Full Text
(369 K)

Effects of Polymer Length and Cysteine Residues on Airway á-Adrenergic Receptor Function

M.M. Cloutier and L. Guernsey


Tannin, isolated from cotton bracts and implicated in the pathogenesis of byssinosis, inhibits isoproterenol-stimulated cAMP release from airway cells in part by decreasing cell surface -adrenergic receptor number and uncoupling the -adrenergic receptor from its stimulatory G-protein (Gs). We have hypothesized that tannin, because of its long polymer length and unusual monoflavanoid composition, interacts with the hydrophobic plasma membrane surface of the -adrenergic receptor and alters receptor binding and Gs coupling. In these studies, we demonstrate that decreased polymer length blocks tannin's inhibitory effects on chloride secretion, on cell surface -adrenergic receptor number and on isoproterenol-stimulated cAMP release. We also demonstrate that pretreatment with N-acetylcysteine, which interacts with cysteine residues, inhibits tannin's effects on isoproterenol-stimulated cAMP release. We conclude that polymer length and cysteine residues are essential for tannin's inhibitory effects on the airway epithelium.

Reprinted from Proceedings of the 1998 Beltwide Cotton Conferences pp. 181 - 184
©National Cotton Council, Memphis TN

[Main TOC] | [TOC] | [TOC by Section] | [Search] | [Help]
Previous Page [Previous] [Next] Next Page
Document last modified Sunday, Dec 6 1998