The effect of renal perfusion pressure on renal vascular resistance in the spontaneously hypertensive rat

Renal hemodynamics and renal vascular resistance (RVR) were measured in the spontaneously hypertensive rat (SHR) and in the normotensive Wistar-Kyoto rat (WKY). In addition, the autoregulatory response and segmental RVR in the SHR were studied after aortic constriction. Mean arterial pressure (MAP) and RVR were higher in the SHR than in the WKY, but renal blood flow (RBF) and glomerular filtration rate were similar in both groups. Measurement of mean afferent arteriolar diameter (AAD) by a microsphere method showed a significantly smaller AAD in SHR (17.7±0.35 μm) than in the WKY (19.5±0.20 μm). This decrease in AAD could account for a 47% increase in preglomerular resistance. Aortic constriction in the SHR, sufficient to reduce renal perfusion pressure from 152 to 115 mm Hg, did not alter the AAD. Since RBF and glomerular filtration were also well maintained following aortic constriction, these autoregulatory responses suggest that vessels proximal to the afferent arteriole rather than postglomerular vasculature are primarily involved in the changes on intrarenal vascular resistance in SHR.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47448/1/424_2004_Article_BF00581421.pd

Synthesis, crystallographic and spectroscopic studies, evaluation as antimicrobial and cytotoxic agents of a novel mixed-ligand nickel(II) complex

<p>A new mononuclear mixed-ligand complex of Ni(II) has been synthesized and structurally characterized by single-crystal X-ray diffraction as [Ni(4-Cl-pydc)(apym)(H₂O)₂], where 4-Cl-pydc and apym are 4-chloropyridine-26-dicarboxylate and 2-aminopyrimidine, respectively. Spectroscopic studies such as FT-IR, UV-vis, ¹H-NMR, and thermal analysis (TGA/DTA) were carried out. The fluorescence properties were studied in solvents with different dipole moments. Antimicrobial activities of 4-chloropyridine-26-dicarboxylic acid (<b>1</b>), 2-aminopyrimidine (<b>2</b>), complex (<b>3</b>), and nickel(II) nitrate hexahydrate (<b>4</b>) were investigated by disk diffusion and broth microdilution methods against three Gram-positive bacteria, <i>Staphylococcus aureus</i>, <i>Bacillus subtilis</i>, <i>Staphylococcus epidermidis</i> and three Gram-negative bacteria, <i>Escherichia coli</i>, <i>Pseudomonas aeruginosa</i>, <i>S. marcescens</i>; also antifungal effect was evaluated on <i>Aspergillus niger</i> and <i>Saccharomyces cerevisiae in vitro</i>. The highest antibacterial activity of complex was observed nearly equal to gentamicin as a standard drug toward <i>S. epidermids</i> with IZD of 18 mm. The <i>in vitro</i> antiproliferative activity of <b>1–4</b> on H1299 (a human non-small cell lung carcinoma), HepG2 (a human liver hepatocellular carcinoma), and β-TC3 (a mouse beta pancreatic) cell lines was evaluated by MTT (3-(45-dimethylthiazol-2-yl)-25-diphenyl-2H-tetrazolium bromide) assay and, effect of complex on depolarization of mitochondrial membrane (MMP) of all three cell lines was measured by rhodamine 123. The highest cytotoxic effect of complex was exhibited toward H1299 cell line with IC₅₀ value equal to 10 μM.</p