OXIDATION OF PYRUVATE‐2‐C14, AND LACTATE DEHYDROGENASE ACTIVITY AND ISOENZYME DISTRIBUTION OF FIVE PORCINE MUSCLES

Publisher Website
Google Scholar
Abstract
SUMMARY: A study was conducted to compare parameters of aerobic and anaerobic metabolism in light and dark porcine muscles. Muscle samples were obtained from six Hampshire‐Yorkshire gilts and frozen in liquid nitrogen five min post‐exsanguination. Oxidative metabolism was estimated by measuring the conversion of pyruvate‐2‐C14 to C14O2 in homogenates. The lactate dehydrogenase (LDH) activity of each of the five isoenzymes, separated electrophoretically on cellulose acetate, was ascertained as a measure of anaerobic metabolism. Comparison of the pyruvate oxidation data suggested the following ranking, from most to least aerobic: trapezius, gluteus medius, dark biceps femoris, light biceps femoris, longissimus dorsi, dark semitendinosus and light semitendinosus. Variance analysis of the data indicated trapezius exhibited greater capacity to oxidize pyruvate than all other muscles (P <.05) and gluteus medius and dark biceps femoris exceeded the light semitendinosus (P < .05). LDH comparison among the muscles revealed that light muscles displayed higher (P < .05) activity than dark muscles (trapezius, dark biceps femoris and dark semitendinosus). The results implicated high lactate dehydrogenase activity‐particularly the muscle‐type isoenzyme‐as a factor contributing to rapid postmortem lactate accumulation in light muscles of some porcine animals.