Calcitonin gene-related peptide-1 (CGRP-1) is a potent regulator of glycogen metabolism in rat skeletal muscle.
We investigated the effects of CGRP on glucose metabolism in intact rat skeletal muscle preparations that are largely composed of either type I (soleus) or II fibres (e.g. extensor digitorum longus (EDL) or epitrochlearis muscles). CGRP-1 inhibited insulin-stimulated glycogen synthesis in both soleus and EDL muscle preparations. Rat CGRP-1 was a potent stimulator of glycogenolysis only in muscles composed of type II fibres, which depend on high rates of glycogenolysis to produce high power outputs. These results may provide the basis for understanding how CGRP regulate glycogenolysis in type II fibres in vivo.
Leighton
B
B
Department of Biochemistry, University of Oxford, England.
Foot
E A
EA
Cooper
G G
GG
King
J M
JM
D000818:Animals; D015740:Calcitonin Gene-Related Peptide; D000242:Cyclic AMP / Q000032:analysis; D004305:Dose-Response Relationship, Drug; D006003:Glycogen / Q000096:biosynthesis / Q000378:metabolism*; D066298:In Vitro Techniques; D007328:Insulin / Q000494:pharmacology; D007773:Lactates / Q000096:biosynthesis; D008297:Male; D009132:Muscles / Q000187:drug effects / Q000378:metabolism*; D009479:Neuropeptides / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D007328:Insulin; D007773:Lactates; D009479:Neuropeptides; D006003:Glycogen; D000242:Cyclic AMP; D015740:Calcitonin Gene-Related Peptide