L-carnitine attenuates cardiac impairment but not vascular dysfunction in DOCA-salt hypertensive rats

L-Carnitine is an important co-factor in fatty acid metabolism by mitochondria. This study has determined whether oral administration of L-carnitine prevents remodelling and the development of impaired cardiovascular function in deoxycorticosterone acetate (DOCA)-salt hypertensive rats (n = 6–12; #p < 0.05 versus DOCA-salt). Uninephrectomized rats administered DOCA (25 mg every 4th day s.c.) and 1% NaCl in drinking water for 28 days developed cardiovascular remodelling shown as systolic hypertension, left ventricular hypertrophy, increased thoracic aortic and left ventricular wall thickness, increased left ventricular inflammatory cell infiltration together with increased interstitial collagen and increased passive diastolic stiffness and vascular dysfunction with increased plasma malondialdehyde concentrations. Treatment with L-carnitine (1.2% in food; 0.9 mg⁄g⁄day in DOCA-salt rats) decreased blood pressure (DOCA-salt 169 € 2; + L-carnitine 148 € 6# mmHg), decreased left ventricular wet weights (DOCA-salt 3.02 € 0.07; + L-carnitine 2.72 € 0.06# mg⁄ g body-wt), decreased inflammatory cells in the replacement fibrotic areas, reduced left ventricular interstitial collagen content (DOCA-salt 14.4 € 0.2; + L-carnitine 8.7 € 0.5# % area), reduced diastolic stiffness constant (DOCA-salt 26.9 € 0.5; + L-carnitine 23.8 € 0.5# dimensionless) and decreased plasma malondialdehyde concentrations (DOCA-salt 26.9 € 0.8; + L-carnitine 21.2 € 0.4# lmol ⁄ l) without preventing endothelial dysfunction. L-carnitine attenuated the cardiac remodelling and improved cardiac function in DOCA-salt hypertension but produced minimal changes in aortic wall thickness and vascular function. This study suggests that the mitochondrial respiratory chain is a significant source of reactive oxygen species in the heart but less so in the vasculature in DOCA-salt rats, underlying the relatively selective cardiac responses to L-carnitine treatment

Structural characterization of YBa(2)Cu(3)O(7)/Y(2)O(3) composite films

Using 4-circle x-ray diffraction and transmission electron microscopy we have studied the microstructure and in-plane orientation of the phases present in thin film composite mixtures of YBa(2)Cu(3)O(7) and Y(2)O(3). We see a high degree of in-plane orientation and have verified a previous prediction for the in-plane order of Y(2)BaCuO(5) on (110) MgO. Transmission electron microscopy shows the composite films to be a mixture of two phases, with YBCO grain sizes of 1 micron. We have also compared our observations of the in-plane order to the predictions of a modified near coincidence site lattice model.Comment: To be published in Journal of Materials Research, (4 pages, 4 jpeg figures

Cooling of 2 kW H subscript 2-O subscript 2 fuel cell

An extensive research and development program has been carried out to devise an improved method of removing waste heat of reaction from a developmental 2 kW hydrogen-oxygen fuel cell

(Biphenyl-2-yl)bromidobis(2-methyltetrahydrofuran-[kappa]O)magnesium(II)

In the title Grignard reagent, [MgBr(C12H9)(C5H10O)2], the Mg centre adopts a distorted tetrahedral MgCO2Br arrangement. The dihedral angle between the two aromatic rings of the biphenyl residue is 44.00 (14)°. Each molecule incorporates one R- and one S-configured 2-methyltetrahydrofuran molecule. Key indicators: single-crystal X-ray study; T = 173 K; mean &#963;(C–C) = 0.007 Å; R factor = 0.045; wR factor = 0.108; data-to-parameter ratio = 17.4