metabolic effect of partial lipectomy in old aged rats and the associated changes in the anti -atherogenic index: adiponectin/leptin ratio

ABSTRACT

The function of adipose tissue deteriorates with aging, but adipose tissue beside its energy storing ability it acts as a sink for free fatty acids. Thereafter, the present study tried to evaluate the outcome of lipectomy with aging, a maneuver widely used now as liposuction, taking in consideration the conflicting effects of Adiponectin and Leptin on the atherogenic changes. Aged-24 month, male, albino rats were divided into two main groups according to the duration after lipectomy [Group-I, one week and Group II, 6 weeks]. Each group included sham-operated control group and lipectomized group. Rats in all groups were subjected for determination of daily food consumption, body weight changes and absolute and relative weight of perirenal fat and liver. Also determination of total Cholesterol, total triglycerides, HDL-c and LDL-c, atherogenic index, blood glucose level and serum levels of Adiponectin and Leptin were done. Then, Adiponectin/ Leptin ratio was calculated. In group I, one week after lipectomy despite of the increase in food intake, the body weight did not increase and the weights of perirenal fat and liver was non-significantly differ from that of control. Also there were significant decrease in TG, LDL-c and atherogenic index as well as non-significant increase in HDL-c. Adiponectin level was increased significantly while Leptin level was decreased significantly with a subsequent significant increase in anti atherogenic index [Adiponectin/leptin ratio]. In addition, blood glucose level was significantly decreased. In group II, six weeks after lipectomy, the food consumption increased in first 3 weeks but it gradually decreased in last three weeks. However, the final body weight as well as the perirenal fat body weight ratio was non-significantly differing from their controls and there was no reaccumulation of fat at the sites of lipectomy. The weight of liver showed significant increase. The levels of TG, TC, and LDL-C, all were increased compared to both their control and to one week lipectomized group. The atherogenic index showed significant increase compared to one week lipectomized group. Leptin was significantly increased and the anti -atherogenic index was significantly decreased compared to one week lipectomized group. The early anti-atherogenic response following lipectomy could be attributed to the increased Adiponectin/ Leptin ratio. The defective fat tissue regeneration due to aging which is suggested to become more worse by lipectomy as well as the reduced anti atherogenic ratio due late increase in Leptin and reduced Adiponectin all, may explain the late worse atherogenic response. Thus, aged person is in need to deal carefully with lipectomy [or other maneuver like liposuction] as fat in their diet may be directed towards their blood vessel wall and /or other tissue as the liver