HISTOLOGICAL AND IMMUNOHISTOCHEMICAL STUDY TO DETECT SMOOTH MUSCLES IN THE MUCOSA OF HUMAN MALE URINARY BLADDER
Dalia M. Elmarakby
Department of Histology, Faculty of Medicine, Cairo University
Although few studies were carried out to detect smooth muscles in mucosa of the human urinary bladder but the presence of such muscles was proved by many authors. Thus the present study aimed to detect smooth muscles and their possible pattern of distribution in the lamina propria of mucosa of the human urinary bladder. Forty two human males urinary bladder specimens were taken from the safety margin after cystectomies with their age ranged from 22-69 years. Smooth muscles estimated by histological examination of H&E and Masson trichrome stained sections and by immunohistochemical staining of alpha smooth muscle actin (α-SMA). Histological examination revealed that Masson trichrome detected smooth muscles in lamina propria of all examined cases while H&E revealed smooth muscles in 37 cases. Distribution of muscles was mostly in the form of scattered small bundles or fibres (64% of examined cases). Interrupted bundles were detected in 24% & 36% of cases in H&E and Masson trichrome respectively. The present study showed that in H&E and Masson trichrome stained sections the smooth muscles were mostly found in the superficial part of lamina propria (61% & 64% respectively )and less commonly in the middle (19% & 26%) or widely distributed in the lamina propria (7% & 10%) respectively. Regarding the immunohistochemical results of the present study, there was no difference in the prevalence, pattern as well as locations of smooth muscles that were detected by α-SMA staining and those were detected by Masson trichrome. However, α-SMA was more accurate in detecting very fine muscle fibres in certain areas that could not be accurately detected by Masson trichrome. In conclusion smooth muscles were detected in the lamina propria of mucosa of adult human male urinary bladder sections but further wide scaled studies are needed to know if these muscles represent a proper muscularis mucosa or not and its suggested function. More studies should be carried out on foetal and infantile urinary bladders to know if such smooth muscles exist in their urinary bladder mucosa or it is reactionally present with progression of age.