ABSTRACT
Objective: To investigate how fatty liver was developed in ventromedial hypothalamus(VMH)-lesioned obese rats. Methods: Two groups of rats were prepared: (1)VMH-lesioned obese rats, and (2)sham VMH-lesioned rats. One week after VMH lesions, livers of all rats were isolated for morphological observation and for determination of microsomal triglyceride transfer protein(MTP), phosphatidate phyosphohydrolase (PAP), malic enzyme (ME), and glucose-6-phosphate dehydrogenase(G6PDH). Results: Triglyceride contents in livers of VMH-lesoned obese rats increased significantly, and were about 1.8-fold of control group. Activities of ME, G6PDH and PAP in the livers were also enhanced markedly compared to their controls. Many lipid droplets in cytoplasm of hepatocytes from VMH-lesioned obese rats were observed, while there was no similar finding in hepatocytes of control rats. MTP activity in livers of VMH-lesioned obese rats was higher than that in livers of sham-operated non-obese rats [0.201?0.013 vs. 0.175?0.014 ?g/(mg protein?h),[WTBX]P0.05). Conclusion: Hepatic triglyceride production and activity of MTP were increased in VMH-lesioned obese rats, but magnitude of the latter did not exceed the former. This resulted in hepatic triglyceride accumulation in spite of increase in transport of triglyceride out of liver by MTP. This may contribute to the development of fatty liver in VMH-lesioned obese rats.
ABSTRACT
Objective: To investigte the lipogenic and lipolytic metabolism at dynamic phase of obesity in ventromedial hypothalamus-lesioned obese rats. Methods: Female SD rats were divided into two groups, one group received bilateral electrolytic lesions of ventromedial hypothalamus(VMH),and the other one was used as sham control. Samples of blood, livers and subcutaneous, parametric and mesenteric adipose tissues were collected one week after VMH lesions and sham operations. Results: Activities of microsomal triglyceride transfer protein(MTP) in hepatocytes, and phosphatidate phosphohydrolase (PAP), malic enzyme(ME), glucose-6-phosphate dehydrogenase(G6PDH)in liver, parametric and mesenteric adipose tissue in VMH-lesioned rats were increased as compared to their sham counterparts. Activity of hormone sensitive enzyme(HSL) in parametric and mesenteric adipose tissue in VMH-lesioned rats was not changed when compared to sham group. Activity of HSL in subcutaneons adipose tissue was increased, while activity of HSL in gastrocnemius was decreased. Activity of lipoprotein lipase(LPL) in parametric and mesenteric adipose tissue and gastrocnemius were enhanced significantly compared to sham group. Conclusion: In dynamic phase of obesity of VMH-lesioned rats, hepatic production and transportation of triglyceride in these rats were increased significantly ,and lipogenic metabolism and storage of triglyceride in adipose tissues such as parametric and mesenteric adipose tissues were also enhanced.Meanwhile, lipolytic metabolism in subcutaneous adipose tissue and gastrocnemius was also increased.
ABSTRACT
Objective: To investigate the prevalence of overweight and obesity and relation of body mass index (BMI) to body fat percentage and waist circumference in Chinese healthy adults. Methods: 1005 healthy adults were divided into five groups by BMI,which was made by WHO's recent classification of BMI for Asian adults. Anthropometric measurements (waist and hip circumference , skinfold thickness and ratio of waist and hip circumference) and bioelectrical impedance analysis (BIA) were done in subjects. Results: The prevalence of overweight and obesity classⅠin males were significantly higher than in females. The prevalence of obesity classⅡwas lower both in males and in females. Females had higher percent body fat than males measured by BIA and by skinfold thickness measurements. BMI was significantly correlated with waist circumference in all age groups. Waist circumference was more than 80 cm in overweight females, and more than 90 cm in obesity classⅠin males. Conclusion: The age of overweight and obesity in males was younger than in females. The body fat in females was higher than in males. BMI cut off points for obesity diagnosis are over estimated much more than BIA and skinfold thickness measurements for percent body fat in adults. It should be noted that age, sex and physical activity need to be considered besides BMI when obesity is diagnosed.