Regulation of forskolin-induced cAMP production by cytochrome P450 epoxygenase metabolites of arachidonic acid in HEK293 cells

Introduction  

Cytochrome P450 epoxygenases metabolize arachidonic acid to epoxyeicosatrienoic acids (EETs), which in turn are converted to dihydroxyeicosatrienoic acids (DHETs) by soluble epoxide hydrolase (sEH). EETs are known to modulate a number of vascular and renal functions, but the exact signaling mechanism(s) of these EET-mediated effects remains unknown.     

On the mechanism of malonyl-CoA-independent fatty-acid synthesis. Different properties of the mitochondrial chain elongation and enoylCoA reductase in various tissues.

1. NADPH-specific mitochondrial enoyl-CoA reductase can be assayed by a sensitive radioactive test, employing tritium-labelled NADPH, synthesized in a prefixed reaction from D-[1-3H]-glucose via the hexokinase and glucose-6-phosphate dehydrogenase reactions. 2. Liver, kidney cortex, heart muscle, skeletal muscle, brown adipose tissue, brain cortex, and aortic intimal tissue are investigated concerning chain lengths specificity of the chain elongation and the enoyl-CoA reductase. Medium-chain acyl-CoA compounds prove to be the best primers for the chain elongation. Enoyl-CoA reductases still show large incorporation rates with hexadecenoyl-CoA. 3. The differences in the chain lengths specificity of the chain elongation and enoyl-CoA reductase can be explained by the inhibitory effect of long-chain acyl-CoA derivatives on the 3-hydroxyacyl-CoA dehydrogenase. 4. The nucleotide specificity in the different tissues reveals two types of chain elongation: In addition to liver and kidney cortex, mitochondria of brown adipose tissue need NADH + NADPH for optimal chain elongation, whereas heart muscle, skeletal muscle and aortic intimal mitochondria only need NADH. 5. Different physiological roles are proposed for the two types. The "heart type" may be of importance in the conservation of reducing equivalents or acetate units in the anaerobic state, the "liver type" may play a role in the transfer of hydrogen from NADPH to the respiratory chain. In addition, the mitochondrial chain elongation may serve as bypass of the first part of the respiratory chain.     

Heavy metal concentrations in,and human health risk assessment of,three commercially valuable fish species in the lower Niger River,Nigeria

The concentrations of Fe, Mn, Ni, Pb and V in water, sediment and the gill, liver and muscle tissues of Synodontis resupinatus, Heterotis niloticus and Clarias gariepinus, all commercially important fish species of the lower Niger River, were investigated in 2015. Water, sediment and fish samples were collected for six months and heavy metals were determined using an Atomic Absorption Spectrometer. Fe ranked highest in water and sediment, with concentrations of 2.74 mg l^?1 and 61.60 mg kg^?1, respectively. Metals followed the magnitude of Fe > Mn > Ni > V > Pb in the water and Fe > Mn > V > Ni > Pb in the sediments. Metal concentrations were higher in the tissues of S. resupinatus compared with H. niloticus and C. gariepinus. Fe was also highest in the gills, liver and muscle of the three fish species. Its highest concentration of 132.97 mg kg^?1 dry weight was recorded in the gills of S. resupinatus. Bioconcentration factors of metals ranged from 8.79 for Mn in H. niloticus muscle to 67.99 for Ni in S. resupinatus gills. The fish species studied pose no health risk for all metals studied, because the target hazard quotient was less than 1 and the estimated daily intakes of the metals were below the reference doses.     

Reranking candidate gene models with cross-species comparison for improved gene prediction

Background  

Most gene finders score candidate gene models with state-based methods, typically HMMs, by combining local properties (coding potential, splice donor and acceptor patterns, etc). Competing models with similar state-based scores may be distinguishable with additional information. In particular, functional and comparative genomics datasets may help to select among competing models of comparable probability by exploiting features likely to be associated with the correct gene models, such as conserved exon/intron structure or protein sequence features.     

Root anatomy of palms III. Ceroxyloideae,Nypoideae, Phytelephantoideae

Summary The root-anatomy of representatives of nine genera of Ceroxyloideae of the eleven genera accepted by UHL & DRANSFIELD (1987), of Nypa, the onliest genus of Nypoideae, and of all three genera of Phytelephantoideae have been studied. In Coryphoideae and Calamoideae every genus can be distinguished by the anatomy of the roots, whereas within one genus the species do not differ but slightly. This is true for the newly examined genera too and contributes both to define and identify the genera and towards an improved understanding of the relationship between genera and subfamilies. The genera of Ceroxyloideae are obviously related, they form a natural group, and even the somewhat isolated Pseudophoenix is well at home here. Both Nypa and Phytelephantoideae do not exhibit any affinities with other palms studied up to now.