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Biomedical subjects

G Goldspink

Publications and source records attributed to G Goldspink.

At least 127 records · Page 7Linked to original sources
PubMed1975

Effects of severe energy and protein deficiencies on the fibres and nuclei in skeletal muscle of pigs.

1. Measurements have been made of the size and number of muscle fibres and number of nuclei in a small indicator muscle (m. flexor digiti V brevis) in the fore-foot of the pig. Well-nourished, 10-d-old and 1-year-old animals were studied, as well as 1- and 2-year-old animals that were severely energy-deficient and protein-deficient. 2. The normal 1-year-old animals had much larger muscle fibres, with more nuclei, than the pigs in any of the other groups. 3. There were no significant differences between the numbers of fibres in the muscles of pigs in any of the four groups. 4. There was a significant difference between the number of fibres in the muscles of pigs coming from different litters, irrespective of their dietary history after birth. This suggests that the number of fibres is determined genetically before birth, and all that can take place after birth is an alteration in size.

Age Factors↗
PubMed1974

Effect of denervation on the adaptation of sarcomere number and muscle extensibility to the functional length of the muscle.

1. The effects of denervation on the response of the cat soleus muscle to immobilization at different lengths by plaster casts has been investigated for a period of 4 weeks.2. The passive length-tension properties of the denervated immobilized muscles were not significantly different from those of non-denervated muscles. Muscles immobilized in the shortened position showed a marked decrease in extensibility whether they were denervated or not. In all the other cases the length-tension curves were not significantly differetn from those of normal muscles.3. The denervated soleus muscle immobilized in the lengthened position was found to produce 25% more sarcomeres in series, whilst those immobilized in the shortened position lost 35%. This adaptation was essentially the same as in muscles that had been immobilized but not denervated.4. Denervation was found to have no effect on the recovery of muscles that had been subjected to 4 weeks immobilization in the shortened position. In these muscles the sarcomere increased back to the normal level within 4 weeks after removal of the plaster cast.5. The adjustment of sarcomere number to the functional length of the muscles does not therefore seem to be directly under neuronal control. It appears to be a myogenic response to the amount of passive tension the muscle is subjected to.

Animals↗
PubMed1974

Work-induced hypertrophy in exercised normal muscles of different ages and the reversibility of hypertrophy after cessation of exercise.

1. Groups of male hamsters of different ages were subjected to a weight-lifting exercise regimen, and the biceps brachii, soleus and extensor digitorum longus (EDL) muscles examined for structural changes occurring in response to the increased workload. In addition, two groups of adult hamsters were left to recover from the exercise stimulus for 5 and 15 weeks respectively.2. All the exercised muscles exhibited muscle fibre hypertrophy, and the extent of the hypertrophy was greater in the younger animals. In all age groups, the biceps brachii and EDL showed more hypertrophy than did the soleus. There was no significant increase in fibre number after exercise.3. In both groups allowed to recover from the exercise stimulus, the fibre dimensions reverted back to those of the control muscles; this appeared to be complete after 15 weeks recovery.4. Electron microscopical studies of fibres from exercised and control biceps brachii revealed no significant changes with exercise in the proportions present of myofibrillar, mitochondrial and tubular components within muscle fibres of the same size.

Age Factors↗
PubMed1973

The effects of environmental temperature on the properties of myofibrillar adenosine triphosphatase from various species of fish.

1. Myofibrillar adenosine triphosphatase (ATPase) activities were measured for white myotomal muscle of 19 species of fish. 2. The activity was measured at different temperatures and after periods of preincubation at 37 degrees C. 3. The inactivation half-life at 37 degrees C depended on environmental temperature, increasing as the temperature increased. 4. Cold-water fish had higher myofibrillar adenosine triphosphatase activity at low temperatures than had warm-water fish. 5. The significance of these results is discussed.

Adenosine Triphosphatases↗