Fig. 1. Oxidative stress and hepatic PTP oxidation.

(a) 8 week-old male C57BL/6 mice were chow- or HFF for 24 weeks. Blood GSH and GSSG levels and GSH:GSSG ratios were determined. (b) Hepatocytes from 12-week chow- or HFF mice were either left untreated or serum-starved and stimulated with 100 nM insulin for 30 min and H₂O₂ production measured. (c, e-f) Livers from 24 week chow- or HFF mice were processed for an assessment of total PTP oxidation by (c) immunoblot analysis with the PTPox antibody, or (e) mass spectrometry determining relative PTP oxidation (PTP-SO₃H), or (f) processed for immunoblot analysis for the indicated PTPs. (d) Hepatocytes were processed immediately after isolation for an assessment of total PTP oxidation. In (c-d) arrows correspond to TCPTP. Results are means ± SEM for the indicated number of mice (a, e-f) or experimental repeats (b).