title: Testosterone control of endplate and non-endplate acetylcholinesterase in the rat levator ani muscle.
abstract: The time course of effects of castration (5-60 days) and testosterone treatment (15-60 days) of adult male rats were examined on the endplate (+EP) and non-endplate (-EP) acetylcholinesterase (AChE) of the androgen-dependent levator ani (LA) muscle. The thiocholine method was used to determine the enzyme activity. Castration caused LA muscle atrophy within 5 days but reduced the -EP and +EP AChE after 10 and 20 days, respectively. Following 30 days castration -EP and +EP AChE reached respectively 41% and 35% of control activity. Testosterone retrieval restored the control values of both muscle weight and total AChE after 15 and 60 days, respectively. Recovery of the +EP AChE preceded that of -EP AChE by 30 days. The results showed that in the rat LA muscle, +EP and -EP AChE depend on a continuous testosterone regulation that predominates at +EP region spreading thereafter to -EP region. Those data suggest a hormone regulation of AChE exerted indirectly through the synthesis and release of neurotrophic substances.
authors.affiliation: Department of Pharmacology, Escola Paulista de Medicina, São Paulo, Brazil.
authors.forename: R O
authors.initials: RO
authors.lastname: Godinho
authors.forename: C
authors.initials: C
authors.lastname: Souccar
authors.forename: A J
authors.initials: AJ
authors.lastname: Lapa
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism*; D000375:Aging / Q000378:metabolism*; D000818:Animals; D003692:Delayed-Action Preparations; D008297:Male; D009045:Motor Endplate / Q000187:drug effects / Q000201:enzymology*; D024510:Muscle Development; D009132:Muscles / Q000187:drug effects / Q000201:enzymology*; D009919:Orchiectomy; D051381:Rats; D017208:Rats, Wistar; D012016:Reference Values; D013739:Testosterone / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D003692:Delayed-Action Preparations; D013739:Testosterone; D000110:Acetylcholinesterase