title: The levator ani of the female rat: a suitable model for studying the effects of testosterone on the development of mammalian muscles.
abstract: The present results give evidence by using cytochemical markers of motor end-plates (ChE, AchR) and ultrastructural techniques that the Levator ani (LA) muscle is also present in adult females: it is composed of differentiated and innervated fibres. A significant difference, both on the number of fibres per muscle (n) and on their average cross-sectional area (acsa), was observed between sexes:-male: n = 5300 +/- 687, acsa: 522 +/- 68.6 microns 2;-female: n = 565 +/- 246.9, acsa: 68 +/- 8.6 microns 2. These results suggest that testosterone could control, at least partially, the number and the diameter of muscle fibres during development.
authors.affiliation: Université P. & M. Curie, Département de Cytologie, CNRS UA 1199; Paris.
authors.forename: C
authors.initials: C
authors.lastname: Tobin
authors.forename: Y
authors.initials: Y
authors.lastname: Joubert
mesh_terms: D000375:Aging; D000818:Animals; D002802:Cholinesterases / Q000378:metabolism*; D005260:Female; D006651:Histocytochemistry; D008854:Microscopy, Electron; D009045:Motor Endplate / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D024510:Muscle Development; D009132:Muscles / Q000378:metabolism / Q000648:ultrastructure; D009469:Neuromuscular Junction / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011950:Receptors, Cholinergic / Q000378:metabolism*; D012016:Reference Values; D013739:Testosterone / Q000494:pharmacology*
chemical_list: D011950:Receptors, Cholinergic; D013739:Testosterone; D002802:Cholinesterases