Tests for induction of dominant-lethal mutations and heritable translocations with tetrahydrocannabinol in male mice

Abstract

The present study was prompted by the report in Science (Dalterio et al., 1982) that the major psychoactive component of marijuana, A9-tetrahy drocannabinol (THC), induced chromosome breakage in certain spermatogenic cells of mice. The evidence for this was derived from two experiments. In the first, males were given a single oral dose of THC (100 mg/kg) and killed 14 days later for cytogenetic analysis of diakinesis-metaphase I spermatocytes. The authors reported a significant increase over controls in the frequency of ring and chain quadrivalents. These multiplechromosome associations were presumably the result of reciprocal translocations induced in germ cells that were in the A4-intermediate spermatogonial stages (Oakberg, 1960) at the time of treatment. In the second study, male parents were given 50 mg/kg THC orally 3 times a week for 5 weeks and mated to untreated females from the 3rd through the 5th week of treatment. 2 male progeny with chromosomal rearrangements were found out of only 8 examined cytogenetically. Furthermore, while all male progeny from the control series suc-