Influences of age, overload obtained through denervation of synergists, and training on the capillarisation of the m. plantaris were compared in 5-, 13- and 25-month-old rats in relation to different fibre types. Overload resulted in about 30% hypertrophy in each age group. Age effects were significant only in the deep (more oxidative) region of the muscle. From 5 to 13 months, the percentage of FOG fibres increased at the expense of FG fibres, while the fibre cross-sectional areas (FCSA) of each fibre type increased. From 13 to 25 months, the FCSA of FG fibres decreased, as did the local capillary-to-fibre ratio (LCFR) of each fibre type, indicating capillary loss and a declined capillary density for each fibre type (CFD). Overload effects were identical for both the superficial (more glycolytic) and the deep region for each age group. With overload, FCSA and LCFR of each fibre type increased, while CFD decreased, indicating that capillary proliferation occurred with overload, even at old age, although lagging behind increases in FCSAs. Training showed minor effects.

Download full-text PDF

Source
http://dx.doi.org/10.1016/0034-5687(93)90049-gDOI Listing

Publication Analysis

Top Keywords

fibre type
16
fibre types
8
age group
8
type increased
8
lcfr fibre
8
indicating capillary
8
fibre
6
age
5
overload
5
capillarisation fibre
4

Similar Publications

South Asia has high prevalence rates of type 2 diabetes (T2D). Until the 1990s, the prevalence of T2D within South Asia was low but much higher in the South Asian diaspora living abroad. Today, high prevalence rates of T2D are reported among those living in South Asia.

View Article and Find Full Text PDF

Insights into the role of phosphorylation on microtubule crosslinking by PRC1.

Mol Biol Cell

January 2025

Department of Biological Sciences, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.

The mitotic spindle is composed of distinct networks of microtubules, including interpolar bundles that can bridge sister kinetochore fibers and bundles that organize the spindle midzone in anaphase. The crosslinking protein PRC1 can mediate such bundling interactions between antiparallel microtubules. PRC1 is a substrate of mitotic kinases including CDK/cyclin-B, suggesting that it can be phosphorylated in metaphase and dephosphorylated in anaphase.

View Article and Find Full Text PDF

The Drosophila intrinsically disordered protein Ultrabithorax (Ubx) undergoes a series of phase transitions, beginning with noncovalent interactions between apparently randomly organized monomers, and evolving over time to form increasingly ordered coacervates. This assembly process ends when specific dityrosine covalent bonds lock the monomers in place, forming macroscale materials. Inspired by this hierarchical, multistep assembly process, we analyzed the impact of protein concentration, assembly time, and subphase composition on the early, noncovalent stages of Ubx assembly, which are extremely sensitive to their environment.

View Article and Find Full Text PDF

Gut Microbiota Metabolites Sensed by Host GPR41/43 Protect Against Hypertension.

Circ Res

January 2025

Hypertension Research Laboratory, School of Biological Sciences (R.R.M., T.Z., E.D., L.X., A.B.-W., H.A.J., M.N., M.P., K.C.L., W.Q., J.A.O.D., F.Z.M.).

Background: Fermentation of dietary fiber by the gut microbiota leads to the production of metabolites called short-chain fatty acids, which lower blood pressure and exert cardioprotective effects. Short-chain fatty acids activate host signaling responses via the functionally redundant receptors GPR41 and GPR43, which are highly expressed by immune cells. Whether and how these receptors protect against hypertension or mediate the cardioprotective effects of dietary fiber remains unknown.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!