Rhode López-Juárez1,2, René Zempoalteca2, Dora Luz Corona-Quintanilla2, Ismael Jiménez-Estrada3, Francisco Castelán2,4, Margarita Martínez-Gómez2,4. 1. Doctorado en Ciencias Biológicas, Universidad Autónoma de Tlaxcala, Tlaxcala, México. 2. Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, Tlaxcala, México. 3. Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de México, México. 4. Instituto de Investigaciones Biomédicas, Departamento de Biología Celular y Fisiología, Unidad Foránea Tlaxcala, Universidad Nacional Autónoma de México, Tlaxcala, México.
Abstract
AIMS: To characterize the contractile properties of the bulbospongiosus (Bsm), isquiocavernosus (Ism), and pubococcygeus muscles (Pcm), and their involvement in the genesis of vaginal pressure in nulliparous and multiparous rabbits. METHODS: Age-matched nulliparous and multiparous rabbits were used to record the isometric contractile responses of each muscle as well as the intravaginal pressure evoked by single square electrical pulses and stimulation trains of ascending frequency. To establish significant differences between groups, two-tail unpaired Student t tests were carried out. The linear correlation between intravaginal pressure and muscle contractile force was analyzed with Pearson correlation tests. For all cases, a P ≤ 0.05 was set as statistically significant. RESULTS: Multiparity decreased the contractile force of Bsm and Ism generated by high-frequency stimulation trains. The normalized force of the Pcm increased when evoked at 1, 4, and 10 Hz while this decreased at higher frequencies (20, 50, and 100 Hz). The contraction of both Bsm and Ism raised particularly the pressure on the perineal vagina while that of the Pcm increased the pressure in the pelvic vagina. Such a functional segregation is still present in multiparous rabbits albeit it was modified. CONCLUSIONS: Multiparity induces changes in the contractile responses of Bsm, Ism, and Pcm, which alterates the vaginal pressure.
AIMS: To characterize the contractile properties of the bulbospongiosus (Bsm), isquiocavernosus (Ism), and pubococcygeus muscles (Pcm), and their involvement in the genesis of vaginal pressure in nulliparous and multiparous rabbits. METHODS: Age-matched nulliparous and multiparous rabbits were used to record the isometric contractile responses of each muscle as well as the intravaginal pressure evoked by single square electrical pulses and stimulation trains of ascending frequency. To establish significant differences between groups, two-tail unpaired Student t tests were carried out. The linear correlation between intravaginal pressure and muscle contractile force was analyzed with Pearson correlation tests. For all cases, a P ≤ 0.05 was set as statistically significant. RESULTS: Multiparity decreased the contractile force of Bsm and Ism generated by high-frequency stimulation trains. The normalized force of the Pcm increased when evoked at 1, 4, and 10 Hz while this decreased at higher frequencies (20, 50, and 100 Hz). The contraction of both Bsm and Ism raised particularly the pressure on the perineal vagina while that of the Pcm increased the pressure in the pelvic vagina. Such a functional segregation is still present in multiparous rabbits albeit it was modified. CONCLUSIONS: Multiparity induces changes in the contractile responses of Bsm, Ism, and Pcm, which alterates the vaginal pressure.
Authors: Margarita Martínez-Gómez; Mario I Romero-Ortega; Ana G Hernandez-Reynoso; Dora L Corona-Quintanilla; Kenia López-García; Ana A Horbovetz; Francisco Castelán; Philippe Zimmern Journal: Sci Rep Date: 2021-05-19 Impact factor: 4.379
Authors: Dora Luz Corona-Quintanilla; Rhode López-Juárez; Pablo Pacheco; Mario I Romero-Ortega; Francisco Castelán; Margarita Martínez-Gómez Journal: Neurourol Urodyn Date: 2019-10-02 Impact factor: 2.367
Authors: Francisco Castelán; Kenia López-García; Suelem Moreno-Pérez; René Zempoalteca; Dora L Corona-Quintanilla; Mario I Romero-Ortega; Ismael Jiménez-Estrada; Margarita Martínez-Gómez Journal: Brain Behav Date: 2018-09-21 Impact factor: 2.708