© 1991 Oxford University Press
research-article |
Chronic Marijuana Smoke Exposure in the Rhesus Monkey I. Plasma Cannabinoid and Blood Carboxyhemoglobin Concentrations and Clinical Chemistry Parameters1
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*Pharmacodynamic Branch, Division of Reproductive and Development Toxicology, National Center for Toxicological Research Jefferson, Arkansas 72079-3502
Arkansas Children's Hospital Little Rock, Arkansas 72205
Department of Pharmacology and Toxicology
§Department of Pediatrics
|Department of Physiology and Biophysics
¶Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences Little Rock, Arkansas 72205
Received December 3, 1990; accepted February 26, 1991
Chronic Marijuana Smoke Exposure in the Rhesus Monkey I. Plasma Cannabinoid and Blood Carbxyhemoglobin Concentrations and Clinical Chemistry Parameters SLIKKER, W., JR., PAULE, M. G., ALI, S. F., SCALLET, A. C., AND BAILEY, J. R (1991). Fundam. Appl Toxicol 17, 321–334. This report is the first in a series about a large multidisciplinary study designed to determine whether chronic marijuana (MJ) smoke exposure results in residual behavioral and/or neuropathological alterations in the rhesus monkey. Prior to the initiation of a year of chronic MJ smoke exposure, 64 periadolescent male rhesus monkeys were trained for 1 year to perform five operant behavioral tasks and then divided, according to their performance in these tasks, into four exposure groups (n=15–16/group): (1) a high dose (HI) group, exposed 7 days/week to the smoke of one standard MJ cigarette; (2) a low d m (LO) group, exposed on weekend days only to the smoke of a standard MJ cigarate; (3) an extracted MJ cigarette (EX) group, exposed 7 days/week to the smoke of one ethanol-extracted MJ cigarette; and (4) a sham group (SH), exposed 7 days/week to sham exposure conditions. Daily exposures for 1 year were accomplished using a mask that covered the subjects' nose and mouth. Average body weights (initially 3.7±0.5 kg, mean±SD) and rates of weight gain (approximately 0.1 kg/month) were the same for all groups throughout the entire experiment. During the first week of expsure, plasma concentrations of 
-9-tetrahydrocannabinol and 11-nor-9-carboxy-THC in the HI group were 59±7 (mean±SE) and 5.5±1.5 ng/ml, respectively, 45 min after MJ smoke administration and did not change significantly at similar times after exposure throughout the remainder of the year. Whole blood carboxyhemoglobin levels increased to approximately 13% 1 min after expsure to smoke in either the MJ or the EX groups. Comparison of blood chemistry and hematology values before, during, and after exposure indicated no differences for most parameters. During exposure, lymphocytes, alkaline phosphatase and 
-glutamyl transferase were depressed in the HI group compared to in the SH group. During exposure, aspartate aminotransferase was elevatd for both the HI and EX groups, suggesting a general effect of smoke exposure. Because these effects were transient and remained within the range of reported normal values, these data indicate that long-term, experimental experimental exposure to MJ smoke is feasible and does not compromise the general health of the rhesus monkey.