RT – PCR assay of the expression of the mRNA for endothelial NO synthase (eNOS) in aortae from controls, STZ-diabetic and chronically J-104132-treated STZ-diabetic rats. (a) Expression of the mRNA for eNOS assayed by RT – PCR. (b) Quantitative analysis of expression of the mRNA for eNOS (by scanning densitometry). Control rats (n=7, open column); STZ-induced diabetic rats (n=5, closed column); J-104132-treated diabetic rats (n=6, hatched column). Each column represents the mean±s.e.mean of six determinations (eNOS/GAPDH). The RT – PCR assay was performed as described in Methods. Each total RNA preparation (2.0 μg) was reverse transcribed and half of the cDNA product was PCR-amplified using the appropriate primers, 24 cycles (GAPDH) and 28 cycles (eNOS) being employed. A portion of the PCR reaction product was electrophoresed on a 1.5% agarose gel containing ethiodium bromide.