AJP - Heart and Circulatory Physiology, Vol 253, Issue 3 548-H555, Copyright © 1987 by American Physiological Society

ARTICLES

Effects of aminophylline on behaviorally induced coronary blood flow increases

G. E. Billman

It has been proposed that adenosine is a metabolic vasodilator that matches myocardial oxygen supply to demand by regulating coronary blood flow. In the present study, the adenosine antagonist aminophylline (Am) was used to evaluate the role adenosine plays in the coronary blood flow increase elicited by a controlled aversive stress, namely, classical aversive conditioning (a 30-s tone reinforced with a 1-s shock). Fifteen mongrel dogs were chronically instrumented to measure left circumflex coronary blood flow (CBF), left ventricular pressure (LVP), and heart rate. Am significantly (P greater than 0.01) attenuated the CBF response to the aversive stress without affecting the prestress levels (pre-Am control 40.9 +/- 2.4, peak 64.6 +/- 3.3 ml/min; post-Am control 41.7 +/- 2.2, peak 55.0 +/- 2.5 ml/min). The maximal CBF increase was reduced by 38.9 +/- 6.7% when compared with the control (no drug) condition. In a similar manner, neither heart rate nor LVP was affected by Am. However, Am significantly increased prestress level of first derivative of left ventricular pressure with reference to time [LV dP/dt] (pre-Am control 3,793.5 +/- 289.8 and Am 4,599.6 +/- 331.2 mmHg/s, respectively). These data suggest that adenosine contributes significantly to the regulation of CBF during a controlled emotional stress.

This article has been cited by other articles:

				G. E. Billman, H. C. Englert, and B. A. Schölkens HMR 1883, a Novel Cardioselective Inhibitor of the ATP-Sensitive Potassium Channel. Part II: Effects on Susceptibility to Ventricular Fibrillation Induced by Myocardial Ischemia in Conscious Dogs J. Pharmacol. Exp. Ther., September 1, 1998; 286(3): 1465 - 1473. [Abstract] [Full Text]