Particulate preparations from mammalian heart which are able to transfer electrons in successive steps from reduced diphosphopyridine nucleotide (DPNH) to molecular oxygen or to intermediate components of the respiratory chain have been reported from time to time (1, 2). Likewise, lipid-free, soluble DPNH dehydrogenases have been obtained from sarcosomal particles. Among them, the diaphorase of...

The distribution of nitric oxide synthase was investigated in human cerebral blood vessels and brain tissues. NADPH-diaphorase histochemistry, which is a marker for nitric oxide synthase in neurons and endothelial cells, revealed periadventitial nerve fibers in the arteries of the circle of Willis and their cortical branches, as well as the common carotid and subclavian arteries. The fibers wer...

Resistance of hypoxic tumor cells to ionizing radiation and cytotoxic drugs has been attributed to changes in the reacUvity and/or the half times of reactive species in the altered redox environment. Exposure of eukaryotic cells to such hypoxic conditions results in the induction of the synthesis of several unrelated proteins. To Investigate further the phe nomenon of hypoxic cell resistance to...

Nitric oxide (NO) is a membrane-permeant signaling molecule which activates soluble guanylyl cyclase and leads to the formation of cyclic GMP (cGMP). The NO/cGMP signaling system is thought to play essential roles during the development of vertebrate and invertebrate animals. Here, we analyzed the cellular expression of this signaling pathway during the development of the Drosophila melanogaste...

Metal toxicity is a threat mainly in the industrialised world where industry discharges many toxic metals into the environment. We investigated the effects of two metals – cadmium and selenium – on the cytosolic antioxidant enzymes and esterases in the liver, kidneys and testes of rats. Male Sprague-Dawley rats (n=28) were divided equally into four groups: control, cadmium, selenium and cadmium...

The cytochemical localization, by conventional methods, of lactate and glyceraldehyde-3-phosphate dehydrogenases is limited, firstly, by the solubility of these enzymes in aqueous media and, secondly, by the dependence of the final electron flow from reduced nicotinamide-adenine dinucleotide (NADH) to the tetrazolium on tissue diaphorase activity: localization is therefore that of the diaphoras...

3alpha-Hydroxysteroid dehydrogenase (3alpha-HSD) from Pseudomonas testosteronei and diaphorase (lipoyl dehydrogenase) from Clostridium spp were immobilized individually onto alkylamine glass beads through glutaraldehyde coupling. A cost-effective enzymic colorimetric method for determination of bile acid in the serum and bile was developed employing mixture of the immobilized enzymes. The metho...