Angiotensin-converting enzyme (ACE) I/D genotype and renal ACE gene expression

Background. The angiotensin-converting enzyme (ACE) I/D genotype affects se rum ACE levels and the onset and progression of renal disease, but little i s known about the mechanism. We investigated a possible association between the ACE I/D genotype and renal ACE mRNA levels in healthy subjects. Methods. Renal biopsy samples were obtained from 50 healthy kidney donors. The ACE I/D genotype was determined by polymerase chain reaction (PCR). Ren al ACE mRNA quantification was performed by competitive RNA-PCR. In situ hy bridization (ISH) for ACE mRNA on renal biopsy specimens was also performed . Results. The number of ACE transcripts in 100 ng of total RNA was significa ntly (P < 0.01) lower in subjects with II genotype (5.6 +/- 5.3 x 10(5), N = 20) compared with those with the ID (17.9 +/- 13.6 x 10(5), N = 23) or th e DD genotype (36.9 +/- 14.6 x 10(5), N = 7) in healthy donors. The ISH stu dies showed that both tubular and glomerular ACE mRNA expressions were weak in subjects with the II genotype, intermediate in subjects with ID genotyp e, and strong in subjects with DD genotype. Conclusions. It is suggested that renal ACE gene expression is associated w ith the ACE I/D genotype in healthy Japanese subjects.