A histochemical and biochemical study of phosphorylase and glycogen synthetase in smooth muscle

✍ Scribed by Bo, Walter J. ;Smith, Mavis S.

• Publisher: John Wiley and Sons
• Year: 1965
• Tongue: English
• Weight: 850 KB
• Volume: 153
• Category: Article
• ISSN: 0003-276X
• DOI: 10.1002/ar.1091530309

✦ Synopsis

Phosphorylase and UDPG-glycogen synthetase were studied in the smooth muscle of the urinary bladder, large intestine, skeletal muscle (adductors of thigh), and esophagus of the adult male and female rat. The two enzymes were investigated by histochemical and biochemical procedures.

In the skeletal muscle of the thigh and esophagus, UDPG-glycogen synthetase was not as strong as phosphorylase. The latter enzyme was strong in the smooth muscle cells of the urinary bladder and large intestine. The response was better in the inner circular than in the outer longitudinal layer of the large intestine. Only phosphorylase was detected in the muscularis mucosa of the esophagus and large intestine. UDPG-glycogen synthetase activity varied from a good response to a very weak one in the smooth muscle cells of the urinary bladder and large intestine. In the latter organ the response was stronger in the inner circular than in the outer longitudinal layer. From the biochemical studies phosphorylase and UDPG-glycogen synthetase were determined to be present in significant amounts in the urinary bladder, large intestine, and skeletal muscle of the thigh.

Since significant amounts of the enzymes are present in smooth muscle, glycogen may be synthesized from UDPG by the action of UDPG-glycogen synthetase, while phosphorylase is concerned with the breakdown of glycogen to G-I-P. However, more information on the relationship of the enzyme to glycogen concentration in smooth muscle is needed. 1 The investigation was supported by USPHS grant AM-08029. zThe authors wish to thank Dr. Warren Dannenbur Department of Obstetrics and Gynecology. for his %elpful suggestions during the investigation.