Environmental temperature and cryptorchidism: effects on pregnenolone-sulfatase of mice testicular tissue.

This study examined the capacity of abdominal organs, such as the scrotal testis, exposed to environmental temperature to hydrolyze pregnenolone sulfate. The cryptorchid state of exposure to 34 degrees C during 14 days decreased testis weight by 38 and 23%. But the enzymatic activity (nanomoles of free steroid/testis) was significantly higher (p < .05) compared with the control. Moreover, a rise in the environmental temperature combined with cryptorchidism in mice, two conditions that induced testicular damage, has been related to the elaboration of factors capable of modifying, through paracrine mechanism, the androgen biosynthesis. The presence of this factor could lead to an increase in the hydrolysis of pregnenolone sulfate, but as for cryptorchidism or high environmental temperature exposure, when cryptorchid mice were exposed to temperatures of 34 degrees C an apparent synergism of both conditions produced a decrease of 66% in testis weight. It would appear that the steroid sulfatase is predominantly located in the interstitial epithelium. This study suggests that cryptorchidism and hyperthermia damage the tubular epithelium by different mechanisms.

The sensitivity of rat uterus to serotonin in vitro is a late estrogenic response.

This study was designed to further characterize the sensitivity to serotonin of the isolated rat uterus. The contractile response to serotonin induced by the administration of estradiol was increased depending on the duration of estradiol-treatment, reaching the maximal contractility when ovariectomized rats were treated for 48 hours. Pretreatment with actinomycin D 1 hour before estrogen administration completely blocked estrogen-induced uterine sensitivity to serotonin. These results indicate that the sensitivity of rat uterus to serotonin in vitro induced by estradiol is a response occurring in the late phase and mediated by genomic activation. Following estradiol-administration uterine sensitivity to serotonin was similar in ovariectomized and ovariectomized-hypophysectomized rats, suggesting that in this response a pituitary factor is not required. The contractile responses to acetylcholine and oxytocin were not modified by estradiol; thus, estrogens induced specifically uterine sensitivity to serotonin. The present in vitro studies using pelanserin, a potent S2-antagonist, show that serotonin induced contractions in the rat uterus are mediated by interaction with S2-receptors, since pelanserin inhibited not-competitively the contractile response to serotonin.

The zoapatle. XV. Activity of 16 alpha-hydroxy-ent-kauran-19-oic acid isolated from Montanoa hibiscifolia, and its methyl ester on rat and guinea pig uterus.

16 alpha-Hydroxy-ent-kauran-19-oic acid was isolated from Montanoa hibiscifolia. The effects of this acid and its methyl ester on the contractile activity of rat and guinea pig uterine horns were studied. Both inhibited spontaneous, oxytocin-induced and potassium-induced contractile activities. The inhibitory effect produced by the methyl ester was greater than that observed with the acid. The methyl ester was 2-5 times more potent than the acid upon spontaneous and potassium-induced contractions and 11-15 times more potent than the acid upon the contractile activity of uterine smooth muscle induced by oxytocin. Such effects were observed using bath concentrations of 6, 15, 30 and 60 microM of each compound.