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Biomedical subjects

W Davison

Publications and source records attributed to W Davison.

53 records · Page 3Linked to original sources
PubMed1978

The effect of training on the swimming muscles of the goldfish (Carassius auratus).

Goldfish (Carassius auratus) were exercised continuously for periods of 28 days at swimming speeds of 1.5, 3.0 and 4.5 body lengths per second and their rates of growth were determined. Changes in muscle fibre size were examined, as were changes which occurred in the concentrations of the major chemical constituents of these cells. These fish, typical of the carp family in that they are found only in still or slowly moving water, did not adapt well to the flowing water environment at any swimming speed. They often grew less than the controls, although consuming much more food. Changes in the composition of the muscle fibres indicated that excess food was not being stored, and also indicated that the major fuel for swimming at all speeds was glycogen. The fish survived well at high speeds and it was suggested that this was due to the ability of the species to metabolize glycogen anaerobically without the production of lactic acid.

Animals↗
PubMed1977

Further studies on the adaptation of fish myofibrillar ATPases to different cell temperatures.

Previous studies on fish Mg2+Ca2+ activated myofibrillar ATPases have been extended to species inhabiting diverse thermal environments. Cold adapted ATPases have considerably higher catalytic centred activities at low temperatures than warm adapted ATPases. Differences in cell temperature have also lead to evolutionary modifications in thermodynamic activation parameters. The free energies (deltaG2+), enthalpies (deltaH2+) and entropies (deltaS2+) of activation of the Mg2+Ca2+ myofibrillar ATPase are positively correlated with adaptation temperature. Myofibrils with CaATP-2 as substrate in the absence of Mg2+ will hydrolyse ATP by a mechanism not associated with fibril shortening. Differences in activation enthalpies (deltaHH) between cold and warm adapted Ca2+-activated myofibrillar ATPases are less pronounced than for the physiological ATPase. Furthermore the Ca2+-activated ATPase showed no relationship between environmental temperature and substrate turnover number or free energy of activation (deltaG2+).

Acclimatization↗