- Lid geworden
- 8 okt 2010
- Berichten
- 33.541
- Waardering
- 22.297
- Lengte
- 1m96
- Massa
- 102kg
- Vetpercentage
- 11%
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2825614/
Samengevat werd er DHT gebruikt om te kijken naar de niet-genomische effecten (d.w.z. SNELLE effecten die dus niet via gen expressie verlopen) die androgenen teweeg brengen in spierweefsel (van muizen). Maximale isometrische kracht werd gemeten en DHT verhoogde dit; ogenschijnlijk via een membraan receptor waarna een signaleringscascade ontstaat die uiteindelijk zorgt voor fosforylatie van de regulatory myosine light chains.
Kende zelf deze specifieke studie nog niet.
J Physiol. 2010 Feb 1;588(Pt 3):511-25. doi: 10.1113/jphysiol.2009.182162. Epub 2009 Dec 14.
Dihydrotestosterone activates the MAPK pathway and modulates maximum isometric force through the EGF receptor in isolated intact mouse skeletal muscle fibres.
Hamdi MM, Mutungi G.
Author information
Abstract
It is generally believed that steroid hormones have both genomic and non-genomic (rapid) actions. Although the latter form an important component of the physiological response of these hormones, little is known about the cellular signalling pathway(s) mediating these effects and their physiological functions in adult mammalian skeletal muscle fibres. Therefore, the primary aim of this study was to investigate the non-genomic actions of dihydrotestosterone (DHT) and their physiological role in isolated intact mammalian skeletal muscle fibre bundles. Our results show that treating the fibre bundles with physiological concentrations of DHT increases both twitch and tetanic contractions in fast twitch fibres. However, it decreases them in slow twitch fibres. These changes in force are accompanied by an increase in the phosphorylation of MAPK/ERK1/2 in both fibre types and that of regulatory myosin light chains in fast twitch fibres. Both effects were insensitive to inhibitors of Src kinase, androgen receptor, insulin-like growth factor 1 receptor and platelet-derived growth factor receptor. However, they were abolished by the MAPK/ERK1/2 kinase inhibitor PD98059 and the epidermal growth factor (EGF) receptor inhibitor tyrphostin AG 1478. In contrast, testosterone had no effect on force and increased the phosphorylation of ERK1/2 in slow twitch fibres only. From these results we conclude that coïtus steroids have non-genomic actions in isolated intact mammalian skeletal muscle fibres. These are mediated through the EGF receptor and one of their main physiological functions is the enhancement of force production in fast twitch skeletal muscle fibres.
Samengevat werd er DHT gebruikt om te kijken naar de niet-genomische effecten (d.w.z. SNELLE effecten die dus niet via gen expressie verlopen) die androgenen teweeg brengen in spierweefsel (van muizen). Maximale isometrische kracht werd gemeten en DHT verhoogde dit; ogenschijnlijk via een membraan receptor waarna een signaleringscascade ontstaat die uiteindelijk zorgt voor fosforylatie van de regulatory myosine light chains.
Kende zelf deze specifieke studie nog niet.
Laatst bewerkt: