| 1 | Effect of lipopolysaccharide on expression andcharacterization of cholecystokinin receptorsin rat pulmonary interstitial macrophages显示文摘AIM: To investigate the effect of lipopolysaccharide (LPS) on the expression and the binding characteristics of cholecystokinin receptors (CCK-R) in rat pulmonary interstitial macrophages (PIMs). METHODS: The PIMs isolated from rat lung tissues were purified by the collagenase digestion method combined with alveolar lavage and pulmonary vessel perfusion. The expression of CCK-R mRNA was detected by RT-PCR and Southern blot analysis and the binding experiments were performed by radioligand binding assay (RBA). RESULTS: CCK-A receptor (CCK-AR) and CCK-B receptor (CCK-BR) mRNA were detected in rat PIMs and their RT-PCR amplified products had a size of approximately 1.37 kb and 480 bp, respectively. The relative expression of CCK-BR mRNA was higher than that of CCK-AR mRNA after incubation with LPS for 0.5, 2, and 6 h. The expression of CCK-R mRNA could be upregulated obviously by LPS. Southern blot analysis of RT-PCR amplified CCK-AR and CCK-BR mRNA products using [γ-^32p]ATP 5'-end-labelled probe showed specific hybridization bands. The specific binding of [^3H] CCK-8S to rat PIM membranes was detected in the rats administered with LPS for 48 h, but not in normal rats. Scatchard analysis of the saturation curves suggested the presence of CCK-R with a high affinity (Kd=0.68±0.28 nmol/L) and a low binding capacity (Bmax=32.5±2.7 fmol·mg^-1 protein) in rat PIMs. The specific binding of [^3H] CCK-8S to rat PIM membranes was inhibited by unlabelled CCK-8S (IC50=2.3±0.8 nmol/L), CCK-AR specific antagonist CR1409 (IC50=0.19±0.06 μmol/L) and CCK-BR specific antagonist CR2945 (IC50=3.2±1.1 nmol/L). CONCLUSION: Two types of functional CCK-AR and CCK-BR existed in rat PIMs and their expression could be upregulated by LPS. | Shun-jiangXU Wei-juanGAO BinCONG Yu-xiaYAO Zhen-yongGU | 2004 | Acta Pharmacologica Sinica2004，25，10： | 9 |
| 2 | Expression and cell-specific localization of cholecystokinin receptors in rat lung显示文摘AIM: To eluddate whether CCK receptors exist in lung tissues and their precise cellular localization in the lung.METHODS: CCK-AR and CCK-BR mRNA expression and cellular distribution in the rat lung were detected by highly sensitive method of/n $I^J reverse transcription-polymerase chain reaction (RT-PCR) and conventional in situ hybridization.RESULTS: CCK-AR and CCK-BR gene positive signals were observed in bronchial epithelial cells, alveolar epithelial cells,pulmonary macrophages and vascular endothelial cells of the rats' lung by in sitv RT-PCR. The hybridization signals of CCK-AR were relatively faint. By in sitv hybridization,however, only the signals of CCK-BR but not CCK-AR were detected in the lung, and the positive staining was only found in vascular endothelial cells and macrophages.CONCLUSION: CCK-AR and CCK-BR gene were present in pulmonary vascular endothelial cells, macrophages, bronchial epithelial cells and alveolar epithelial cells, which play an important role in mediating the regulatory actions of CCK-8 on these cells. | Shu-JinLi Yi-LingLing Yu-XiaYao Zhen-YongGu Jun-XiaWang Hong-YuYou BinCong | 2003 | World Journal of Gastroenterology2003，9，6： | 6 |
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