Stress-induced proteins in aortic smooth muscle cells and aorta of hypertensive rats

The current studies were performed to determine whether vascular smooth muscle cells produce stress-induced proteins when subjected to experimental hypertension. Two-dimensional gel electrophoresis was used to analyze labeled proteins in cultured cells in response to either heat shock or arsenite treatment. The major heat shock proteins (HSPs) induced had molecular masses of 70, 90, and 100 kDa. Arsenite treatment produced a similar response with the additional induction of a 30-kDa protein. In vitro translations of total RNA from heat-shocked cells, and RNA blot hybridization using HSP 70 cDNA suggested that HSP 70 induction was transcriptionally regulated. Treatment of cells with norepinephrine or angiotensin II induced cellular hypertrophy without eliciting HSPs. In vitro translation of aortic RNA from rats rendered hypertensive by administration of deoxycorticosterone and a high salt intake also did not reveal HSP induction. The absence of HSP induction using an in vivo model of hypertension suggests that those proteins may not be required to mediate the vascular response to experimental hypertension.