July - September 2010, Volume 6, Issue 3

Ciortea R

Additive effect of melatonin to estradiol upon visceral fat mass in ovariectomized rats

Acta Endo (Buc) 2010, 6 (3): 315-326
doi: 10.4183/aeb.2010.315

Background. Intraabdominal obesity is considered a low level chronic proinflammatory state. The adipocyte is the central element that integrates multiple metabolic and endocrine signals.\r\nObjectives. This study monitors the metabolic effects of the administration of melatonin or melatonin associated with estrogen in surgically castrated female rats.\r\nMaterial and method. Experiments were performed in white female Wistar rats, with a weight of 160-200 g. At 14 days postovariectomy, a time period required for the postoperative validation of ovarian failure, with the experimental induction of artificial\r\nmenopause in the studied animals, estrogen replacement treatment and combined treatment of estrogen and melatonin were initiated. The duration of the administered treatment, with the products and the doses recommended for veterinary use, was of 12 consecutive weeks.\r\nResults. Food consumption (p=0.60), glycemia (p=0.053) and TG (p=0.34) did not significantly differ between the groups. The comparison of weight and intra-retroperitoneal\r\nfat between the groups in the last week showed that groups which did not receive estrogen had a significantly higher weight and higher intra-retroperitoneal fat than groups to which estrogen was administered (p<0.001). Groups which received estrogen associated with melatonin had a lower weight and a lower intra-retroperitoneal fat compared to groups, which received estrogen alone (p<0.001). Melatonin administred alone (without estrogens)does not show any effects on weight or lipid metabolism in ovarectomised rats.\r\nConclusion. In ovarectomised rats, the associated administration of estrogen and melatonin is correlated with: a less important increase in the body weight, under the conditions of unchanged food consumption, a decrease in intra-retroperitoneal fat, a decrease in total cholesterol, an increase in HDL-cholesterol levels.

Keywords: melatonin, rats, metabolic effects, estrogens

Correspondence: Razvan Ciortea MD, Iuliu Hatieganu UMF - Obstetric Gynecology, B-dul 21 Decembrie Nr 55, 400124 Cluj-Napoca, Romania, Tel:+40748030897, Fax: +40264-599447,\r\nEmail: r_ciortea@yahoo.com