Chen Y, Gustafsson B, Arnqvist H J
Department of Cellbiology, Faculty of Health Sciences, University of Linköping and University Hospital, Sweden.
Am J Physiol. 1997 Feb;272(2 Pt 1):E297-303. doi: 10.1152/ajpendo.1997.272.2.E297.
Because the locally produced insulin-like growth factor-binding proteins (IGFBP) may influence bladder hypertrophy, either directly or by their interaction with insulin-like growth factor I (IGF-I), we studied the IGF system during the development of urinary bladder hypertrophy in rats with streptozotocin-induced diabetes. Messenger RNA for IGF-I, IGFBP-2, and IGFBP-4 was determined by solution hybridization. The bladder wet weight was elevated after 7 days. DNA synthesis was increased and peaked at 2 days, whereas DNA content per bladder wet weight was decreased by 7 days. The IGF-I mRNA did not change during the first 7 days and then decreased, and IGFBP-4 mRNA was increased transiently on day 7. On the other hand, IGFBP-2 mRNA was significantly increased after 1 day (2-fold), peaked by 7 days (6.4-fold), and then declined to approximately 50% above control at the end of experiment. This was associated with an increased IGFBP-2 protein content. Our results suggest that both stretching of the bladder due to diuresis and the diabetic state contribute to changes of the IGF system in the hypertrophying bladder.
由于局部产生的胰岛素样生长因子结合蛋白（IGFBP）可能直接或通过与胰岛素样生长因子I（IGF-I）相互作用影响膀胱肥大，我们研究了链脲佐菌素诱导的糖尿病大鼠膀胱肥大发展过程中的IGF系统。通过溶液杂交测定IGF-I、IGFBP-2和IGFBP-4的信使RNA。7天后膀胱湿重升高。DNA合成增加并在第2天达到峰值，而每膀胱湿重的DNA含量在7天时下降。IGF-I mRNA在前7天没有变化，然后下降，IGFBP-4 mRNA在第7天短暂增加。另一方面，IGFBP-2 mRNA在1天后显著增加（2倍），在7天时达到峰值（6.4倍），然后在实验结束时降至比对照高约50%。这与IGFBP-2蛋白含量增加有关。我们的结果表明，利尿引起的膀胱扩张和糖尿病状态都有助于肥大膀胱中IGF系统的变化。
