Abstract
Tolerance to δ 9-tetrahydrocannabinol (THC) was examined in 96 rats, 48 of which were immature (30 days) at the start of the study and 48 of which were adults (90 days). For both age groups the treatments consisted of three phases and during each phase, lasting at least twenty days, animals received either THC or a control drug. Behavioral measures were taken during the third phase and, at the end of the study, weights of various organs were determined. The results revealed that degrees of tolerance exist and that the age of the subject at the time of initial chronic THC experience interacts with the later development of tolerance to the drug. In addition, heart and brain weights were reduced in those subjects receiving chronic THC injections while immature.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Bueno, O. F. A., Carlini, E. A.: Dissociation of learning in marihuana tolerant rats. Psychopharmacologia (Berl.) 25, 49–56 (1972)
Campbell, A. M. G., Evans, M., Thompson, J. L. G., Williams, M. J.: Cerebral atrophy in young cannabis smokers. Lancet 1971 II, 1219–1224
Carlini, E. A.: Tolerance to chronic administration of Cannabis sativa (marihuana) in rats. Pharmacology 1, 135–142 (1968)
Cooley, W. W., Lohnes, P. R.: Multivariate Data Analysis New York: John Wiley and Sons 1971
Kalant, A., LeBlanc, A. E., Gibbons, R. J.: Tolerance to and dependence on, some non-opiate psychotiopic drugs. Pharmacol. Rev. 23, 135–191 (1971)
Kirk, E. R.: Experimental design: procedures for the behavioral sciences California: Brooks and Cole, 1968
Konig, J. F. R., Klippel, R. A.: The rat brain. Baltimore: Williams and Wilkims 1963
Lipparini, F., Scotti Decarolis, A., Longo, V. G.: A neuropharmacological investigation of some trans-tetrahydrocannabinol derivatives. Physiol. Behav. 4, 527–532 (1969)
Manning, F. J., McDonough, J. H., Jr., Elsmore, T. F., Saller, C., Sodetz, F. J.: Inhibition of normal growth by chronic administration of δ 9-tetrahydrocannabinol. Science 169, 501–503 (1970)
McMillan, D. E., Dewey, W. L., Harris, L. S.: Characteristics of tetrahydrocannabinol tolerance. Ann. N.Y. Acad. Sci. 191, 83–99 (1971)
Mechoulam, R.: Marihuana Chemistry. Science 168, 1159–1160 (1970)
Potvin, R. J., Fried, P. A.: Acute and chronic effects on rats of (−)δ 9-trans-tetrahydrocannabinol on unlearned motor tasks. Psychopharmacologia (Berl.) 26, 369–378 (1972)
Scott, J. P.,: Critical periods in behavioral development. Science 138, 949–958 (1962)
Author information
Authors and Affiliations
Additional information
This article is based upon a Master's thesis submitted by the first author in partial fulfillment of the requirements for the Master's degree at Carleton University.
This work, portions of which were presented at NATO symposium on Drugs, Sleep, and Performance in September, 1972, was partially supported by a Medical Research Council grant to the second author.
We are indebted to J. Tombaugh and E. Minch for assistance with the statistical analysis and the Ontario Department of Agriculture and Food for performing the pathological tests.
Rights and permissions
About this article
Cite this article
Barnes, C., Fried, P.A. Tolerance to δ9-THC in adult rats with differential δ9-THC exposure when immature or during early adulthood. Psychopharmacologia 34, 181–190 (1974). https://doi.org/10.1007/BF00421959
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF00421959