Evidence of apoptosis in the castration-induced atrophy of the rat levator ani muscle.
Apoptosis or programmed cell death has been previously reported in androgen-responsive tissue such as the prostate. We tested the hypothesis that apoptosis may also represent a component of the castration-induced atrophy of the sexually dimorphic levator ani (LA) muscle of the male rat. Gonadectomy (GDX) induced a severe decrease in the LA muscle wet weight accompanied by important modifications in cytoarchitecture including an increase in myofibrillar interspace and condensed mitochondria. These alterations were almost completely reversed after 7 days of testosterone propionate replacement therapy (GDX + TP). In GDX rats, internucleosomal DNA fragmentation was confirmed by both agarose gel electrophoresis and electron microscopy. DNA fragmentation was no longer detected in GDX + TP rats. In GDX rats, overexpression of the trpm-2/clusterin gene, used as an early marker of apoptosis, further confirmed that an apoptotic response, typical of androgen-responsive tissues, is taking place following androgen withdrawal.
Boissonneault
G
G
Département de Biochimie, Université de Sherbrooke, Québec, Canada. gboisson@courrier.usherb.ca
D000818:Animals; D017209:Apoptosis; D002843:Chromatin / Q000648:ultrastructure; D051152:Clusterin; D053938:DNA Fragmentation; D015870:Gene Expression; D006023:Glycoproteins / Q000235:genetics; D008297:Male; D008854:Microscopy, Electron; D008931:Mitochondria, Muscle / Q000648:ultrastructure; D018832:Molecular Chaperones / Q000235:genetics; D018485:Muscle Fibers, Skeletal / Q000473:pathology; D018482:Muscle, Skeletal / Q000473:pathology*; D009133:Muscular Atrophy / Q000209:etiology*; D009210:Myofibrils / Q000648:ultrastructure; D009919:Orchiectomy / Q000009:adverse effects*; D009929:Organ Size; D010388:Pelvis; D051381:Rats; D017207:Rats, Sprague-Dawley; D013739:Testosterone / Q000008:administration & dosage
D002843:Chromatin; D051152:Clusterin; D006023:Glycoproteins; D018832:Molecular Chaperones; D013739:Testosterone