Effects of hypoxia and thyroid hormone on mRNA levels and activity of phosphoglycerate mutase in rabbit tissues.

OBJECTIVE

In the present work, we studied the effects of hypoxia and triiodothyronine (T(3)) on phosphoglycerate mutase (PGAM) activity and expression in rabbit liver, brain, and skeletal muscle under in vivo conditions.

METHODS

Hypoxia was induced in a methacrylate cage with a mixture of 90% nitrogen and 10% oxygen. Hyperthyroidism was induced daily by T(3) injection (250 microg/kg).

RESULTS

Hypoxia increases the PGAM activity in liver and brain, tissues which possess type PGAM-BB isozyme, but does not affect the PGAM activity in muscle which possesses type PGAM-MM isozyme. T(3) administration increases the PGAM activity in muscle and liver, but does not affect the enzyme activity in the brain. In all cases, the activity changes in parallel with those of PGAM mRNA levels.

CONCLUSIONS

The tissue-specific effects of hypoxia and T(3) could be explained by the tissue-specific distribution of both PGAM isozyme and T(3) receptors.