Endocrine Abstracts

Objectives-Aim: Oxidized low-density lipoprotein (LDL) seems to play an important role in the etiology of atherosclerosis. They stumulate atherosclerosis. Oestradiol and other oestrogens have been shown to be powerful antioxidants in vitro when they are added to ldl oxidation mixtures. Oestrogen deficiency states are increases LDL oxidation. The aim of this study is investigate the effect of growth hormone on LDL oxidation in estrogen deficiency.

Materials- Methods: Overectomized Sprague-dawley rats used to study the effects of growth hormone. Sprague-Dawley rats were ovariectomized at 120-140 days of age. Twelve weeks after ovariectomy these rats are divided into two groups. While GH therapy is (Genotropin, 7.5 mg/kg/gay for 4 weeks.) applied to one of the groups (GHT), the other group wasn't given any treatment (OVX). The oxidizability of LDL by determining the levels of Malonaldehyde bis(dimethyacetyl) (MDA) and diene conjugation were determined at baseline LDL oxidation and compared compared among normal, OVX and GHT gruoups. It was used Mann Whitney U test for statistical analysis (SPSS 8,0 for Windows) and p <0.05 values were accepted as significantly.

Results: It was shown that LDL oxidation increased by estrogen deficiency. The MDA values of osteoporotic rats were significantly higher than normal rats (p=0.002). While dienes value was 167.83 ± 29.04 nmol/mg protein and MDA values was 0.518 ± 0.163 nmol/gr in the OVX group, dienes was 119.50 ± 16.76 nmol/mg protein and MDA was found 0.275 ± 0.04 nmol/gr in the GHT group (p= 0.03 for dienes and p= 0.019 for MDA). These data have shown that growth hormone therapy is effective on decrease of LDL oxidation

Conclusion: In this study, use of growth hormone at dosage of 7.5 mg/kg/day. decrease LDL oxidation induced by oestrogen deficiency