Bradykinin can enhance skeletal muscle glucose uptake (GU), and exercise increases both br adykinin production and muscle insulin sensitivity, but bradykinin’s relationship with post-exercise insulin action is uncertain. Our primary aim was to determine if the B2 receptor of bradykinin (B2R) is essential for the post- exercise increase in GU by insulin-stimulated mouse soleus muscles. Wildtype (WT) and B2 R knockout (B2RKO) mice were sedentary or performed 60 minutes of treadmill exercise. Isolated soleus muscles were incubated with [ 3 H]-2-deoxyglucose ±insulin (60 or 100 μ U/ml). GU tended to be greater for WT vs. B2RKO soleus with 60 μ U/ml insulin (P=0.166) and was significantly greater for muscles with 100 μ U/ml insulin (P<0.05). Both genotypes had significant exercise-induced reductions (P<0.05) in glycemia and insulinemia, and the decrements for glucose (~14 %) and insulin (~55 %) were similar between genotypes. GU tended to be greater for exercised vs. sedentary soleus with 60 μ U/ml insulin (P=0.063) and wa s significantly greater for muscles with 100 μ U/ml insulin (P<0.05). There were no significant interactions between genotype and exercise for blood glucose, plasma insulin or GU. These results indicate that the B2R is not essential for the exerci se-induced decrements in blood glucose or plasma insulin or for the post-exercise increase in GU by insulin-stimulated mouse soleus muscle., G. G. Schweitzer ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
We explored the effect of chronically elevated circulating levels of growth hormone (GH)/insulin -like -growth- factor-1 (IGF-1) on mRNA expression of GH/IGF-1/insulin axis components and p85alpha subunit of phosphoinositide -3-kinase (p85alpha) in subcutaneous adipose tissue (SCAT) of patients with active acromegaly and compared these findings with healthy control subjects in order to find its possible relationships with insulin resistance and body composition changes. Acromegaly group had significantly decreased percenta ge of truncal and whole body fat and increased homeostasis model assessment-insulin resistance (HOMA -IR). In SCAT, patients with acromegaly had significantly increased IGF-1 and IGF -binding protein-3 (IGFBP-3) expression that both positively correlated wit h serum GH. P85alpha expression in SCAT did not differ from control group. IGF-1 and IGFBP-3 expression in SCAT were not independently associated with percentage of truncal and whole body fat or with HOMA -IR while IGFBP -3 expression in SCAT was an independ ent predictor of insulin receptor as well as of p85alpha expression in SCAT. Our data suggest that GH overproduction in acromegaly group increases IGF-1 and IGFBP-3 expression in SCAT while it does not affect SCAT p85alpha expression. Increased IGF-1 or IGFBP-3 in SCAT of acromegaly group do not appear to contribute to systemic differences in insulin sensitivity but may have local regulatory effects in SCAT of patients with acromegaly., V. Touskova, J. Klouckova, V. Durovcova, Z. Lacinova, P. Kavalkova, P. Trachta, M. Kosak, M. Mraz, D. Haluzikova, V. Hana, J. Marek, M. Krsek, M. Haluzik., and Obsahuje bibliografii
The skin matrix metalloproteinase 3, tissue inhibitors of matrix metalloproteinase 2 and collagen III content changes in type 1 diabetes and insulin resistance treated with insulin a nd metformin were studied. Healthy adult male Wistar rats were obtained from experimental animal house, Department of Experimental Pharmacology, Medical University in Bialystok. The rats were divided randomly into five groups of 8 rats each. Control rats were injected intraperitoneally by NaCl. Type IDDM was induced by a single injection of Streptozocin. Insulin resistance was induced by a high -fat diet. The chosen groups of rats were also treated with insulin or metformin. ELISA K its (USCN Life Science, China) were used to measure content of matrix metallo - proteinase 3 (ELISA Kit for Matrix Metalloproteinase 3 - MMP3), tissue inhibitor of matrix metalloproteinase 2 (ELISA Kit for Tissue Inhibitors of Metalloproteinase 2 - TIMP2) and content of collagen type 3 (ELISA Kit for Collagen Type III - COL3). The results were reported as a median. The statistical significance was defined as p<0.05. Type 1 diabetes and insulin resistance have significantly reduced the quality of the skin, shown by the increase in cont ent of matrix metalloproteinase 3 and the decrease in content of tissue inhibitors of matrix metalloproteinase 2. Type 1 diabetes and insulin resistance have reduced the quality of the skin expressed by type III collagen content decrease but for future studies it is recommend to determine rat interstitial collagenase, MMP -13, as well. Insulin and metformin treatment improved the quality of the diabetic skin, demonstrated by the type III collagen content increase., M. Knaś, K. Wołosik, A. Zalewska, A. Mikucka-Niczyporuk, I. Kasacka, M. Niczyporuk., and Obsahuje bibliografii
Spontaneously hypertensive rats (SHR/NIH strain) harbor a deletion variant in the Cd36 fatty acid transporter and display defective fatty acid metabolism, insulin resistance and hypertension. Transgenic rescue of Cd36 in SHR ameliorates insulin resistance and improves dyslipidemia. However, the role of Cd36 in blood pressure regulation remains controversial due to inconsistent blood pressure effects that were observed with transgenic expression of Cd36 on the SHR background. In the current studies, we developed two new SHR transgenic lines, which express wild type Cd36 under the control of the universal Ef-1 promoter, and examined the effects of transgenic expression of wild type Cd36 on selected metabolic and cardiovascular phenotypes. Transgenic expression of Cd36 in the new lines was associated with significantly decreased serum fatty acids, amelioration of insulin resistance and glucose intolerance but failed to induce any consistent changes in blood pressure as measured by radiotelemetry. The current findings confirm the genetic association of defective Cd36 with disordered insulin action and fatty acid metabolism in the SHR/NIH strain and suggest that Cd36 is linked to other gene(s) on rat chromosome 4 that regulate blood pressure., M. Pravenec, V. Landa, V. Zídek, A. Musilová, L. Kazdová, N. Qi, J. Wang, E. St.Lezin, T. W. Kurtz., and Obsahuje bibliografii