Gray MA, Wang CC, Sacks MS, Yoshimura N, Chancellor MB, Nagatomi J. Time-dependent alterations of select genes in streptozotocin-induced diabetic rat bladder.
Urology 2008;
71:1214-9. [PMID:
18279932 DOI:
10.1016/j.urology.2007.11.054]
[Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2007] [Revised: 10/23/2007] [Accepted: 11/12/2007] [Indexed: 10/22/2022]
Abstract
OBJECTIVES
To investigate time-course changes in the expression of select genes and extracellular matrix proteins in the bladder of rats with streptozotocin-induced diabetes, so as to examine the mechanisms underlying changes in mechanical properties of the bladder due to diabetic cystopathy.
METHODS
Female Sprague-Dawley rats were injected with streptozotocin (65 mg/kg). Rats that were fed with 5% sucrose in drinking water served as diuretic controls, in addition to normal control rats. At the end of 2, 4, and 8 weeks, total ribonucleic acid (RNA) isolated from the detrusor layer of the bladders was reverse transcribed, and then complementary deoxyribonucleic acid was amplified with polymerase chain reaction primer sets for type I collagen, type III collagen, tropoelastin, and transforming growth factor beta 1 (TGF-beta-1). Collagen and elastin contents of the bladders were quantified with commercially available assays.
RESULTS
Both diabetic and diuretic rat bladders exhibited significantly (P <0.05) lower expression of type I collagen and TGF-beta-1 messenger RNA (mRNA) compared with normal controls at all time points tested. In contrast, downregulation of type III collagen mRNA expression in both diabetic and diuretic groups was seen at 4 and 8 weeks. Furthermore, tropoelastin mRNA expression in the diabetic rat bladders was, compared with normal and diuretic rats, significantly (P <0.05) greater at 2 weeks. Both diabetic and diuretic rat bladders exhibited significantly (P <0.05) decreased collagen and increased elastin protein content at 2 and 8 weeks.
CONCLUSIONS
The results of the present study suggest that increases in compliance of the bladders in diabetic cystopathy result not only from diuresis-driven reduction of collagen synthesis but also from increased elastin synthesis.
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