| Calcium plays an important role in the body fat metabolism, study indicates that dietary calcium has an anti-obesity role in fat mechanism, People think that dietary calcium absorded into body will change the intracellular calcium concentration. so that changes in calcium signals trigger a series of biological effects.We know, calcium stores can increase the intracellular calcium concentration by IP3 path and make calcium signaling change. The current study about changes in intracellular calcium concentration mainly focused on muscle contraction and cardiovascular diseases and so on, few people studies on fat metabolism on changes in intracellular calcium concentration by IP3 path.this research is to study with obesity and normal mice, treated with norepinephrine, heparin, Calcium-carbonate and norepinephrine+Calcium carbonate, heparin+Calcium carbonate. This research needed to record body weight, feed intake, tissue weight, Serum lipid levels, Tissue calcium content, lipid metabolism-related genes mRNA and protein expression. So this research aimed to investigate that what changes in intracellular calcium concertration by dietary calcium and calcium stores have on fat metabolism. he main results are as follows:1. In obesity mice,we found:the body weight and fat tissue were weighed, total cholesterol (TC), triglycerides(TG) and high density lipop rotein cholesterol(HDL-C) were measured,the calcium concentration of epididymal fat, perirenal fat and liver were measured, and the expression levels of two major transcriptional factors PPARγand C/EBPαas well as lipolytic gene HSL,lipogenic gene FAS and IP3 receptor IP3R1 mRNA were measured by RT-PCR. The results showed dietary calcium and heparin on the obese mice have significant weight loss and body fat gain decreasing(P<0.01), the concent rations of TG and TC in blood serum decreased significantly(P<0.01), and that of HDL-C increased significantly(P<0.01). the expression levels of PPARγ, FAS and IP3R1 mRNA was downregulated(P<0.01), C/EBPαmRNA levels were not significant changes,while the expression level of HSL mRNA increased significantly(P<0.01). NE alone had a significant weight gain on mice(P<0.01). Dietary calcium have significant weight loss(P<0.01), norepinephrine+ Calcium carbonate have more weight loss(P<0.01), Calcium carbonate,heparin+Calcium carbonate have litter weight loss(P<0.01). IP3 pathway activation can increase intracellular calcium and fat accumulation; on the other hand, IP3 pathway suppression reduce fat accumulation. Through the IP3 pathway, dietary calcium can inhibit the increase in intracellular calcium.2. In obesity mice, we found:all inhibited body weight of normal mice(P<0.01), decreased epididymal fat and perirenal fat weight(P<0.01), Increased brown adipose tissue weight (P<0.01), serum TG and TC were significantly lower (P<0.01), but HDL-C level was increased (P<0.01). NE could increase the expression of IP3R1 (P<0.01), Heparin inhibited the expression of IP3R1 (P<0.01). The mice were treated by NE, heparin and dietary calcium, their FAS, PPARγand C/EBPαshowed a significant decrease (P<0.01), HSL expression increased significantly (P<0.01). The PPARγ, C/EBPαand FAS protein content decreased in NE group,heparin group,calcium group, NE+Calcium group and heparin+calcium group, The ATGL protein content increased in NE group, heparin group, Calcium group, NE+Calcium group and heparin+Calcium group In short, IP3 pathway that calcium can promote lipolysis. While NE increased intracellular calcium,it could promote lipolysis, there may be other ways to explain the impact of fat metabolism in mice, brown adipose tissue maybe played an important role, its heat production significantly consume excess body fat, reduced fat deposition in normal mice. |
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