Platinum open access journal
pISSN 2466-0493 eISSN 2466-054X
Indexed in MEDLINE, SCIE, Scopus, DOAJ and more
    Korean J Urol. 2007 Oct;48(10):1050-1057. Korean.
    Published online Oct 31, 2007.
    https://doi.org/10.4111/kju.2007.48.10.1050
    Copyright © 2007 The Korean Urological Association
    Original Article

    The Significance of Periurethral Fibrosis and the Change of Nitric Oxide Synthase Containing Nerves in the Urethra of Diabetic Rats

    Yeun Goo Chung, Hyung Sang Yoo,1 Yong-Hyun Kwon,2 Chang Shin Park,2 Woo Sung Lim, Ji Kan Ryu, Tack Lee and Sang Min Yoon
      • Department of Urology, Inha University College of Medicine, Incheon, Korea.
      • 1Yoo Urology Clinic, Suwon, Korea.
      • 2Department of Pharmacology, Inha University College of Medicine, Incheon, Korea.
    • Corresponding author (Email: uroyoon@inha.ac.kr )
    Received June 05, 2007; Accepted August 28, 2007.

    Abstract

    Purpose

    We have previously demonstrated that increased urethral resistance was more prominent in diabetic rats than in controls. This may result from a compressive obstruction such as damage of the urethral nerve containing nitric oxide. Another possible cause for urethral obstruction could be a constrictive obstruction such as a periurethral fibrosis. In the present study, we investigated the changes in the expression of nitric oxide synthase (NOS) isoforms (compressive obstruction) and collagen subtypes (constrictive obstruction) in the urethral tissues of non-insulin dependent diabetic rats.

    Materials and Methods

    Thirty-six male Sprague-Dawley rats (18 diabetic rats and 18 control rats), bred from birth, were included in this study. Diabetes mellitus was induced by intraperitoneal administration of streptozotocin (90mg/kg) on the second day after birth. Urethral tissues were harvested at 12, 24 and 36 weeks after induction of diabetes and were stained for neuronal NOS (nNOS) and Masson trichrome. We also performed reverse transcriptase-polymerase chain reaction or Western blot analysis to evaluate mRNA or protein expression of NOS isoforms and collagen subtypes in the urethral tissues.

    Results

    Immunohistochemical staining and Western blot analysis of nNOS revealed that the immunoreactivity and nNOS expression in the urethra was lower in the diabetic rats than in the controls. The Masson trichrome staining showed that there was urethral fibrosis in the diabetic rats. The mRNA or protein expression of collagen subtypes, especially type I collagen, were higher in the diabetic rat urethra than in the controls.

    Conclusions

    These data suggest that the increased urethral resistance in diabetic rats may be attributable to a decrease in the urethral nNOS expression and an increase in collagen content. Urethral dysfunction as well as a cystopathy may play an important role in the pathogenesis of diabetes-induced voiding dysfunction.

    Keywords
    Diabetic cystopathy; Urethra; Nitric oxide; Collagen

    Figures

    Fig. 1
    Immunohistochemical staining for the nNOS in the urethra of control (A series) and diabetic (B series) rats at 24 weeks of age. The nNOS immunoreactivities in each area were lower in the diabetic rats than the activities in the controls. Arrows denote nNOS-positive nerve fibers. Left figures, lamina propria (×200); Middle figures, smooth muscle layer (×400); Right figures, adventitia (×400). NOS: nitric oxide synthase.

    Fig. 2
    Western blot for nNOS and eNOS. (A) Representative gel pictures showing the protein expression of nNOS and eNOS in rat urethral tissues. (B) The nNOS protein expression was lower in the diabetic rats than in the controls at 24 and 36 weeks of age. (C) The eNOS protein expression was lower in diabetic rats than in the controls at 24 weeks of age. β-actin was used as a loading control. CON: control group, STZ: streptozotocin-induced diabetic group, NOS: nitric oxide synthase.

    Fig. 3
    Masson trichrome staining in 12-week-old control rats (A), 12-week-old diabetic rats (B), 24-week-old control rats (C), 24-week-old diabetic rats (D), 36-week-old control rats (E), and 36-week-old diabetic rats (F). Urethral fibrosis as evidenced by increase of collagen content compared to control rats was noted in diabetic rats.

    Fig. 4
    RT-PCR for type I and type III collagen subtypes. (A) Representative gel pictures showing the gene expression of type I and type III collagen in rat urethral tissues. (B) The gene expression of type I collagen was higher in the diabetic rats than in the controls at 12 and 24 weeks of age. (C) No significant difference was found in the gene expression of type III collagen between the groups. GAPDH was used as an internal control for the RT-PCR. CON: control group, STZ: streptozotocin-induced diabetic group, GAPDH: glyceraldehyde-3-phosphate dehydrogenase, RT-PCR: reverse transcript-polymerase chain reaction.

    Fig. 5
    Western blot analysis for type I collagen. (A) Representative gel pictures showing the protein expression of type I collagen in rat urethral tissues. (B) The expression of type I collagen was higher in the diabetic rats than in controls at 12 and 24 weeks of age. β-actin was used as a loading control. CON: control group, STZ: streptozotocin-induced diabetic group.

    Tables

    Table 1
    Primer sequences

    Table 2
    Nitric oxide synthase immunoreactivity in urethral nerves

    References

      1. Kim SA, Park WS, Ohrr HC, Kang HY, Lee DH, Yi SW, et al. Prevalence and management status of diabetes mellitus in Korea. Korean J Med 2005;68:10–17.
      1. Bryfogle JW, Bradley RF. The vascular complications of diabetes mellitus: a clinical study. Diabetes 1957;6:159–167.
      1. Vinik AI, Holland MT, Le Bear JM, Liuzze FJ, Stansberry KB, Colen LB. Diabetic neuropathies. Diabetes Care 1992;15:1926–1975.
      1. Frimodt-Moller C. Diabetic cystopathy: epidemiology and related disorders. Ann Intern Med 1980;92:318–321.
      1. Motzkin D. The significance of deficient bladder sensation. J Urol 1968;100:445–450.
      1. Ellenberg M. Development of urinary bladder dysfunction in diabetes mellitus. Ann Intern Med 1980;92:321–323.
      1. Mumtaz FH, Sullivan ME, Thompson CS, Dashwood MR, Naseem KM, Bruckdorfer KR, et al. Alterations in the nitric oxide synthase binding sites and non-adrenergic, non-cholinergic mediated smooth muscle relaxation in the diabetic rabbit bladder outlet: possible relevance to the pathogenesis of diabetic cystopathy. J Urol 1999;162:558–566.
      1. Derek JG. Pressure-flow studies of micturiation. Urol Clin North Am 1996;23:279–297.
      1. Schafer W. The contribution of the bladder outlet to the relation between pressure and flow rate during micturition. In: Hinman F Jr, editor. Benign prostatic hypertrophy. New York: Springer-Verlag; 1983. pp. 470.
      1. Eika B, Levin RM, Longhurst PA. Collagen and bladder function in streptozotocin-diabetic rats: effects of insulin and aminoguanidine. J Urol 1992;148:167–172.
      1. Koo HP, Santarosa RP, Buttyan R, Shabsigh R, Olsson CA, Kaplan SA. Early molecular changes associated with streptozotocin-induced diabetic bladder hypertrophy in the rat. Urol Res 1993;21:375–381.
      1. Hellweg R, Hartung HD. Endogenous levels of nerve growth factor (NGF) are altered in experimental diabetes mellitus: a possible role for NGF in the pathogenesis of diabetic neuropathy. J Neurosci Res 1990;26:258–267.
      1. Kim JC, Seo SL, Park YH, Hwang TK. Changes of detrusor contractility and growth factors in streptozotocin-induced NIDDM rat. Korean J Urol 2000;41:615–621.
      1. Chung JS, Yoo HS, Lee T. Urethral dysfunction in a non-insulin dependent diabetes mellitus rat model. Korean J Urol 2006;47:1007–1012.
      1. Weir GC, Clore ET, Zmachinski CJ, Bonner-Weir S. Islet secretion in a new experimental model for non-insulin-dependent diabetes. Diabetes 1981;30:590–595.
      1. Sasaki K, Chancellor MB, Phelan MW, Yokoyama T, Fraser MO, Seki S, et al. Diabetic cystopathy correlates with a long-term decrease in nerve growth factor levels in the bladder and lumbosacral dorsal root Ganglia. J Urol 2002;168:1259–1264.
      1. Low PA, Tuck RR, Dyck PJ, Schmelzer JD, Yao JK. Prevention of some electrophysiologic and biochemical abnormalities with oxygen supplementation in experimental diabetic neuropathy. Proc Natl Acad Sci USA 1984;81:6894–6898.
      1. Thrainsdottir S, Malik RA, Dahlin LB, Wiksell P, Eriksson KF, Rosen I, et al. Endoneurial capillary abnormalities presage deterioration of glucose tolerance and accompany peripheral neuropathy in man. Diabetes 2003;52:2615–2622.
      1. Buck AC, Reed PI, Siddiq YK, Chisholm GD, Fraser TR. Bladder dysfunction and neuropathy in diabetes. Diabetologia 1976;12:251–258.
      1. Sima AA, Nathaniel V, Bril V, McEwen TA, Greene DA. Histopathological heterogeneity of neuropathy in insulin-dependent and non-insulin-dependent diabetes, and demonstration of axo-glial dysjunction in human diabetic neuropathy. J Clin Invest 1988;81:349–364.
    Cited by
    Crossref 1
    Google Scholar 
    Scopus 1
    MeSH Terms
    Animals
    Blotting, Western
    Collagen
    Collagen Type I
    Diabetes Mellitus
    Fibrosis*
    Humans
    Male
    Neurons
    Nitric Oxide Synthase*
    Nitric Oxide*
    Parturition
    Protein Isoforms
    RNA, Messenger
    Rats*
    Rats, Sprague-Dawley
    Urethra*
    Urethral Obstruction
    Metrics
    Share
    Figures
    slide
    slide
    slide
    slide
    slide

    1 / 5

    Tables
    slide
    slide

    1 / 2

    PERMALINK