Reproductive toxicity of marihuana smoke a three-generation study in female wistar rats

A three-generation study on the effects of marihuana smoke on female wistar rats was carried out. The mother/parent generation (Gm) and Gf(first generation) were each bred once to give rise to Gf and Gs(second generation) respectively. Reproductive indices studied included oestrous activity, fertility index,gestation of dams, gestation index, gestation survival index, number of pups born alive and pup birth weight. Reproductive toxicity was observed in this study as evidenced from the delayed onset of oestrous activity, frequently occurring oestrous cycles with shortened period of oestrous, reduced fertility index, premature parturition, diminished pup birth weight, reduced litter size as well as gestation survival index. This work shows that when marihuana is inhaled, neither oestrous activity nor ovarian activity is totally suppressed, but it is affected to a significant degree. Influence of marihuana smoke on excitability of uterine smooth muscle, transfer/utilization of nutrients and on hypothalamo-hypophyseal-ovarian axis was proposed to explain its reproductive toxicity. This study bears clinical implications and is useful in the counselling of female marihuana smokers (AU)

Long-term effects of marihuana smoke on uterine contractility and tumour development in rats

The present investigation considered the role of acute and chronic marihuana smoking, as well as crude extracts of marihuana (ME), on uterine contractions and tumour development. The contractions and the electrical activity were recorded on isolated superfused rats' uteri. Enhanced spontaneous activity and contractile responses were observed following exposure to marihuana smoke. Atropine failed to block contractile responses with ME following chronic smoke exposure. It is suggested that ME contains both contractile and relaxing properties. Chronic exposure to marihuana smoke resulted in appearance of various tumours in 50 percent of experimental animals. This study suggested far-reaching consequences on reproductive activity following chronic use of marihuana (AU)

Influence of marihuana smoking on female reproductive activity in albino rats

In recent years interest has mounted concerning the role of marihuana on reproductive physiology. Various reports in the literature suggest that marihuana influences female reproduction, and pose significant risks for the offspring. It has also been blamed for its embryotoxic/foetotoxic and teratogenic manifestations in animals. These reports are conflicting, confusing and sometimes contradictory. However, it could be conceived that marihuana use induces reproductive hazard. Moreover, marihuana has been used for facilitating childbirth and was tried in the management of menstrual disorders, but there is no evidence to establish the scientific basis for such claims. Despite the widespread use of marihuana, there are only a few studies available describing the effects of this drug in the female. This study was designed to investigate the potential effects of marihuana smoking on female reproductive process and foetal development. Albino rats were utilized for this experiment due to various practical advantages like availability, low cost, large number of animals per litter and brief gestational periods. Marihuana smoking has been employed to mimic human use and to restrict the use of heavy doses. Uterine smooth muscle contractility was studied to determine the influence of marihuana extract and the consequences of smoke exposure on uterine contractility. A chronic study, i.e. follow-up through two generations, was carried out since acute effects of marihuana may be insignificant and since continous maternal exposure could damage the foetus and chronic use could further deleterious effects. During this study a close watch was kept on the body weight to rule out the possible influence of undernutrition which may affect the reproductive function. Marihuana smoking has resulted in the reduction of body weight within the first week, but these animals later demonstrated a positive gain in weight and did not exhibit any obvious signs of undernutrition which may affect the reproductive function. Marihuana smoking has resulted in the reduction of body weight within the first week, but these animals later demonstrated a positive gain in weight and did not exhibit any obvious signs of undernutrition. A positive gain in body weight suggests development of tolerance following the smoking exposure. All the marihuana smoke-exposed rats exhibited delayed onset of oestrous activity but frequent oestrous cycles with a reduction in the duration of oestrous period. Such a change could interfere with fertility rate. Smoking also has resulted in suppression of ovalution. The fertility index (number of pregnant females/number of mated females) was significantly lowered. Other observations were shortened gestation period, low birth weight and diminished litter size. Reduction in fertility index and the gestation period may be the consequence of uterine stimulatory action of marihuana or suppressed ovarian activity. Low birth weight and reduction in the litter size could be due to probable embryotoxic effects of interference with transport mechanisms. Uterine contractile responses produced by crude aqueous marihuana extract (CAME) were significantly higher in smoke-exposed rats. CAME seems to depolarize the uterine smooth muscle, by activiting the muscarinic receptors. Chronic exposure to marihuana smoke seems to alter this response at receptor level. CAME is shown to possess both contractile and relaxing properties with dominant activity of the former. Chronic exposure to marihuana smoke resulted in appearance of tumours, like serous cystomata, follicular cysts, telengiectatic cysts, adenofibroma and adenocarcinoma in 50 percent of the experimental animals. The significance of this uterine stimulatory and tumorigenic potential of marihuana may have far-reaching consequences due to interference with foetal blood flow. Such a situation couls lead to deficient transport of O2, nutrients and toxic metabolities and precipitate not only foetal underdevelopment, but also reduction in litter size. Use of marihuana seems to influence the reproductive activity in females as evidences by delayed onset of oestrous activity, frequent oestrous cycles with reduced fertility index, shortened gestation periods, increased litter mortality, low birth weight, etc. This study clearly indicates that the marihuana smoke not only affects the maternal well-being but also jeopardizes the conditions under which the foetuses grow and develop (AU)