Influence of pressure overload and ACE inhibitor therapy on constitutive protein mRNA expression in the spontaneously hypertensive rat.
Despite use as constitutive protein standards to quantify mRNA, data are limited regarding alteration of cyclophilin or glyceraldehyde-3-phosphate dehydrogenase (G3PDH) in hypertension or angiotensin converting enzyme (ACE) inhibitor treatment. We assessed these standards in 6 month old Wistar-Kyoto rats (WKY, n = 16), compared to age-matched spontaneously hypertensive rats (SHR, n = 14). Additional SHR (n = 8) had received enalapril for 3 to 4 months at evaluation. Left ventricular (LV) and kidney RNA was extracted for dot blot cyclophilin and G3PDH cDNA hybridization. Cyclophilin and G3PDH mRNA densitometries were expressed as a ratio. Cyclophilin/G3PDH for the WKY, untreated SHR, and enalapril SHR were 1.56 +/- 0.33, 1.45 +/- 0.42, and 1.49 +/- 0.51, respectively, for the LV, and 1.52 +/- 0.09, 1.43 +/- 0.22, and 1.38 +/- 0.22, respectively, for the kidney. Differences were not significant. Relative expression of cyclophilin/G3PDH was unaffected by genetic SHR hypertension, or long term enalapril. Thus, either constitutive mRNA may be confidently used to index structural or functional protein responses, at the transcriptional level, in the SHR.