The striated urethral sphincter in female rats.
The aim of this study was to give a microscopic description of the organization, the innervation and the slow or fast type of the striated fibers of the external urethral sphincter in the female rat. Conventional methods for photonic microscopy and immunochemistry were applied to cross and longitudinal sections of snap-frozen urethra. With hematoxylin-eosin stained cross sections, striated fibers are of small diameter and attached directly to the surrounding connective tissue. They are innervated by cholinergic endplates as shown by acetylcholinesterase techniques and alpha-bungarotoxin binding. The histological aspects of the cross sections as well as the distribution of endplates along the length of the sphincter suggest an organization of the fibers in four bundles, possibly acting as a photographic diaphragm does. Like striated skeletal muscle fibers, the fibers bind monoclonal antibodies against dystrophin with subsarcolemmal distribution and against desmin which visualizes striations. All the fibers express fast myosin heavy chains and very few co-express slow myosin heavy chains as determined by immunocytochemistry. We are taking advantage of the diaphragmatic organization of the striated sphincter to develop a longitudinal section as a model of chronic incontinence to test the efficiency of grafted myoblasts provided by fast striated skeletal muscle.
Praud
Christophe
C
Atelier de régénération neuromusculaire, Faculté de Médecine St Antoine, 27 rue Chaligny, 75571 Paris Cedex 12, France. christophe.praud@chusa.jussieu.fr
Sebe
Philippe
P
Mondet
Fabrice
F
Sebille
Alain
A
D000110:Acetylcholinesterase / Q000032:analysis; D000818:Animals; D002038:Bungarotoxins / Q000032:analysis; D003893:Desmin / Q000032:analysis; D016189:Dystrophin / Q000032:analysis; D005260:Female; D018656:Muscle Fibers, Fast-Twitch / Q000737:chemistry / Q000166:cytology*; D018657:Muscle Fibers, Slow-Twitch / Q000737:chemistry / Q000166:cytology*; D018482:Muscle, Skeletal / Q000737:chemistry / Q000294:innervation*; D018995:Myosin Heavy Chains / Q000032:analysis; D009469:Neuromuscular Junction / Q000737:chemistry / Q000166:cytology; D051381:Rats; D017208:Rats, Wistar / Q000033:anatomy & histology* / Q000502:physiology; D014521:Urethra / Q000033:anatomy & histology*
D002038:Bungarotoxins; D003893:Desmin; D016189:Dystrophin; D000110:Acetylcholinesterase; D018995:Myosin Heavy Chains