A COMPETITIVE DELETION MUTANT QUANTITATIVE PCR ASSAY FOR ANGIOTENSIN-CONVERTING ENZYME MESSENGER-RNA IN SMOOTH-MUSCLE CELLS

To quantify angiotensin-converting enzyme (ACE) mRNA, we have develope d a reverse transcription (RT)-coupled competitive PCR (RT-PCR) assay with a deletion mutant internal standard. The RT-PCR detects ACE mRNA from both human and bovine sources. ACE mRNA was detected in total RNA from cultured human saphenous vein smooth muscle cells (HuSV-SMCs) an d from bovine pulmonary artery (BPA) SMCs. BPA-SMC expressed ninefold less ACE mRNA than BPA endothelial cells, and threefold less than HuSV -SMCs. Apparent amounts of ACE mRNA were 118,350 +/- 2,300 copier in H uSV-SMCs and 42,200 +/- 11,300 copies in BPASMCs per microgram of tota l cell RNA. The accuracy of the absolute values Is subject to the limi tations of the assumptions used to calculate them. There data support the hypothesis that components of the renin-angiotensin system are tra nscribed by SMCs.