Summary
Light and electron microscopic techniques have been used to determine the distribution, morphology and innervation of subepithelial striated muscle cells in the wall of the proximal urethra of the male guinea-pig. These cells form a continuous layer, immediately beneath the urethral epithelium extending from the bladder neck to the termination of the ejaculatory ducts into the proximal urethra. They differ from “typical” striated muscle fibres (as seen in the external urethral sphincter) by their small size, rich acetylcholinesterase content and the irregular arrangement of intracellular myofilaments and sarcoplasmic reticulum. In addition, motor end plate regions have not been observed on these striated cells when examined using a light microscopic histochemical technique. The cells are related to acetylcholinesterase positive nerves which run between them in a manner compatible with the occurrence of “en passant” synaptic interactions. Using electron microscopy, axonal varicosities containing small (50 nm diameter) agranular vesicles are encountered 50 nm from the striated cells; membrane specialisations characteristic of motor end plates have not been observed on the cells. The findings are discussed, particularly in relation to the distribution, unusual morphology and innervation of these subepithelial muscle cells.
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Bors, E., Comarr, A.E., Reingold, I.M.: Striated muscle fibres of the vesical neck. J. Urol. (Baltimore) 72, 191–196 (1954)
Gabella, G.: Striated muscle cells in the guinea-pig iris. Cell Tiss. Res. 154, 181–188 (1974)
Gomori, G.: Microscopic histochemistry. Principles and practice. Chicago: University of Chicago Press 1952
Gosling, J.A., Dixon, J.S.: The structure and innervation of smooth muscle in the wall of the bladder neck and proximal urethra. Brit. J. Urol. 47, 549–558 (1975)
Hay, E.D.: The fine structure of differentiating muscle in salamander tail. Z. Zellforsch. 59, 6–43 (1963)
Manley, C.B.: The striated muscle of the prostate. J. Urol. (Baltimore) 95, 234–240 (1966)
Masson, P.: Some histological methods: trichrome stainings and their preliminary technique. J. Tech. Meths. 12, 75–90 (1929)
Reynolds, E.S.: The use of lead citrate at high pH as an electron-opaque stain in electron microscopy. J. Cell Biol. 17, 208–212 (1963)
Sabatini, D.C., Bensch, K., Barrnett, R.J.: Cytochemistry and electron microscopy. The preservation of cellular ultrastructure and enzymatic activity by aldehyde fixation. J. Cell Biol. 17, 19–58 (1963)
Watson, M.: Staining of tissue sections for electron microscopy with heavy metals. J. biophys. biochem. Cytol. 4, 475–478 (1958)
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Dixon, J.S., Gosling, J.A. The morphology and innervation of subepithelial “striated” muscle cells in the male guinea-pig urethra. Cell Tissue Res. 174, 281–288 (1976). https://doi.org/10.1007/BF00222165
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DOI: https://doi.org/10.1007/BF00222165