Reproductive Function In Mice Research Articles

Perinatal or adult exposure to cannabinoids alters male reproductive functions in mice

Oral administration of THC or CBN at a dose of 50 mg/kg body weight to pregnant and lactating female mice results in long-term effects on their male offspring, including: body weight regulation, pituitary-gonadal function, responsivity to exteroceptive stimuli from conspecifics and copulatory activity. Effects of perinatal exposure to cannabinoids on the male reproductive system did not become evident until after weaning (21 days of age). Male mice exposed to THC had reduced testes weight and elevated plasma LH levels during and after sexual maturation. In contrast, CBN-exposed males had reduced levels of testosterone (T) and LH during the prepubertal period and normal levels of these hormones after sexual maturation, although plasma FSH levels appeared reduced. In prepubertal males, production of androgen-dependent urinary pheromones, as assessed by uterine weight gain in cohabitant immature females, was not differentially affected by perinatal cannabinoid exposure. However, the pattern of body weight gain in the maturing males, the weights of the accessory reproductive organs and pituitary LH release were affected by the interaction of perinatal drug exposure and housing with an immature female. Plasma levels of T were elevated in all prepubertal males housed with an immature female for one week, whether or not the animals were previously exposed to cannabinoids. Copulatory behavior was reduced in adult males exposed to either THC or CBN during the perinatal period of sexual differentiation. Chronic treatment of adult males with 50 mg THC/kg body weight for 3 weeks increased testes weight and decresed the weights of the seminal vesicles. However, these effects were no longer evident after 7 weeks of THC treatment. The levels of copulatory activity displayed by the THC-exposed males were reduced after both 2.5 and 6 weeks of treatment. In contrast, oral administration of 50 mg/kg cannabinol for 3 weeks decreased testes and seminal vesicle weights and plasma T and LH levels. In addition, 2.5 weeks after the onset of CBN treatment, copulatory behavior was significantly suppressed. These findings indicate that both psychoactive and non-psychoactive constituents of mariuana affect pituitary-gonadal function in adult mice, and that the development of the male reproductive system is significantly altered in animals exposured to cannabinoids during critical periods of sexual differentiation. Moreover, some of the observed effects on male reproductive function and androgen-dependent behaviors may be secondary to alterations in the endocrine system produced by non-psychoactive and psychoactive components of marihuana.

Perinatal exposure to cannabinoids alters male reproductive function in mice.

Oral administration of delta 9-tetrahydrocannabinol or cannabinol to female mice late in pregnancy and during early lactation alters body weight regulation and pituitary-gonadal function and suppresses adult copulatory activity in their male offspring. These findings suggest that both psychoactive and nonpsychoactive constituents of marihuana can affect the development of male reproductive functions in mice.

Reproductive function in mice exposed to neonatal irradiation

Lifetime reproductive function following irradiation on the day of birth was studied in nine genotypes of mice obtained by crossing three inbred strains, BALB/Gw, K/Gw, and S/Gw, in all possible ways providing three inbred genotypes and six hybrid genotypes. The mice of each genotype were exposed to single whole-body 250 pkv X-ray dosages of 0R, 20R, 80R, 160R, and 320R. The experimental design gave an oppurtunity of relating radiation responses to the various genetic categories of offspring (inbreds versus hybrids, reciprocals, and so on). Mice were mated at 75 days of age to untreated mice of the Z/Gw strain. The incidence of sterility was increased appreciably only after exposures of 160R and above. Following 320R sterility was much higher in females than in males. The total number of litters and progeny also was affected adversely by neonatal irradiation. Females, in both cases, exhibited more severe effects than did the males. Compared to mice irradiated as 7 1 2 day old fetuses, neonatally-irradiated males females had decreased reproductive capacity and neonatally-irradiated males had increased reproductive capacity. No effects due to irradiation were noted in either the sex ratio of the progeny or the survival of progeny to 21 days of age. Heterosis due to strain crossing was observed in all measures of reproductive performance. Differential genotypic responses to neonatal irradiation were indicated by significant genotype x radiation interactions for reproductive responses.