COCAINE EFFECTS ON PULSATILE SECRETION OF ACTH IN MEN

The effects of cocaine on pulsatile secretion of adrenocorticotropic h ormone (ACTH) in men were studied under controlled clinical research w ard conditions. Eight men with a Diagnostic and Statistical Manual of the American Psychiatric Association Version III, revised, diagnosis o f concurrent cocaine and opioid dependence provided their informed con sent for participation in this study. After an overnight fast, a chall enge dose of cocaine (30 mg i.v.) or placebo was administered under si ngle-blind conditions in a randomized order on 2 study days. Blood sam ples were collected at 2-min intervals for 76 min during base line and for an additional 76 min after i.v. administration of the challenge d ose. Peak plasma cocaine levels of 313.8 +/- 46.5 ng/ml were detected within 2 min after cocaine administration. The cluster analysis progra m originally described by Veldhuis and Johnson (1986) was used to char acterize ACTH pulsatile secretion (Iran-manesh et al., 1990). Acute co caine administration (30 mg i.v.) significantly increased ACTH mean pe ak amplitude (P < .05), mean percent increase in peak amplitude, (P <. 05), mean peak area (P < .04), total peak area (P < .04) and increment al peak height (P < .04). Mean ACTH valley levels (P < .02) and mean v alley nadir (P < .02) were also significantly increased after cocaine administration. We postulate that cocaine stimulates the release of co rticotropin releasing factor and that the cocaine-induced secretion of corticotropin releasing factor increases the amplitude of ACTH pulses , because ACTH pulse frequency was not altered by cocaine.