Colocalization of ANG II and mRNA for the Renin-Angiotensin System Components in Cultured Rat Glomerular Epithelial and Mesangial Cells / 대한해부학회지

ABSTRACT

Mesangial cells are found to have renin and angiotensin II-AT1 receptors, but the presence of other components of the renin-angiotensin system and production of angiotensin II within the cell have not been demonstrated. The presence of the renin-angiotensin system components in the glomerular epithelial cell has not been previously reported. We studied expression of each component of the renin-angiotensin system in primary cultured rat glomerular epithelial cells and mesangial cells. We assessed mRNA expression by RT-PCR and the presence of angiotensin II by immunocytochemistry. Both cultured glomerular epithelial cells and mesangian cells expressed mRNA for components of the renin-angiotensin system such as renin, angiotensinogen and angiotensin II type 1A and 1B receptor subtypes. Immunocytochemical studies with specific antibody for angiotensin II demonstrated significant immunoreactivity in both glomerular epithelial cells and mesangian cells. These results, for the first time, provide direct evidence that both the glomerular epithelial cells and mesangian cells contain a complete renin-angiotensin system and generate angiotensin II with intracellular mechanisms. Further studies are required to define the subcellular localization of angiotensin II with electron microscopy and to elucidate the physiological importance of the intracellular reninangiotensin system.