Effects of intraperitoneal gibberelic acid (GA3) on IGF-1 and growth hormone (GH) in the rats
Berna Afacan, Nuray Erin, Özkan Ulusoy & Mustafa Kemal Balci
Plant growth factors are used commonly in agriculture. The effect of these factors on human health is unknown. Gibberellins are the most commonly used growth factors that have the structure of Diterpenoid acid. One of the gibberellins (GA3) induces tumor formation in mice but the mechanism of action is not known. We here examined changes in levels of GH and IGF-1 and examined whether there is a correlation between growth factors levels and weight changes.
Male Wistar Albino rats were used and all the injections were made i.p. We had five experimental groups. Single high dose of GA3 was given to group 1 (20 mg/kg); Single injection of solvent was given to group 2; 2 mg/kg GA3 was given to group 3 for 30 days; 20 mg/kg GA3 was given to group 4 for 30 days and lastly solvent of GA3 was injected to group 5 for 30 days.
At the end of the experiment, levels of GH and IGF-1was measured in serum, liver and kidney. Although GH and IGF-1 levels were not changed in the serum, GH levels in liver was decreased significantly in group 1 (P<0.05). IGF-1 levels in liver decreased in group 3, but this effect was returned to control levels in group 4. In renal tissue IGF-1 levels decreased in group 1 (P<0.05), but increased significantly in group 3 and 4 (P<0.05). Weight of the animals increased significantly in group 3 compared to group 5 only at the second week, while it increased continuously (P<0.05) in group 4 compared to group 5. This is the first report demonstrating that GA3 alters GH and IGF-1 levels.