The Effects of Castration and Hormone Replacement on the Cross‐Sectional Area of Pubococcygeus Muscle Fibers in the Female Rat

Lara-García, Miguel; Alvarado, Mayvi; Cuevas, Estela; Cortés-Sol, Albertina; Dominguez, Andres; Tovar, Anibal; Pacheco, Pablo

doi:10.1002/ar.21414

Cited by 12 publications

(6 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…17 Serum estradiol levels and the age of rabbits could explain the CSA response herein and in the previous study. Otherwise, findings herein, and from other rat studies, 27,28 confirm estrogen can differentially affect individual PFM. Although, in rats, the Pcm myofiber CSA seems more responsive to estrogens that induce a CSA reduction.…”

Section: Discussionsupporting

confidence: 63%

See 1 more Smart Citation

Estrogens influence differentially on the pelvic floor muscles activation at somatovisceral reflexes involved in micturition of rabbits

et al. 2021

View full text Add to dashboard Cite

Objective: To determine the estrogen-dependency of the bladder and urethral function and the coordinated activation of pelvic floor muscles (PFM) during micturition.Methods: We allocated age-matched female rabbits to control, 1-month ovariectomized (OVX), and OVX plus 2-week estradiol benzoate (EB) groups to record cystometry, urethral pressure, and electromyograms of bulbospongiosus (Bsm), and pubococcygeus muscles (Pcm) simultaneously. We also measured serum estradiol levels and myofiber cross-sectional area. We assessed urodynamic and urethral variables, categorized the Bsm-Pcm activation patterns at storage and voiding phases, and obtained the power spectrum density of muscle activation around the voiding phase. We investigated the influence of ovarian hormones, in general, and the contribution of estrogen, particularly on the functions of the bladder, urethra, and PFM. Statistical significance was set at P < 0.05.Results: Ovarian hormones influence the bladder, urethral, and PFM functions. The urodynamics analyses indicated estrogens contribute to voiding duration and, to a lesser extent, to the time between bladder contractions. Urethral pressure at closure (maximal pressure-to-maximal urethral pressure ratio) improved partially (8%, P < 0.05) in the OVX plus 2-week estradiol benzoate compared with OVX, but urethral resistance increased ($1.9-fold, P < 0.05) compared with control rabbits. Our findings support that Pcm activity at voiding is estrogensensitive, albeit EB administration reduced it at storage resume, which relates to high urethral resistance.Conclusions: Ovariectomy impairs bladder and urethral pressures and Bsm and Pcm activation at micturition in anesthetized rabbits. Estrogen administration partially reverts some of these effects and influences Pcm activation.

show abstract

Section: Discussionsupporting

confidence: 63%

“…Although, in rats, the Pcm myofiber CSA seems more responsive to estrogens that induce a CSA reduction. 27,28 Overall, we believe these findings shed light on the understanding of menopausal hormone therapy on PFM morphometry. 29 Reduced estradiol levels undermine bladder contractility in rabbits.…”

Section: Discussionmentioning

confidence: 66%

Estrogens influence differentially on the pelvic floor muscles activation at somatovisceral reflexes involved in micturition of rabbits

et al. 2021

View full text Add to dashboard Cite

show abstract

“…In rat, the organization of pelvic skeletal muscles, coccygeus, iliocaudalis, and pubocaudalis, are anatomically similar to human PFMs. 24,25 Furthermore, we recently reported that with respect to major architectural parameters, rat PFM design is similar to human. 26 Rat has also been shown to be a reliable model for the study of pregnancy-related changes in cervix, vagina, and vaginal supportive structures.…”

mentioning

confidence: 89%

Pregnancy-induced adaptations in the intrinsic structure of rat pelvic floor muscles

Alperin

Lawley

Esparza

et al. 2015

American Journal of Obstetrics and Gynecology

View full text Add to dashboard Cite

OBJECTIVE Maternal birth trauma to the pelvic floor muscles (PFMs) is a major risk factor for pelvic floor disorders. Modeling and imaging studies suggest that demands placed on PFMs during childbirth exceed their physiologic limits; however many parous women do not sustain PFM injury. Here we determine whether pregnancy induces adaptations in PFM architecture, the strongest predictor of muscle function, and/or intramuscular extracellular matrix (ECM), responsible for load bearing. To establish if parallel changes occur in muscles outside of the PFM, we also examined a hind limb muscle. STUDY DESIGN Coccygeus, iliocaudalis, pubocaudalis, and tibialis anterior of 3-month-old Sprague-Dawley virgin, mid-pregnant, and late-pregnant; 6-month-old virgin; and 4- and 12-week postpartum rats (N = 10/group) were fixed in situ and harvested. Major architectural parameters determining muscle’s excursion and force-generating capacity were quantified, namely, normalized fiber length (Lfn), physiologic cross-sectional area, and sarcomere length. Hydroxyproline content was used as a surrogate for intramuscular ECM quantity. Analyses were performed by 2-way analysis of variance with Tukey post hoc testing at a significance level of .05. RESULTS Pregnancy induced a significant increase in Lfn in all PFMs by the end of gestation relative to virgin controls. Fibers were elongated by 37% in coccygeus (P < .0001), and by 21% in iliocaudalis and pubocaudalis (P < .0001). Importantly, no Lfn change was observed in the tibialis anterior. Physiologic cross-sectional area and sarcomere length were not affected by pregnancy. By 12 weeks’ postpartum, Lfn of all PFMs returned to the prepregnancy values. Relative to virgin controls, ECM increased by 140% in coccygeus, 52% in iliocaudalis, and 75% in pubocaudalis in late-pregnant group, but remained unchanged across time in the tibialis anterior. Postpartum, ECM collagen content returned to prepregnancy levels in iliocaudalis and pubocaudalis, but continued to be significantly elevated in coccygeus (P < .0001). CONCLUSION This study demonstrates that pregnancy induces unique adaptations in the structure of the PFMs, which adjust their architectural design by adding sarcomeres in series to increase fiber length as well as mounting a substantial synthesis of collagen in intramuscular ECM.

show abstract

“…[4][5][6][7][8] Estrogen replacement therapy is commonly prescribed for the treatment of pelvic dysfunctions; however, its efficacy is controversial. 9 The effect of the estrogen administration on periurethral skeletal muscles has been previously approached, 6,8,10,11 although some issues regarding their estrogenic sensitivity remain to be addressed. Estrogens influence mass, contractile properties, damage/repair processes and the expression of ER in hindlimb skeletal muscles.…”

Section: Introductionmentioning

confidence: 99%

Aromatase expression is linked to estrogenic sensitivity of periurethral muscles in female rabbits

Carrasco-Ruiz

García-Villamar

López-García

et al. 2015

Cell Biochemistry & Function

Self Cite

View full text Add to dashboard Cite

Beyond its role in the conversion of androgens to estrogens, the expression of aromatase could influence on the estrogenic signalling in targeted tissues. Considering the well-defined biochemical and physiological differences between the pubococcygeus (Pcm) and bulbospongiosus (Bsm) muscles in female rabbits, it is presently hypothesized that the aromatase expression is differentially linked to the estrogen sensitivity of each muscle. To this end, serum estradiol levels and the aromatase expression, presence of ERα and ERβ and morphometry were evaluated in the Pcm and Bsm of female rabbits allocated in control, ovariectomized (OVX) and OVX treated with estradiol benzoate (OVX + EB) groups. Aromatase expression was high in the Pcm. Independently to serum estradiol, ovariectomy increased aromatase expression in the Pcm while decreased it in the Bsm. The EB treatment avoided the effect of ovariectomy only in the Pcm. The number of immunoreactive nuclei anti-ERα and anti-ERβ was high in the Pcm of OVX and OVX + EB rabbits, while those in the Bsm remained unchanged. The number of peripheral nuclei per fibre and the cross-sectional area-to-myonucleus ratio were modified only in the Pcm. Our findings support aromatase expression in the Pcm, and Bsm of rabbits is differentially linked to estrogenic sensitivity of each muscle.

show abstract

The Effects of Castration and Hormone Replacement on the Cross‐Sectional Area of Pubococcygeus Muscle Fibers in the Female Rat

Cited by 12 publications

References 51 publications

Estrogens influence differentially on the pelvic floor muscles activation at somatovisceral reflexes involved in micturition of rabbits

Estrogens influence differentially on the pelvic floor muscles activation at somatovisceral reflexes involved in micturition of rabbits

Pregnancy-induced adaptations in the intrinsic structure of rat pelvic floor muscles

Aromatase expression is linked to estrogenic sensitivity of periurethral muscles in female rabbits

Contact Info

Product

Resources

About