Removal of ovarian hormones from mature mice detrimentally affects muscle contractile function and myosin structural distribution.

Estradiol replacement reverses ovariectomy-induced muscle contractile and myosin dysfunction in mature female mice.

Skeletal muscle contractility and myosin function decline following ovariectomy in mature female mice. In the present study we tested the hypothesis that estradiol replacement can reverse those declines. Four-month-old female C57BL/6 mice (n = 69) were ovariectomized (OVX) or sham operated. Some mice were treated immediately with placebo or 17beta-estradiol (OVX + E(2)) while other mice were tr...

Molecular and cellular contractile dysfunction of dystrophic muscle from young mice.

The purpose of this study was to determine whether contractile protein alterations are responsible for force deficits in young dystrophic muscle. Contractility of intact extensor digitorum longus muscles and permeabilized fibers from wild-type (wt), dystrophin-deficient (mdx), and dystrophin/utrophin-deficient (mdx:utrn-/-) mice aged 21 and 35 days was determined. Myosin structural dynamics wer...

Age-related decline in actomyosin structure and function.

This review focuses on the role of changes in the contractile proteins actin and myosin in age-related deterioration of skeletal muscle function. Functional and structural changes in contractile proteins have been determined indirectly from specific force and unloaded shortening velocity of permeabilized muscle fibers, and were detected directly from site-directed spectroscopy in muscle fibers ...

Sulpiride-Induced Hyperprolactinemia in Mature Female Rats: Evidence for Alterations in The Reproductive System, Pituitary and Ovarian Hormones

Assembly of ring canals in the male germ line from structural components of the contractile ring.

Stable intercellular bridges called ring canals form following incomplete cytokinesis, and interconnect mitotically or meiotically related germ cells. We show that ring canals in Drosophila melanogaster males are surprisingly different from those previously described in females. Mature ring canal walls in males lack actin and appear to derive directly from structural proteins associated with th...