Studies on the effect of growth hormone in vivo and in vitro on lipogenic enzymes and transaminases in a teleost Anabas testudineus (Bloch).

The specific activities of three lipogenic enzymes, malic enzyme (ME), gluc ose-6- phosphate dehydrogenase (G6PDH) and isocitrate dehydrogenase (ICDH), in liver and heart and two transaminases (AST & ALT) in liver and muscle, were studied in response to the in vivo and in vitro administration of grow th hormone (GH) in a teleost Anabas testudineus. Ovine growth hormone (oGH) in vivo significantly reduced the activities of lipogenic enzymes, except for heart G6PDH, which showed an increase at the highest dose of hormone. T ransaminase activity either increased or decreased depending on the dose of GH. The lowest dose of hormone employed (0.1 mu g/gm b/w) exhibited a stim ulatory effect and the highest dose (0.5 mu square/gm. b/w) an inhibitory e ffect on transaminase activity. Both ovine GH and carp GH (oGH and cGH) in vitro significantly reduced the activities of ME, G6PDH and ICDH. Activitie s of AST and ALT were increased by oGH and cGH in vitro. The present study reveals that irrespective of origin, GH in vitro has a direct inhibitory ef fect on lipogenic enzymes ME, G6PDH, ICDH and a stimulatory effect on trans aminases AST and ALT in A. testudineus, thus favoring gluconeogenesis.