Effect of Various Mixtures of Diethylether, Halothane, Nitrous Oxide and Oxygen on Low Molecular Weight Iron Content and Mitochondrial Function of the Rat Myocardium

Anaesthetic drugs can induce reversible as well as irreversible changes in cell membranes and intracellular proteins as well as lipid peroxidation in the liver. Low molecular weight iron species (LMWI) can by their catalytic activity contribute to the generation of free radicals (hydroxyl radicals). Free radicals are a recognisable cause of intracellular damage. Impaired mitochondrial function is also a sign of intracellular damage, which is usually irreversible. Thus, an agent may be cytotoxic when it causes a significant increase in intracellular LMWI. Whether the LMWI arise from ferritin or is released from iron containing proteins, the same reaction occurs. As long as LMWI can undergo redox cycling, hydroxyl radicals can be formed. We investigated the effect of various mixtures of diethylether, halothane, nitrous oxide and oxygen on the intracellular LMWI content and mitochondrial function of the rat myocardium.

Hearts isolated from rats anaesthetised with diethylether showed an increase in the cytosolic LMWI compared to the control group. No increase in mitochondrial LMWI was demonstrated. Subsequent perfusion of the isolated hearts showed a further increase in the LMWI. On perfusion the mitochondrial LMWI increased in comparison with controls. Mitochondrial function was significantly impaired as measured by the QO₂ (state 3), ADP/O ratio and oxidative phosphorylation rate (OPR).

Exposure of rats to 50% nitrous oxide for 15 minutes increased the myocardial LMWI, but had no effect on mitochondrial function. Exposure to room air for 30 minutes before isolating the hearts, still showed a significant increase in LMWI with no detectable change in mitochondrial function.

Halothane, on the other hand, did not have an effect on the myocardial LMWI and mitochondrial function in the experiment setup used. We therefore concluded that diethylether and nitrous oxide are potentially toxic to the myocardium and may potentiate the action of free radicals.     

The metabolism of inhibitor of flowering and prostaglandin biosynthesis, acetylsalicylic acid, in Pharbitis nil cotyledons

Acetylsalicylic acid, which applied to cotyledons of the short day plant Pharbitis nil prior to an inductive 16-h dark period inhibits flowering by 90 %, is converted to salicylic acid and to a lesser extent to gentisic acid in the cotyledons during this 16-h dark period. Our results confirmed that salicylic acid and gentisic acid are responsible for the inhibition of flowering. They also inhibit prostaglandin biosynthesis. This revised version was published online in July 2006 with corrections to the Cover Date.     

Draft De Novo Genome Sequence of Agapornis roseicollis for Application in Avian Breeding

In aviculture, lovebirds are considered one of the most popular birds to keep. This African parakeet is known for its range of plumage colors and ease to tame. Plumage variation is the most important price-determining trait of these birds, and also the main selection criterion for breeders. Currently, no genetic screening tests for traits of economic importance or to confirm pedigree data are available for any of the nine lovebird species. As a starting point to develop these tests, the de novo genome of Agapornis roseicollis (rosy-faced lovebird) was sequenced, assembled, and annotated. Sequencing was done on the Illumina HiSeq 2000 platform and the assembly was performed using SOAPdenovo v2.04. The genome was found to be 1.1?Gb in size and 16,044 genes were identified and annotated. This compared well with other previously sequenced avian genomes, such as the chicken, zebra finch, and budgerigar. To assess genome completeness, the number of benchmarking universal single-copy orthologs were identified in the genome. This was compared to other previously assembled avian genomes and the results indicated that the genome will be useful in the development of genetic screening tests to aid lovebird breeders in selecting breeding pairs.