3,5,3'-triiodothyronine (T3) and 3',5'-diiodothyrone (T2) have short-term effects on lipid metabolism in a teleost Anabas testudineus (Bloch): evidence from enzyme activities.

As thyroid hormones are known to have long-term and short-term effects on metabolism and only the long term effects been examined in detail, in the present investigation a comparative study has been mad to elucidate the short-term effects of T3 and T2 on enzymes of lipid metabolism in a fish Anabas testudineus. The time dependent studies involved assays of specific, activities of lipogenic enzymes and membrane ATPase- Anabas responded to T3 treatment with a significant increase in the liver malic enzyme activity (after 1 hr) and the activity pattern was reversed after 6 hrs in low dose (0.25microg T3) treated group. T2 treatment also increased the malic enzyme activity within one hour after administration. T2 caused an Increase, in the activity of glucose-6-phosphate dehydrogenase under both time courses, HMG-CoA Reductase activity was reduced upon T3 and T2 administration except for T2 at one hour. T3 treatment significantly enhanced Na+K+-ATPase activity while T2 decreased it except by low dose at one hour. Both T3 and T2 treatment influenced the activities of enzymes of lipid synthesis in a dose and time dependent manner emphasising a short-term effect of these thyroid hormones in Anabas.