Glycolytic, Pentose‐Phosphate Shunt and Transaminase Enzymes in Gastrocnemius Muscle, Liver, Heart, and Brain of Two Mouse Mutants, 129 J‐dy and A2G‐adr, with Abnormal Muscle Function

Abstract

Aldolase and phosphoglycerate kinase activity were markedly reduced in muscle from two mouse mutants, 129 J-dy and A2G-adr, with abnormal muscle development. The pentose-phosphate shunt enzymes, glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase, were both greatly increased in the gastrocnemius of 129 J-dy mice, but only the former was slightly increased in A2G-adr muscle. Alanine and aspartate aminotransferase activities were normal or low in 129 J-dy muscle but increased to approximately 200% in A2G-adr muscle. Liver from 129 J-dy mice showed increased activity of glucose-6-phosphate dehydrogenase. These findings are compatible with the well-recognised lipid involvement in the 129 J-dy mutant but indicate that an abnormality of amino acid metabolism in relation to energy supply is probably more important in the A2G-adr mutant.

Developmental Changes in Lactate Dehydrogenase and Aldolase Activity of the A2G‐adr Mouse with Abnormal Muscle Function: Further Comparison with the 129Re‐dy Mutant

“…The results show clearly that at all ages investigated the adr mutation in A2G mice is expressed in the white muscle fibres but not the red. They also confirm an earlier report that aldolase activity is decreased in the gastrocnemius of adult adrladr mice while brain, heart, and liver are unaffected (Soothill et al, 1981).…”

“…Of the organs studied, only liver showed a change in activity with age, being lower at 2 weeks (0.03 -t 0.005) than in the adult (0.18 2 0.005; p < 0.001). As reported previously (Soothill et al, 1981), levels in the adrladr liver, heart, and brain were similar to those found in controls. In the 129Re strain, aldolase activity of the dyldy lateral gastrocnemius (0.59 * 0.06) was significantly less than normal (0.70 * 0.03; p < 0.001).…”

“…The Bar Harbor 129Re-dy "dystrophic" mouse first described by Michelson et al (1955) is an autosomal mutant which is also characterised by progressive muscle weakness and atrophy which has been said to resemble human dystrophia myotonica (Mcintyre et al, 1959). Soothill et al (1981) have compared glycolytic, pentose phosphate shunt, and transaminase enzymes in the gastrocnemius muscle, liver, heart, and brain in these two mutants. They found de-518 W .…”

Gastrocnemius Muscle Lipids in Relation to Diet in Two Mouse Mutants, 129Re‐dy and A2G‐adr, with Abnormal Muscle Function

“…The dy and adr strains show remarkable similarities in the distribution of individual PLs; however, the characteristic increase in neutral lipids was observed only in the dy strains. This pathological level of total lipids correlates well with the severity of dystrophy in the d y mutant and may also relate to the increased activity of the pentose shunt, which is characteristic of the d y but not of the A2G muscle (Soothill et al, 1981).…”

“…Changes in dy membrane PLs, however, cannot be specifically attributed to either fiber type. In the A2G-adr mutant, other biochemical changes seem to be particularly associated with the type I1 fibres and the histochemistry suggests only a minor lipid involvement (Watkins, 1978;Soothill et al, 1981). Numerous biochemical studies have been carried out on hereditary muscular dystrophy of the mouse but the fundamental defect is still obscure.…”