López-García Kenia, Mariscal-Tovar Silvia, Serrano-Meneses Martín Alejandro, Castelán Francisco, Martínez-Gómez Margarita, Jiménez-Estrada Ismael
Departamento Fisiología, Biofísica y Neurociencias, Centro de Investigación y Estudios Avanzados Instituto Politécnico Nacional, México, Mexico.
Departamento de Biología Celular y Fisiología, Unidad Periférica Tlaxcala, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Tlaxcala, Mexico.
Neurourol Urodyn. 2017 Aug;36(6):1456-1463. doi: 10.1002/nau.23143. Epub 2016 Sep 27.
We analyzed the effect of multiparity on the fiber type composition of two skeletal muscles involved in the maintenance of the micturition process, the pelvic pubococcygeus (Pc) and perineal bulbospongiosus (Bs) muscles in nulliparous and multiparous rabbits (Oryctolagus cuniculus).
We used the basic ATPase and NADH-TR techniques to identify and characterize slow, intermediate, and fast fiber types and glycolitic and oxidative fibers in muscles, respectively.
Pc muscles of multiparous rabbits present relatively high percentages of slow and intermediate fibers but a low percentage of fast fibers (P < 0.05) as compared to Pc muscles from nulliparous rabbits, while percentages of glycolytic and oxidative fibers were similar (P > 0.05). Bs muscles of multiparous rabbits had a higher proportion of intermediate and glycolytic fibers (P < 0.05) than muscles of nulliparous. Both, Pc and Bs muscles of nulliparous and multiparous rabbits contain slow fibers with similar large cross sectional area, but fast fibers in multiparous muscles showed small cross sectional area than in nulliparous.
Multiparity modified the fiber type composition of Pc and Bs muscles in female rabbits. We propose that the contractile force and the physiological role of both muscles during micturition are affected because of the observed changes in the relative composition of muscle fiber types.
我们分析了经产对未生育和经产兔（穴兔）排尿过程中涉及的两块骨骼肌，即盆腔耻骨尾骨肌（Pc）和会阴球海绵体肌（Bs）纤维类型组成的影响。
我们分别使用碱性ATP酶和NADH - TR技术来识别和表征肌肉中的慢肌纤维、中间肌纤维和快肌纤维类型以及糖酵解纤维和氧化纤维。
与未生育兔的Pc肌相比，经产兔的Pc肌中慢肌纤维和中间肌纤维的百分比相对较高，但快肌纤维的百分比较低（P < 0.05），而糖酵解纤维和氧化纤维的百分比相似（P > 0.05）。经产兔的Bs肌中中间肌纤维和糖酵解纤维的比例高于未生育兔（P < 0.05）。未生育和经产兔的Pc肌和Bs肌均含有横截面积相似的大型慢肌纤维，但经产肌中的快肌纤维横截面积比未生育肌中的小。
经产改变了雌性兔Pc肌和Bs肌的纤维类型组成。我们认为，由于观察到的肌纤维类型相对组成的变化，排尿过程中这两块肌肉的收缩力和生理作用受到影响。
