Free Radical Enhancer Xenobiotic is an Inducer of Cataract in Rabbit

Free radical enhancers, diquat, paraquat, plumbagin and juglone were used to study the oxy radical-induced damage to the rabbit lens in vitro and in vivo. Each compound caused a 6–8 fold increase in malondialdehyde (MDA) and a 30–55% decrease in reduced glutathione of the lens in vim. These peroxidative and oxidative changes were potentiated in the presence of 100% 0., abolished by N, and prevented by desferal-Mn (III) (DF-Mn) or liposomal superoxide dismutase (LSOD) indicating the involvement of O₂^?.

Diquat injected intravitreally as a single dose (300nmole in 30μl of isotonic saline) in the right eye of a 5-wk-old Dutch belted rabbit, induced early cataract after 24–72h. The lens of the contralateral control eye injected with isotonic saline had no change. In the right eye, O₂,^? and OH -productions were significantly (P < 0.01) higher; O₂-, was about 16 fold higher in the aqueous humor and vitreous humor, and 5 fold in the lens and retina, and OH. was 35 fold higher in the aqueous humor, 2 fold in vitreous humor and 5 fold in the lens and retina as compared to the respective tissues of the control eye. Enhanced lipid peroxidation in the lens was apparent from the higher levels of MDA and formation of aminophospholipid-MDA Schiff-base conjugates.

We propose that cyclic oxidation-reduction of xenobiotics coupled to the endogenous redox systems in the eye, could generate oxy radicals in excessive amounts, triggering cataractogcnesis.     

Circular Thin-layer Chromatography of Oligosaccharides

The physicochemical properties and chemical constituents of the blue protein from rice bran were investigated. The blue protein was a copper-containing glycoprotein, the molecular weight of which was found to be 18,300 Daltons by the sedimentation equilibrium method assuming the partial specific volume 0.72 cm³ g^?1. The hexose and pentose contents were 5.49 and 4.01 g per 100 g protein respectively. The copper content was 0.38% which corresponded to 1.09 atoms per one molecule of the protein. The electron spin resonance spectrum showed that the copper was in a cupric state. The standard oxidation-reduction potential of the copper was found to be +275 mV at 20°C and at pH 7.39. The visible and near infrared absorption maxima were found at 450, 600 and 890 mμ, and the 450 mμ band was optically active in the optical rotatory dispersion exhibiting a large Cotton effect.     

High-performance liquid chromatography (HPLC) determination of inosine,a potential biomarker for initial cardiac ischaemia,using isolated mouse hearts

Abstract

Each year in the USA approximately 7–8 million patients with non-traumatic chest pain come to hospital emergency rooms. It is estimated that approximately 2–5% of these patients are experiencing cardiac ischaemia, but due to the shortcomings of the available testing methods they are incorrectly diagnosed and discharged without appropriate therapy having been provided. Preliminary data with a globally ischaemic mouse heart model has demonstrated that endogenous inosine might be a potential biomarker of initial cardiac ischaemia before cardiac tissue necrosis. A high-performance liquid chromatographic diode array detection (HPLC-DAD) method was utilized for the detection and quantification of inosine in Krebs–Henseleit (Krebs) buffer solution perfusing from surgically removed and isolated mouse hearts undergoing global cardiac ischaemia. A C₁₈ column at a flow rate of 0.6 ml min^?1 with an aqueous mobile phase of trifluoroacetic acid (0.05% trifluoroacetic acid in deionized water, pH 2.2, v/v) and methanol gradient was used for component separation. The assay detection limit for inosine in Krebs buffer solution was 500 ng ml^?1 using a 100-µl neat injection. The HPLC results were used to determine total cardiac effluxed inosine into the Krebs effluent for each mouse during oxidative stress and compared with the per cent cardiac ventricular functional recovery rate to determine if a relationship exists amongst this cardiovascular parameter during periods of cardiac oxidative stress.     

NAADP-induced intracellular calcium ion is mediated by the TPCs (two-pore channels) in hypoxia-induced pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a form of obstructive vascular disease. Chronic hypoxic exposure leads to excessive proliferation of pulmonary arterial smooth muscle cells and pulmonary arterial endothelial cells. This condition can potentially be aggravated by [Ca²⁺] _i mobilization. In the present study, hypoxia exposure of rat's model was established. Two-pore segment channels (TPCs) silencing was achieved in rats' models by injecting Lsh-TPC1 or Lsh-TPC2. The effects of TPC1/2 silencing on PAH were evaluated by H&E staining detecting pulmonary artery wall thickness and ELISA assay kit detecting NAADP concentrations in lung tissues. TPC1/2 silencing was achieved in PASMCs and PAECs, and cell proliferation was detected by MTT and BrdU incorporation assays. As the results shown, NAADP-activated [Ca²⁺]_i shows to be mediated via two-pore segment channels (TPCs) in PASMCs, with TPC1 being the dominant subtype. NAADP generation and TPC1/2 mRNA and protein levels were elevated in the hypoxia-induced rat PAH model; NAADP was positively correlated with TPC1 and TPC2 expression, respectively. In vivo, Lsh-TPC1 or Lsh-TPC2 infection significantly improved the mean pulmonary artery pressure and PAH morphology. In vitro, TPC1 silencing inhibited NAADP-AM-induced PASMC proliferation and [Ca²⁺]_i in PASMCs, whereas TPC2 silencing had minor effects during this process; TPC2 silencing attenuated NAADP-AM- induced [Ca²⁺]_i and ECM in endothelial cells, whereas TPC1 silencing barely ensued any physiological changes. In conclusion, TPC1/2 might provide a unifying mechanism within pulmonary arterial hypertension, which can potentially be regarded as a therapeutic target.     

The Drosophila Platelet-derived Growth Factor and Vascular Endothelial Growth Factor-Receptor Related (Pvr) Protein Ligands Pvf2 and Pvf3 Control Hemocyte Viability and Invasive Migration

Vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) family members are essential and evolutionary conserved determinants of blood cell development and dispersal. In addition, VEGFs are integral to vascular growth and permeability with detrimental contributions to ischemic diseases and metastatic cancers. The PDGF/VEGF-receptor related (Pvr) protein is implicated in the migration and trophic maintenance of macrophage-like hemocytes in Drosophila melanogaster embryos. pvr mutants have a depleted hemocyte population and a breakdown in hemocyte distribution. Previous studies suggested redundant functions for the Pvr ligands, Pvf2 and Pvf3 in the regulation of hemocyte migration, proliferation, and size. However, the precise roles that Pvf2 and Pvf3 play in hematopoiesis remain unclear due to the lack of available mutants. To determine Pvf2 and Pvf3 functions in vivo, we generated a genomic deletion that simultaneously disrupts Pvf2 and Pvf3. From our studies, we identified contributions of Pvf2 and Pvf3 to the Pvr trophic maintenance of hemocytes. Furthermore, we uncovered a novel role for Pvfs in invasive migrations. We showed that Pvf2 and Pvf3 are not required for the directed migration of hemocytes, but act locally in epithelial cells to coordinate trans-epithelial migration of hemocytes. Our findings redefine Pvf roles in hemocyte migration and highlight novel Pvf roles in hemocyte invasive migration. These new parallels between the Pvr and PDGF/VEGF pathways extend the utility of the Drosophila embryonic system to dissect physiological and pathological roles of PDGF/VEGF-like growth factors.     

Simplicissin,a New Pollen Growth Inhibitor Produced by the Fungus,Penicillium cf. simplidssimum (Oudemans) Thorn No. 410

A new pollen growth inhibitor, named simplicissin, was isolated from Penicillium cf. simplicissimum (Oudemans) Thorn No. 410, and its structure was established by spectroscopic methods including 2D NMR. The biological activities of the compound were examined by the bioassay methods involving tea pollen together with lettuce seedlings. The compound inhibited the growth of the tea pollen tube by 45% at a concentration of 3 mg/liter and showed complete inhibition at 10mg/liter.