AJP - Endocrinology and Metabolism, Vol 270, Issue 3 E438-E444, Copyright © 1996 by American Physiological Society

ARTICLES

Cocaine and exercise: temporal changes in plasma levels of catecholamines, lactate, glucose, and cocaine

D. H. Han, K. P. Kelly, G. W. Fellingham and R. K. Conlee
Department of Physical Education, Brigham Young University, Provo, Utah 84602, USA.

To determine the combined sympathoadrenal effects of cocaine and exercise in awake animals, rats were assigned to one of four treatment groups: saline-rest (SR), saline-exercise (SE), cocaine-rest (CR), and cocaine-exercise (CE). Venous blood samples from jugular catheters were obtained at -40, 0-4, 7, 10, 13, 16, 19, 26, and 36 min after intravenous injection of cocaine (5 mg/kg) or saline and the simultaneous onset of a 16-min treadmill run (26 m/min, 10% grade). CE increased plasma epinephrine (24.2 nM at 16 min), norepinephrine (28.0 nM at 10 min), and lactate (11.2 mM at 4 min) to levels 2-5 times greater than either treatment (SE and CR) alone (P<0.05) and 11-35 times higher that SR. Blood glucose values were significantly depressed in CE (-33% vs. SE) but increased in CR (+26% vs. SR). Plasma cocaine peaked < 2 min after injection in both CR and CE, and the peak was 69% higher in CE (P<0.05); however, the plasma elimination half-life (12-14 min) was not different. These results indicate that the combined effect of the two sympathoadrenal stimulants, exercise and cocaine, amplify the catecholamine responses to levels far greater than when each stimulant is used alone.

This article has been cited by other articles:

				R. K. Conlee, K. P. Kelly, E. O. Ojuka, and R. L. Hammer Cocaine and exercise: alpha -1 receptor blockade does not alter muscle glycogenolysis or blood lactacidosis J Appl Physiol, January 1, 2000; 88(1): 77 - 81. [Abstract] [Full Text] [PDF]