OBJECTIVE

To investigate the effect of sensory neuron-specific receptors (SNSRs) activation on the micturition reflex in rats.

MATERIALS AND METHODS

Continuous cystometrograms (CMG, 0.04ml/min) were performed in female Sprague-Dawley rats under urethane anesthesia. After stable micturition cycles were established, a selective rat SNSR1 agonist, bovine adrenal medulla 8–22 (BAM8-22), was administered intravenously or intrathecally in normal rats or rats pretreated with capsaicin 4 days before the experiments. Micturition parameters were recorded and compared before and after drug administration.

RESULTS

Intravenous administration of BAM8-22 (3 to 100 μg/kg) significantly increased intercontraction intervals in dose dependent fashion, but did not affect residual urine or baseline pressure at any doses tested. Intrathecal administration of BAM8-22 (0.01 to 0.3 μg) also increased intercontraction intervals in dose dependent fashion, but did not affect residual urine or baseline pressure at any doses tested. These inhibitory effects of intravenous (30 μg/kg) or intrathecal (0.3 μg) administration of BAM8-22 were still observed after capsaicin pretreatment.

CONCLUSION

These results indicate that in urethane-anesthetized rats activation of SNSRs can inhibit the micturition reflex via the pathways independent of capsaicin sensitive C-fibers. Thus SNSRs could be a potential target for the treatment of bladder dysfunction such as overactive bladder.

Purpose

The association of cytochrome P450 aromatase gene CYP19(TTTA)n polymorphism with ovarian response to FSH stimulation was explored.

Methods

Three hundred women undergoing medically assisted reproduction and 300 women with at least one spontaneous pregnancy participated in the study. CYP19(TTTA)n polymorphism was genotyped, while serum hormones were determined. During oocyte retrieval, the follicular size, the follicle and oocyte numbers were recorded.

Results

Six CYP19(TTTA)n alleles with 7 to 12 repeats were revealed. Women homozygous for long CYP19(TTTA)n alleles presented with lower serum FSH levels at the third day of the menstrual cycle (p < 0.001) and higher large follicle numbers (p < 0.01), compared to women homozygous for short CYP19(TTTA)n alleles. The CYP19(TTTA)7 allele was associated with higher serum FSH levels (p < 0.003), with lower total follicle (p < 0.02) and large follicle numbers (p < 0.03), while CYP19(TTTA)7 allele-carriers presented more frequently with small follicles than CYP19(TTTA)7 allele-non carriers (p < 0.01).

Conclusions

CYP19 genetic variants were associated with ovarian reserve and response to standard gonadotrophin stimulation of women undergoing in vitro fertilization.

To investigate why the development of a completely circular striated sphincter is so rare, we examined histological sections of 11 female and 11 male mid-term human fetuses. In male fetuses, the striated muscle initially extended in the frontal, rather than in the horizontal plane. However, a knee-like portion was absent in the female fetal urethra because, on the inferior side of the vaginal end, a wide groove for the future vestibule opened inferiorly. Accordingly, it was difficult for the developing striated muscle to surround the groove, even though there was not a great difference in width or thickness between the female vestibule and the male urethra. The development of a completely circular striated sphincter seems to be impossible in females because of interruption of the frontal plane by the groove-like vestibule. However, we cannot rule out the possibility that before descent of the vagina, the urethral striated muscle extends posteriorly.