Enzymatic Studies of Liver Cells Obtained by Fine Needle Biopsy from Mice with the Obese-Hyperglycemic Syndrome (Genesymbol ob)

Abstract

In an enzymatic study of livers from obese hyperglycemic mice (obob) and their lean litter mates, microdissected freezedried fine needle biopsies were used. Carbohydrate, fatty acid and ketone body metabolism was examined through assays of phosphofructokinase (PFK), 3-hydroxyacyl-CoA dehydrogenase (HOADH) and D-3-hydroxybutyrate dehydrogenase (HBDH). At 2 months of age the obob-mice showed a significant increase in PFK activity as compared to their lean litter mates. No such difference was found for the activity of HOADH and HBDH. An early increase in the initial glycolysis in the livers of obob-mice might thus be one of the factors responsible for the accelerated synthesis of lipids resulting in the fatty livers of the adult obob-mice. The present results corroborate previous studies indicating no major derangement in the fatty acid and ketone body metabolism in the livers of obob-mice.

In a methodological evaluation of the technique for tissue sampling and preparation, freeze-dried fine-needle punctates showed significantly higher enzyme activities of PFK and HOADH than freeze-dried liver sections or crude homogenates. Freeze-drying of fine needle biopsies appears to be a technique with good preservation of the enzyme activity. This is of significance for future metabolic studies also in humans.

Key words

obob Mice - Liver - Enzyme Activities - Phosphofructokinase - D-3-Hydroxybutyrate Dehydrogenase - 3-Hydroxyacyl-CoA Dehydrogenase - Fine Needle Aspiration Biopsy