The Regulation of Inducible Nitric Oxide Synthase in Pregnant Rat Uteri

• Main Authors: Wen-Lung Ma, 馬文隆
• Other Authors: Mei-Ling Tsai
• Format: Others
• Language: en_US
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/28409007860742272743

碩士 === 國立成功大學 === 生理學研究所 === 87 === ABSTRACT Introduction: Inducible form of nitric oxide synthase (iNOS) can convert L-arginine to L-citrulline and then generate a free radical, nitric oxide (NO). Both mRNA and protein of iNOS gene are detected in pregnant rat uteri. The regulation of iNOS in macrophages and smooth muscle cell can be modulated by inflammatory cytokines, such as interleukine-1b (IL-1b), and suppressed by TGFb1 (Transforming Growth Factor 1). However, the regulation of iNOS in pregnant uterus is still not well characterized. Several cytokines are detected in decidual tissues or amniotic fluid of pregnant mouse. Therefore, the purpose of this study was to examine which one of them is a possible regulator on the expression of uterine iNOS in the pregnant rats. Objectives: For working model, uteri from pregnant Wistar rats were used. Three specific aims of this study were to characterize 1) the expression pattern of iNOS protein throughout gestation period, 2) the effect of IL-1b on the expression of iNOS, and 3) the effect of TGFb2 on the expression of iNOS. Methods: The protein abundance of iNOS was measured by immunoblotting, and the amount of IL-1b mRNA level was measured by RT-PCR. Results: 1) Two peaks in the iNOS profile during pregnancy were observed: one on G10 when decidualization was at the maximal level, the other on G18 when uterine was quiescent. 2) The maximal expression of IL-1b mRNA were detected in late gestation uteri. 3) IL-1b, known as pro-inflammatory cytokine , suppressed the iNOS expression. 4) TGFb2, known as an immunosuppressor, enhanced the iNOS expression. Conclusion: Both IL-1b and TGFb2 might modulate the iNOS expression in uteri of pregnant rat. The regulation of iNOS by IL-1b and TGFb2 in uterus of pregnant rat was opposite to that in macrophage. Significance: The expression profile of iNOS in uterus during pregnancy uterus may play a role in decidual formation.