Scientific Endeavours

This project attempted to test the glutathione-s-transferases of antarctic fish species with a variety of xenobiotic substrates. The substrates chosen were 1-chloro-2, 4-dinitrobenzene, 2,4-dichloro-1-nitrobenzene, p-nitrobenzly chloride and page 18 cumene hydroperoxide. To test for these enzymes fish had to be caught, their livers excised and homogenised, then lightly centrifuged and assayed spectrophotometrically. All work was based at Scott Base and fish were caught in the Cape Armitage area.

Attempts were made to separate the two enzyme systems that break down cumen hydroperoxide; glutathione-s-transferase and selenium dependent glutathione peroxidase. These were unsuccessful as the yield of enzyme from initial purification procedures was too low.

It was possible to repeat the work attempted in the 1983/84 programme where results gained were affected by instrument errors. This gave significantly higher enzyme activity in accordance with that found in frozen samples in New Zealand. The effect of freezing on the glutathione-s-transferases and cumen peroxidase activity were examined as well as the thermal stability of the enzyme in crude homogenates.

Frozen liver samples of antarctic fish species were brought back to New Zealand for further research.