Surplus Food: Its Effect on Protein Metabolism with Observations on the Metabolic Response to Injury

Cuthbertson, David Paton (1937) Surplus Food: Its Effect on Protein Metabolism with Observations on the Metabolic Response to Injury. PhD thesis, University of Glasgow.

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1. The ingestion of diets very rich in first class protein and of high calorie value, by persons suffering from the fracture of one or more of their long bones as the result of direct violence, modified considerably the marked loss of body protein which normally occurs under such circumstances. At the height of the catabolic disturbance, however, such diets still failed to prevent this loss of protein. 2. The addition of extra carbohydrate to rats which were in receipt of a fractured femur, apparently exercised a sparing effect on tissue protein,which was more marked than that observed in the human subject. The reason for this probably lay in the fact, that a day in the life of a rat is relatively a much longer period of time, than a day in the life of man. It is possible that had analyses been made at more frequent intervals than once every 24 hours, results similar to those found in the human subject might have been obtained. 3. Measures such as massage and manipulation, the addition of meat extractives, glycine, hydrolysate of mixed ox tissue, gelatin and sodium caseinate, and diets of high calorie value but average protein content similarly failed to stem the loss of protein, and generally proved less successful in mitigating the drain on the body's reserves. 4. The catabolic disturbance is characterised by an increase in the basal consumption of oxygen with attendant rise in pulse rate and temperature, and by parallel rises in the urinary output of total N, total S, total P and to a less extent K. Na excretion remains relatively unchanged. 5. The creatinuria which develops and parallels the rise in total N is accompanied by little change in the creatinine excretion; such change as occurred took the form of a slight diminution during the period of maximum creatinuria. 6. If it be assumed that muscle tissue is mainly contributing to this excessive urinary excretion, then the loss of K is relatively greater than the loss of N, and the loss of creatine is relatively smaller than the N loss. 7. Analyses of the quadriceps femoris overlying the fractured femur revealed that there was relatively a greater loss of K than N. The S:N ratio of the excess S and N outputs in the urine was 1:16.36 - a value close to that of muscle. 8. Owing to the fact that the change in weight of the injured limb was relatively insignificant in comparison with the variability of weight found to exist amongst the dissected hind quarters of intact animals, it was impossible to determine whether the introduction of a local anaesthetic with a presumed prolonged action allayed reflex wasting. 9. The loss in weight of the quadriceps femoris of the injured limb was not prevented by forced feeding. This was only to be expected. 10. If it be presumed that the excess N comes from muscle then the loss of muscle substance cannot account for more than two thirds of the total loss of body weight. The presumption is that the reserves of carbohydrate and fat are also called on to meet the demand for readily oxidisable material. 11. Trauma such as has been described also causes, at least in the human subject, an immediate and marked disturbance of the plasma proteins. Both the total amount and relative proportions are affected. The general effect is a slight fall in the albumin moiety coupled with a very definite rise in the globulin fraction. Fibrinogen was often found to be appreciably raised. 12. Subsequent manipulations of the injured part were found to cause a considerable increase in the globulin and fibrinogen fractions, and an increased loss of N was also found in the urine.

Item Type: Thesis (PhD)
Qualification Level: Doctoral
Keywords: Medicine, Physiology
Date of Award: 1937
Depositing User: Enlighten Team
Unique ID: glathesis:1937-80106
Copyright: Copyright of this thesis is held by the author.
Date Deposited: 03 Mar 2020 09:04
Last Modified: 03 Mar 2020 09:04

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