ACTIVITY OF AMP-REGULATED PROTEIN KINASE AND AMP-DEAMINASE IN THE HEART OF MICE FED HIGH-FAT DIET

AMP-regulated protein kinase (AMPK) is involved in numerous regulatory processes and its role in control of cardiac energy metabolism is particularly important. This activity could be affected by AMP-deaminase (AMPD) since substrate of AMPD is AMPK activator. Hearts of male mouse, fed for six weeks with normal or high-fat diet, were fractionated to enrich AMPK activity. Purified fraction was incubated with AMARA peptide for up to 5 minutes and then conversion of AMARA to pAMARA was determined by liquid chromatography-mass spectrometry (LC/MS) using mass detector. Activity of AMPK in heart was 0.038 +/- 0.012 pmol/min/mg protein for mice fed high-fat diet and that was not different to control (0.032 +/- 0.01 pmol/min/mg protein). We observed change in AMPD activity. It was 5.39 +/- 1.5 nmol/mgtissue/min in heart of mice fed high-fat diet while in heart of mice fed low-fat diet it was 2.29 +/- 0.32 nmol/mgtissue/min. Data we present indicate that while total AMPK activity is not changed decrease in AMPD activity may affect AMPK signaling in diabetic heart.