Gene expression analysis using semi-quantitative RT-PCR. (A) Semi–quantitative RT-PCR for quantification of renin, ACE and OPN mRNA in respective rats kidney tissue. The ethidium bromide stained gels were scanned using Bio-Rad Gel Doc XR and the intensity of PCR product was quantified using Image Lab Software version 5 (Bio-Rad). The final band intensity for OPN, ACE and renin were expressed relative to the reference gene GAPDH. The expression levels in the control group were considered the basal levels, and the others are expressed as fold change from the control group. (B) The fold change values represent the means ± S.E.M. of (n = 6) in the bar diagram. I, II, III, IV and V represent the respective rat groups.