Thyroid hormone stimulates phosphoglycerate mutase activity and isozyme transition in rat muscle tissues.

Triiodothyronine (T3) increases phosphoglycerate mutase (PGAM) specific activity in rat skeletal and cardiac muscles. This increase is concomitant with an increase in the proportion of phosphoglycerate mutase isozymes which contain type-M subunit. Propylthiouracil (PTU), an anti-hormone, not only decreases phosphoglycerate mutase activity with respect to control rats, but also decreases the total M subunit contents. In liver, which only possesses type-B subunit phosphoglycerate mutase, none of the effects were detected.