Mitochondrial oxidative enzyme activity in individual fibre types in hypo- and hyperthyroid rat skeletal muscles.

Abstract

Quantitative cytochemical and biochemical techniques have been used in combination to study the response of mitochondrial oxidative enzymes in individual muscle fibre types to hypo- and hyperthyroidism. Hypothyroidism resulted in decreased activity of succinate dehydrogenase (SDH), L-glycerol-3-phosphate dehydrogenase (L-GPDH), and D-3-hydroxybutyrate dehydrogenase (D-HBDH) in all fibre types of both slow-twitch soleus and fast-twitch extensor digitorum longus (e.d.l.) muscles. In hyperthyroidism, only L-GPDH activity increased in e.d.l. but more marked increases were seen in soleus muscles, which also showed increased SDH activity. In addition to these alterations in the enzyme activity in individual fibre types the metabolic profile of the muscle is further modified by the hormone-induced interconversion of slow- to fast-twitch fibres and vice versa.

• Authors: M A Johnson, D M Turnbull
• Journal: Quarterly journal of experimental physiology (Cambridge, England) (Q J Exp Physiol) Vol. 69 Issue 2 Pg. 257-70 (Apr 1984) ISSN: 0144-8757 [Print] England
• PMID: 6729016 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Glycerolphosphate Dehydrogenase
• Hydroxybutyrate Dehydrogenase
• Succinate Dehydrogenase

Topics

• Animals
• Densitometry
• Glycerolphosphate Dehydrogenase (metabolism)
• Hydroxybutyrate Dehydrogenase (metabolism)
• Hyperthyroidism (enzymology)
• Hypothyroidism (enzymology)
• Male
• Mitochondria, Muscle (enzymology)
• Oxidation-Reduction
• Rats
• Rats, Inbred Strains
• Succinate Dehydrogenase (metabolism)