S. Leena et al., Studies on the effect of growth hormone in vivo and in vitro on lipogenic enzymes and transaminases in a teleost Anabas testudineus (Bloch)., ENDOCRINE R, 25(3-4), 1999, pp. 341-355
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.