Inhibition of cPKCβII restored endothelial function. A, the FK506-induced decrease in aortic endothelium-dependent relaxation responses was prevented by the cPKCβII isoform-specific peptide inhibitor, whereas the cPKCβI isoform-specific peptide inhibitor had no effect. B, the cPKCγ isoform-specific peptide inhibitor had no effect on the FK506-induced decrease in aortic endothelium-dependent relaxation responses, whereas inhibition of all cPKC isoforms increased relaxation responses. *, p < 0.05. The numbers of aortas are given in parentheses.