Published online Jun 15, 2003. doi: 10.3748/wjg.v9.i6.1273
Revised: February 4, 2003
Accepted: February 11, 2003
Published online: June 15, 2003
AIM: To elucidate 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 in situ 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 situ RT-PCR. The hybridization signals of CCK-AR were relatively faint. By in situ 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.