Assessment of myoelectrical signal parameters in estrogen, progesterone, and human chorionic gonadotropin administered in nonpregnant rat myometrium after ovariectomy

Relation between uterine morphology and severity of primary dysmenorrhea

Objective

This study aimed to evaluate whether uterine dimensions including uterine volume, uterine shape, uterine length, cervix length, and cervix thickness measurements have a role in the severity of primary dysmenorrhea in virgin girls.

Materials and Methods

Enrollment included 90 virgin girls suffering from primary dysmenorrhea. The girls were divided into three groups according to the severity of dysmenorrhea, which was determined by the visual analog scale (VAS). Patients with VAS scores of 8-10 comprised the severe primary dysmenorrhea group (n=30), 4-7 the moderate primary dysmenorrhea group (n=30), and 1-3 the mild primary dysmenorrhea group (n=30). Uterine characteristics including uterine volume, uterine shape, uterine length, cervix length, and cervix thickness were measured by a high-resolution four-dimensional ultrasound device with real-time capacity. They were recorded to determine if they can be predictors of dysmenorrhea severity.

Results

Girls with severe primary dysmenorrhea were more likely to complain of midline pain as opposed to mild and moderate cases with lateral or diffuse pain. None of the uterine characteristics on ultrasonography examination were significant for predicting the severity of primary dysmenorrhea. There were no significant positive correlations between the dysmenorrhea severity and uterine corpus length, cervix length, and uterine volume degree. Any combination of the measured uterine features was not predictive for determining the severity of dysmenorrhea.

Conclusion

Ultrasonographic measurements of uterine dimensions in virgins have low accuracy for predicting the severity of pain in primary dysmenorrhea.

Effects of highly purified urinary FSH and human menopausal FSH on uterine myoelectrical dynamics

The aim of the study was to investigate the effects of urinary follicle-stimulating hormone (FSH) compounds on the electrical activity of myometrium using signal-processing techniques. Thirty animals were involved in the experiment. After two successive normal estrous cycles, 15 of these animals were put into three equal subgroups. Group 1 was the control; animals were given solvent. Groups 2 and 3 were treated with Urofollitropin and Menotropin, respectively. The other 15 animals were ovariectomized and subjected to the same protocol. Their uterine myoelectrical signals were recorded over a period of at least 3 min at a sampling frequency of 500 Hz, and analyzed through software assisted signal processing. The results show the power and some characteristic spectral components of myoelectrical signal were differentially reduced with the administration of highly purified urinary FSH and human menopausal FSH but significant differences were not detected between their histology. In conclusion, uterine myoelectrical signals change with administration of urinary FSH preparations. Human menopausal FSH and more precisely highly purified FSH suppress the spectral components and modify the power of the myoelectrical signals which provides uterine quiescence.

Neuroactive steroids inhibit spinal reflex potentiation by selectively enhancing specific spinal GABA(A) receptor subtypes

Recently, we demonstrated a spinal GABA(A) receptor (GABA(A)R)-dependent inhibition on the induction of repetitive stimulation-induced spinal reflex potentiation. However, it remains unclear whether steroid hormones modulate such an inhibition. Here, we show that progesterone is capable of producing GABA(A)Rs-dependent inhibition of the induction of spinal reflex potentiation by actions through neurosteroid metabolites. Progesterone (5mg/kg, twice daily for 4 days) up-regulates the expression of GABA(A)R alpha2, alpha3, alpha4 and delta subunits, and is associated with attenuated repetitive stimulation-induced spinal reflex activity in ovariectomized rats. These changes were blocked by finasteride (50mg/kg, twice daily), an antagonist of neurosteroid synthesis from progesterone, but not by the progesterone receptor antagonist, RU486 (100mg/kg, twice daily). The induction of spinal reflex potentiation was attenuated after a short (30 min) intrathecal treatment with the neurosteroids, allopregnanolone (ALLOP, 10 microM, 10 microL) and 3 alpha,5 alpha-tetrahydrodeoxycorticosterone (THDOC, 10 microM, 10 microL). Acute intrathecal administration of the GABA(A)R antagonist, bicuculline (10 microM, 10 microL) reversed the inhibition produced by progesterone, THDOC and allopregnanolone. These results imply that progesterone-mediated effects on GABA(A)R expression and neural inhibition are regulated by neurosteroids synthesis rather than progesterone receptor activation.

Spectrotemporal changes in electrical activity of myometrium due to recombinant follicle-stimulating hormone preparations follitropin alfa and beta

OBJECTIVE

To investigate the effects of follitropin alfa and beta on the myoelectrical activity of rat myometrium using signal-processing techniques.

DESIGN

Prospective, placebo-controlled study.

SETTING

Animal and pharmacology laboratory at Inonu University.

ANIMAL(S)

Forty-five female Wistar albino rats.

INTERVENTION(S)

Thirty of 45 animals involved in the experiment were registered as the superovulation group. After two successive normal estrous cycles, these animals were put into three equal subgroups. Group 1 was the control; animals were given 0.9% saline. Groups 2 and 3 were treated with follitropin alfa (Gonal-f) and follitropin beta (Puregon), respectively. The other 15 animals were ovariectomized (OVX) and subjected to the same protocol. The uterine myoelectrical signals were recorded and analyzed using a Matlab environment.

MAIN OUTCOME MEASURE(S)

Power/second, variance, and the effects of recombinant human follicle-stimulating hormone (FSH) on myoelectrical signals were assessed through temporal, spectral, and joint time-frequency analysis. The uterine endometrium and ovarian morphology were also assessed concerning primary follicles, antral follicles, and corpora lutea.

RESULT(S)

The power and some characteristic spectral components of myoelectrical signal were reduced with the administration of follitropin alfa and beta. No statistically significant difference was detected between endometrial and ovarian histology of the rats treated with these follitropins.

CONCLUSION(S)

Uterine myoelectrical signals change with administration of recombinant human FSH preparations. Follitropin beta and, more precisely, follitropin alfa suppress the spectral components and power of the myoelectrical signals, which provides uterine quiescence.