Figure 2.

Stimulation of TGF-β1 is not associated with alteration in the expression of its mRNA. Serum-deprived HK-2 cells were either stimulated with insulin (5 μg/ml), in the absence of serum, or in control experiments 5 mmol/L d-glucose was added in the absence of insulin. RNA was isolated at time points up to 48 hours. RT-PCR was performed and PCR products separated by electrophoresis on a 3% agarose gel (A). Scanning densitometry confirmed the lack of induction of TGF-β1 after addition of insulin. One representative experiment of four individual experiments is shown. After isolation of RNA, TGF-β1 mRNA was also examined by Northern analysis (B).