The [beta] adrenergic agonists attenuate fibroblast-mediated contraction of released collagen gels. Mio, Tadashi, Yuichi Adachi, Stefano Carnevali, Debra J. Romberger, John R. Spurzem, Stephen I. Rennard. Pulmonary and Critical Care Medicine Section, Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska
APStracts 2:0201L, 1995.
The effects of [beta]-adrenergic agonists on fibroblast mediated collagen gel contraction were investigated. [beta] agonists, isoproterenol and epinephrine, significantly attenuated fibroblast mediated gel contraction in a concentration-dependent manner, while [alpha]-agonist, norepinephrine had no effect. The biologically active form of isoproterenol, (-)-isoproterenol was 10-fold more effective than the optical isoform, (+)-isoproterenol. [beta] -antagonists, sotalol and propranolol, reversed the attenuation caused by 10-7M isoproterenol or epinephrine at the concentration of 10-7M or 10-6M, but the [alpha]- antagonist, phentolamine did not. However, [beta]1 or [beta]2 specificity of these effects is not clear. Isobutyl methylxanthine augmented the effect of isoproterenol and also prolonged the duration. Two reagents which are known to increase intracellular cyclic AMP, prostaglandin E2 and dibutyryl adenosine cyclic monophosphate attenuated gel contraction in a concentration -dependent manner. These data suggest that the fibroblast mediated collagen gel contraction can be modulated by [beta] adrenergic agonists, and that the effect depends on cyclic AMP.

Received 12 June 1995; accepted in final form 16 October 1995.
APS Manuscript Number L187-5.
Article publication pending Am. J. Physiol. (Lung Cell. Mol.
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 6 November 95