ABSTRACT
A recombinant peptide Pro-Pro-[Arg11]hPTH(1-34)-Pro-Pro, was designed, biosynthesized, and purified in our lab (generated by substituting Arg for Leu at position 11 and adding -Pro-Pro to the carboxyl terminus of hPTH(1-34)-peptide), and reported to be capable of enhancing serum calcium level in chicken. In this investigation, we studied its impact on the structure, component, and biomechanical properties of rat bones. The pharmacological effect of Pro-Pro-[Arg11]hPTH(1-34)-Pro-Pro was investigated to evaluate its therapeutic potential for the treatment of osteoporosis, one of the most prevalent and rapidly spreading diseases in the world. 3-month-old normal female rats were sham-ovariectomized or ovariectomized, then fed for 14 weeks. Small doses of Pro-Pro-[Arg11]hPTH(1-34)-Pro-Pro were given to the rats afterward (daily subcutaneous injection of 0.4-0.9nmol/100g body weight for 16 weeks). Values of various parameters, including the body weight, the bone mass, the bone geometry, the bone biomechanics, the bone histology, the bone histomorphology, and the serum biochemistry, were collected before or after animal sacrifice. Daily subcutaneous injection of Pro-Pro-[Arg11]hPTH(1-34)-Pro-Pro induced 37.0-42.4% increase in vertebral BMD, 28.5-47.9% increase in femoral BMD, 30.7-43.7% decrease in marrow cavity or increase in trabecular bone area. The peptide also increased calcium, phosphorus, and collagen in bone by 52.1-59.7%, 24.5-34.7%, and 26.3-28.0%, respectively. In terms of mechanic properties, peptide administration elevated bone rigidity by 55.7-84.5%, decreased the deflection by 14.8-26.7%, and improved modulus of elasticity by 28.1-76.4%. These data suggest Pro-Pro-[Arg11]hPTH(1-34)-Pro-Pro has a positive effect on bone mass accumulation and microstructure improvement, fortifies bone strength, and possesses anti-aging capability, which may merit further investigation.
Subject(s)
Ovariectomy/adverse effects , Parathyroid Hormone/chemistry , Peptide Fragments/pharmacology , Recombinant Proteins/chemistry , Alkaline Phosphatase/metabolism , Animals , Biomechanical Phenomena/drug effects , Body Weight/drug effects , Bone Density/drug effects , Calcium/blood , Female , Femur/drug effects , Femur/pathology , Femur/physiopathology , Humans , Organ Size/drug effects , Osteocalcin/blood , Osteoporosis, Postmenopausal/drug therapy , Peptide Fragments/chemistry , Peptide Fragments/therapeutic use , Phosphorus/blood , Rats , Rats, Sprague-DawleyABSTRACT
Ideal blood glucose control requires accurate insulin injections under the guidance of frequent glucose monitoring.Artificial pancreas (AP),the closed-loop control system can adjust the input amount of insulin automatically with the body's blood glucose levels.The AP allows diabetics to control blood glucose ideal,then get the benefit of prevention of complications and bring convenience and safety in clinical application.Accuracy is the key issue of the AP.To improve the accuracy of such a system need to improve the detection accuracy and reliability,increase speed and accuracy of the output control,and improve the accuracy of the system regulation model.
ABSTRACT
To investigate the impact of exercise on the expression of adiponectin and GLUT4 mR NA in type 2 diabetic rats, type 2 diabetic rat model was made. The diabetic rats were treated with swimming training for 8 weeks. The expression of adiponectin mRNA in perirenal fat and GLUT4mRNA in skeletal muscles were assessed by reverse transcription polymerase chain reaction (RT PCR) and the levels of blood glucose, serum insulin, and blood lipid were measured. Our results showed that the expression of adiponectin mRNA and GLUT4 mRNA in diabetic model group was decreased by 45 % (P＜0.01), 43 % (P＜0.01) respectively. The gene expression of adiponectin and GLUT4 was increased significantly in swimming group (P＜0.05 and P＜0.01, respectively).Compared with the model group, fasting insulin, TG, TC and FFA were decreased significantly in the training group (P＜0.05 or P＜0.01) as compared with model group. It is concluded that exercise can promote the expression of adiponectin mRNA and GLUT4 mRNA in type 2 diabetic rats,which may be one of the mechanisms responsible for the amelioration of insulin resistance in the rats.
