title

تاثیر اپی تلیوم بر روی کاهش حساسیت گیرنده های آدرنرژیک بتای عضله صاف تراشه خوکچه هندی

بسکابادی, محمد حسین and اصلانی, محمدرضا (1386) تاثیر اپی تلیوم بر روی کاهش حساسیت گیرنده های آدرنرژیک بتای عضله صاف تراشه خوکچه هندی. Respiratory Physiology & Neurobiology ــ 156 (1). pp. 69-78. شاپا 1569-9048

[img]
Preview
Text
699kB

Official URL: http://www.sciencedirect.com/science/journal/15699...


Title

Influence of epithelium on beta-adrenoceptor desensitization of guinea pig tracheal smooth muscle

English Abstract

The effect of tissue incubation with a β2-agonist of denuded and intact epithelium trachea on the responsiveness to isoprenaline and β-receptor blocked by propranolol (CR-1) was examined in this study. We examined the effect of epithelium removal on the β-adrenoceptor desensitization resulting from incubation of guinea pig trachea in the β-adrenergic agonist isoprenaline (10 µM). Desensitization was measured as the change in EC50, the concentration of β-agonist that produced 50% relaxation of tracheal rings contracted with methacholine. As a second measure of desensitization, we measured the shift in EC50 resulting from incubation of tracheal rings with the β-adrenoceptor antagonist propranolol (20 nM), expressed as CR-1 ([post-propranolol EC50/baseline EC50]−1). Initially,we measured desensitization immediately after incubation in isoprenaline; subsequently, we repeated the protocol and allowed a 30 min rest between the end of incubation and the measurement. The sensitivity of denuded epithelium trachea to isoprenaline and (CR-1) was significantly higher than that of intact epithelium only in non-incubated preparations (p < 0.05 to p < 0.001). Incubation to isoprenaline caused a significant reduction in the tracheal response to isoprenaline in both the denuded groups (p < 0.005 for both cases) and intact epithelium groups (p < 0.05 for both cases). Incubation to isoprenaline also caused a significant reduction in (CR-1) value in both the denuded groups (p < 0.005 for group 2 and p < 0.001 for group 4) and intact epithelium only in group 1 (p < 0.05). However, the changes in EC50 due to tissue incubation with isoprenaline were significantly greater in denuded than intact epithelium trachea (p < 0.05 for all cases) and for CR-1 value only in groups 1 and 2 (p < 0.05). These results indicate decrease in both tracheal response to β-agonist (tolerance) and CR-1 (due to incubation of tissues with isoprenaline), which were greater in denuded epithelium groups.

Item Type:Article
زبان سند : انگلیسی
نویسنده مسئول :محمد حسین بسکابادی
نویسنده :محمدرضا اصلانی
Additional Information:IF:2.202 Indexed in: ISI, PubMed/Medline, Scopus
کلیدواژه ها (انگلیسی):Epithelium; Adrenergic receptors; Asthma; Tracheal responsiveness; Desensitization; Tolerance
Subjects:QT physiology
Divisions:Faculty of Medicine > Department of Basic Sciences > Department of physiology
ID Code:8785
Deposited By: Dr Mohammad Reza Aslani
Deposited On:10 Mar 1396 04:43
Last Modified:26 Jun 1402 14:34

Repository Staff Only: item control page

Document Downloads

More statistics for this item...