Disease relevance of Pygm

• To this end, we constructed a replication-defective, recombinant adenovirus containing the muscle glycogen phosphorylase cDNA (termed AdCMV-MGP) and used this system to infect hepatocytes in culture [1].
• The possibility of deficient myophosphorylase playing one of the important roles in the pathogenesis of cardiomyopathy is stressed [2].

High impact information on Pygm

• Adenovirus-mediated transfer of the muscle glycogen phosphorylase gene into hepatocytes confers altered regulation of glycogen metabolism [1].
• Muscle glycogen phosphorylase, which contains pyridoxal phosphate, was not affected by dietary pyridoxine [3].
• Regulation of the rat muscle glycogen phosphorylase-encoding gene during muscle cell development [4].
• We now report that amylin caused a dose-dependent increase in activity of muscle glycogen phosphorylase in isolated rat soleus muscle by stimulating phosphorylase a [5].
• We identified age-dependent post-translational modifications of skeletal muscle glycogen phosphorylase b (Ph-b), isolated from F1 hybrids of Fisher 344xBrown Norway rats [6].

Chemical compound and disease context of Pygm

• Absence of myophosphorylase in ethanol induced cardiomyopathy [2].

Biological context of Pygm

• 5. Treatment of the sciatic nerve with 0.40% (w/v) VIN for 1 hr reduced axonal transport and decreased MGP transcript levels by 50% within 7 days, but also reduced sensory and motor nerve conduction velocities and depressed TA contractile function [7].
• These data suggest that muscle activity has an important influence on MGP gene expression [7].
• 3. In Wistar rat liver and skeletal muscle glycogen phosphorylase was activated soon after death and the activity of phosphorylase a remained well above the zero-time level at all later time points, even when the rate of glycogenolysis had slowed significantly [8].

Anatomical context of Pygm

• Daily injection of 2 microg TTX into the sciatic nerve for 7 days eliminated muscle contractile activity and reduced MGP transcript levels by 60% [7].
• The enzyme myophosphorylase is found to be decreased progressively on the basis of histochemical stain in the myocardium of chronically ethanol intoxicated rats [2].

Associations of Pygm with chemical compounds

• It is suggested that the particular susceptibility of fast glycolytic fibres to atrophy as a result of steroid treatment may be linked to: 1 the relatively severe reduction of myophosphorylase activity in these fibres and 2 their comparative inability to utilize alternative energy sources, especially substrates derived from free fatty acids [9].
• Age-associated tyrosine nitration of rat skeletal muscle glycogen phosphorylase b: characterization by HPLC-nanoelectrospray-Tandem mass spectrometry [6].

Analytical, diagnostic and therapeutic context of Pygm

• Comparative sequence analysis of rat, rabbit, and human muscle glycogen phosphorylase cDNAs [10].
• Steady-state transcript levels of the skeletal muscle isozyme of MGP decrease significantly following muscle denervation and after prolonged muscle inactivity with an intact motor nerve [7].
• 4. A single, 1-hr application of 0.10% (w/v) VIN to the sciatic nerve reduced axonal transport but did not alter MGP transcript levels in the associated TA, 7 days after treatment [7].
• Intrinsic myogenic factors, however, also play a role in MGP expression, since denervation did not reduce MGP transcript levels below 30% of control TA [7].
• As a first step toward elucidating such a function, we studied the localization of phosphorylase kinase in glial and neuronal primary cell cultures, and in adult rat brain slices, using a rabbit polyclonal antibody against skeletal muscle glycogen phosphorylase kinase [11].

References