The effect of Ghrelin on activation of UCP3 and phosphorylation of ACC under the high fat environment in rat myoblast / 中国医师杂志

ObjectiveTo study the effect of Ghrelin on activation of UCP3 and phosphorylation of ACC under the high fat environment in rat myoblast,and to support the study on prevention of type 2 diabetes.MethodsThe rat myoblast were exposed to 0.3 mmol/L palmitic acid for 12 h,at the same time,10-11 mol/L,10-9 mol/L,10-7 mol/L Ghrelin were added.The expression of UCP3 mRNA was determined by RT-PCR.The protein levels of UCP3 and p-ACC were measured by western blotting.ResultsCompared with the control group,UCP3 mRNA and the protein levels of UCP3 and p-ACC were obviously decreased in 0.3 mmol/L PA group(UCP3 mRNA:P =0.000,UCP3 protein levels:P =0.000,p-ACC protein levels:P =0.003).Compared with the 0.3 mmol/L PA group,with the increasing concentration of Ghrelin,UCP3 mRNA and the protein levels of UCP3 and p-ACC were elevated.The effects of 10-7 mol/L Ghrelin were significant(UCP3 mRNA:P =0.017,UCP3 protein levels:P =0.000,p-ACC protein levels:P =0.007).ConclusionsGhrelin could enhance activation of UCP3 and phosphorylation of ACC under high fat environment in rat myoblast.

Effect of pH on Binding of Purine Nudeotides to Uncoupling Protein in Subnitochondrial Parti-cles from Rat Brown Adipose Tissue / 第二军医大学学报

Using submitochondrial particles, from rat brown adipose tissue mitochondria treated by Lubrol and 3 mol/L urea, as a model, the relationship between different pH and pKd of binding of purine nucleotides to uncoupling protein was estimated. When it was shown as plots of pKd against pH, it was found that the pKd peak of binding of GDP or ADP to uncoupling protein was about pH 5.5. The greater pH deviated, the less pKd became. The highest pKd of binding of GTP or ATP to uncoupling protein was also near pH 5.5, below which pKd remained constant, but above which pKd dropped rapidly. At a certain pH, pKd of binding of GDP or GTP to uncoupling protein was higher than that of binding of ADP or ATP, respectively.

Binding of Purine Nucleotides to Brown Adipose Tissue Uncoupling Protein from Different Kinds of Animals / 第二军医大学学报

Using brown adipose tissue submitochondrial particles from different kinds of animals, binding of uncoupling protein to different purine nucleotides was estimated. The results indicate that the dissociate constants (Kds) of uncoupling protein from hamsters to purine nucleotides are more than the Kds of uncoupling protein from guinea pigs, which are more than the Kds of that from rats, presumably because of different amino acid residue sequences of uncoupling protein polypeptide from different kinds of animals.