Further evidence for the selective disruption of intercellular communication by heptanol

• Published in: American journal of physiology. Heart and circulatory physiology 1999-06, Vol.276 (6), p.H1911-H1917
• Main Authors: Christ, G. J, Spektor, M, Brink, P. R, Barr, L
• Format: Article
• Language: English
• ISSN: 0363-6135; 1522-1539
• DOI: 10.1152/ajpheart.1999.276.6.h1911

1  Laboratory of Molecular and Integrative Urology, Department of Urology, Albert Einstein College of Medicine, Bronx 10461; 2  Department of Physiology and Biophysics, State University of New York at Stony Brook, Stony Brook, New York 11794; and 3  Department of Molecular and Integrative Physiology, University of Illinois, Urbana, Illinois 61801 The lack of selective gap junctional uncoupling agents has hampered evaluation of the contribution of intercellular communication to pharmacomechanical coupling and vascular contractility. Thus we further explored the utility and selectivity of heptanol as a gap junctional uncoupling agent in isolated rat aortic rings. Fifty-two aortic rings were obtained from 15 rats and were precontracted to ~75% of maximum with phenylephrine (PE). When contraction achieved steady state (~5 min), a single concentration of heptanol (200   µM) was added to each aortic ring at 1- to 3-min intervals for up to 42 min post-PE addition. At early time points (5-10 min after PE), heptanol elicited an ~50% loss of tension (i.e., relaxation). At subsequent time points post-PE, a gradual and time-dependent decrease in the magnitude of the heptanol-induced relaxation was observed until, after ~40 min, addition of heptanol was associated with little, if any, detectable relaxation. Linear regression analysis of the magnitude of the heptanol-induced relaxation vs. the square root of the elapsed time interval (from addition of PE) revealed a highly significant negative correlation ( P