin effects.Key words: insulin, rat aorta, NO inhibition, arginine vasopressin, angiotensin II, endothelin 1, prostacyclin. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|