Effect of marijuana on the testis and accessory reproductive organs


Roth crude marijuana extract (CME) and THC produced a decrease in the weight of the reproductive organs of rats when given over a prolonged period of time and over several dosage ranges. The greatest effects were reported for high dosages (15 and 75 mg/kg orally daily for 77 days). Fujimoto et al. () showed significant reduction in ventral prostate, seminal vesicles, and epididymal weight, which was correlated with a decrease in plasma testosterone levels and was accompanied by a reduced number of sperm in the fluids of the epididymus. Treatment of the rats for only 5 days produced none of these changes. The effects of the cannabinoids appeared to be reversible, because there was a return to control levels of organ weights 30 days after cessation of drug treatment.

Similarly, Dixit and Lohiya () report that cannabis extract produced a marked reduction in the weights of seminal vesicles, ventral prostate, epididymus, and preputial glands of castrated adult male mice. Further, if cannabis extract was administered in combination with testosterone propionate, the growth stimulation produced by testosterone propionate alone was inhibited, indicating that cannabis extract may be antiandrogenic. However, there was no indication as to which compounds in the extract might produce the antiandrogenic effect. Vyas and Singh () report that cannabis administered to pigeons for 30, 60, or 90 days produced a significant decrease in the gross weight of the testis, decrease in the diameter of seminiferous tubules, degenerative changes in the seminiferous tubules, and a complete cessation of sperm production. Dixit et al. () also showed that CME (10 mg/kg I.P. for 10 days) produced degenerative changes in the testis of a toad including decreased Leydig cell nuclei, a reduction of RNA and protein contents in the testis, and an indication of reduced androgen production.

Purohit et al. () report that THC administered to hypophysectomized rats was able to block the stimulatory effect of human chorionic gonadotropin on ventral prostate and seminal vesicle weights but that serum testosterone and dihydroxytestosterone levels were unaffected. They concluded that THC must have both a direct tissue effect and an indirect hypothalamic-hypophyseal effect to reproduce the changes observed in the testis. Ghosh et al. () report that THC (10 mg/kg for 7 days) prevented the testosterone induced changes of DNA, RNA and protein content, acid phosphatase, and an isoenzyme variant of acid phosphatase in the ventral prostate tissues of adult castrated rats. They theorized that THC acted anti-androgenically directly at the level of the male accessory sex organs.

The reports in the literature of reduction in reproductive organ weights are accompanied by reports that show that the quality and quantity of sperm produced by the testis is affected by cannabinoids. Fosenkrantz and Hayden () report that rats exposed to single daily doses of Turkish marijuana smoke, containing .25% THC, exhibited seminiferous tubule degeneration with an interference with sperm maturation. Zimmerman et al. () have shown that treatment of mice for as few as 5 days with THC (5 mg/kg I.P.) or cannabidiol (CBD) (10 and 25 mg/kg I.P.) produced an increase in the number of abnormal sperm, including sperm which had an increased number of ring and chain translocations when the cells were evaluated 16 days after the last dose of cannabinoids. When calls were evaluated 35 days after the last of 5 consecutive days of cannabinoid treatment, among the abnormal sperm reported where those which had heads without hooks, banana shaped heads, amorphous heads, and folded heads. Huang et al. () reported that rats receiving .4 or 3 mg THC/kg as marijuana smoke for 75 days exhibited a decreased number of epididymal sperm, and an increased number of sperm with head to tail dissociations. These sperm changes were accanpanied by a decrease in testicle weight, a decrease in the weight of the seminal vesicles, and an increase in adrenal gland weight.

Dalterio et al. () treated male mice with THC, CBD, or CME (25 mg/kg) daily for 5 days. The mice were killed 50 to 60 days after cessation of drug treatment and meiotic chromosomes were prepared for microscopic examination from the testes. They reported that THC treated animals had a higher frequency of unpaired sex chromosomes at metaphase than did controls. Other chromosomal aberrations reported for cannabinoids include: ring and chain translocations, an increased incidence of aneupolidy, and a higher frequency of polyploidy. They also report that the cannabinoid treated males impregnated significantly fewer females, that the females successfully impregnated had a higher pre- and post-natal death rate and an increased percentage of pregnancies with fetal loss. The Fl male offspring, of these cannabinoid exposed males, who successfully impregnated females produced litters that had a higher incidence of developmental anomalies or that exhibited chromsomal rearrangements.

Several studies have been reported that may help to explain the reduced sperm production as well as the abnormalities that are seen in the semen after treatment of animals with various cannabinoids. Jakubovic and McGeer () studied the effects of THC and various water insoluble cannabinoids on metabolism in testicular slices and testicular cell suspensions. Cannabinoids (.1 mM) caused significant diminution in the amount of radioactivity that was incorporated into nucleic acids, lipids, and proteins in the testis slices. The cannabinoids inhibited the synthesis of labeled nucleotides and the incorporation of radioactive amino acids into proteins. They concluded that cannabinoid treatment produces a direct inhibitory effect of the cannabinoids on the kinases and/or polymerases involved in the RNA or DNA synthesis and that the inhibition of protein synthesis may be, in turn, a result of decreased chromosomal DNA, which could ultimately lead to alteration in spermatogenesis.

Jakubovic et al. (1979) also examined the effects of cannabinoids on testosterone and protein synthesis in rat testis Leydig cells in vitro. Various cannabinoids were added to the Leydig cell preparation at .15 mM concentration. It was found that HOG stimulated preparations incurred a 50% reduction in testosterone synthesis. However, the nonstimulated cultures had no effect on basal steroid-ogenesis even at cannabinoid concentrations of 15 mM. They concluded that cannabinoids at this high concentration may interfere directly with the Leydig cells to inhibit both protein synthesis and testosterone synthesis, and that the consequence of this inhibition might be affected spermatogenesis.

Several investigators have examined the effect that cannabinoids have on the enzymes of the testis in both in vivo and in vitro systems. There is evidence that cannabinoids affect the enzymes found in Sertoli cells in the seminiferous tubules which are important in sperm maturation. Schwartz et al. () have shown that treatment of rats with THC (2 mg/kg I.P. for 9 days) or with cannabidiol (2 mg/kg I.P. for 9 days), produced a decrease in both microsomal cytochrome P-450 Leydig cells of the testis (an enzyme which is involved in the biosynthesis of testosterone) and gamma-glutanlyl transpeptidase (a marker protein for Sertoli cells in the seminiferous tubules of the testis). Normal levels of cytochrome P-450 and gamma-glutamyl transpeptidase were restored when exogenous LH and FSH were supplied to the THC treated animals. These results indicate that some enzymatic defects caused by cannabinoid exposure may be prevented if normal levels of the gonadotropins are maintained and that cannabinoid effects on the testis might be due to defects of pituitary hormones rather than a direct action of the drugs on the testis. Goldstein et al. () reported that CBD (2 mg/kg/day, I.F.) and THC (2 mg/kg/day I.P.) depressed an esterase isozyrne of the rat Ieydig cells after 10 days of treatment with the cannabinoids. Also, Hubbard et al. () reported a reduced cholesterol esterase activity in cultured rat Leydig cells at a concentration of 16 mM. This enzyme hydrolyzes the cholesteryl esters of oleic, arachadonic, and palmitic acids.

A group of investigators () has examined the effect of various cannabinoids on the enzymes, involved in the synthesis of testosterone, that are located in the Leydig cells. An early study (Burstein 1978a) indicated that neither THC nor CBN (1 and 5 micrograms/ml) altered the transformation of either pregnenalone or progesterone to testosterone, a dose of cannabinoid that caused a 60% decrease in overall testosterone synthesis in vitro. They postulated that the cannabinoids either blocked the conversion of cholesterol to pregnenalone or somehow affected the availability of precursor-cholesterol. Burstein et al. () used isolated mouse Leydig cells as a model to examine the stepwise steroidogenic pathway for the site of action of THC and concluded that THC inhibition was effected at the release of precursor cholesterol from its ester storage. Shoupe et al. () showed that THC inhibited crude Leydig cell cholesterol esterase preparations with a mixed type of inhibition.

Cannabinoids are relatively insoluble in the aqueous medium used to culture testicular cells which raises the question of what the concentration of cannabinoids is in the culture media and how cannabinoids may affect other constituents of the culture media. A further complication is the fact that the actual tissue concentration in vivo may never approach the levels that were added to cultures to cause the results reported in vitro. At least one study () indicated that there was no selective concentration of radioactive a8-THc in the cells of the testis of mice administered the compound. Thus, some of the observations reported for alteration in protein synthesis and testosterone synthesis may be an artiface of an in vitro system and may not be representative of what was actually occurring in vivo.


Selections from the book: “Marijuana Effects on the Endocrine and Reproductive Systems”. Monique C. Braude, Ph.D., and Jacqueline P. Ludford, M.S., eds. A RAUS Review Report of animal studies and preclinical and clinical studies of effects of cannabinoids on human endocrine and reproductive functions. National Institute on Drug Abuse Research Monograph 44, 1984.