Factors affecting tissue growth

Cairney, James F (1972) Factors affecting tissue growth. MSc(R) thesis, University of Glasgow.

Abstract

A study has been undertaken of various factors which affect the growth of tissue. It has been known for over a century that, when one of the kidneys of a laboratory animal or of a human being is diseased or has been surgically removed, its partner undergoes compensatory growth. This phenomenon is termed compensatory renal hypertrophy and has been used as the basic experimental model in the present investigation. The index of growth used in these studies was sometimes total renal weight, or total renal weight relative to body weight and on other occasions kidney composition was estimated by making use of the fact that in the kidney the DNA content per cell is constant. An estimation of the DNA content of the kidney, therefore, will give an indication of the number of cells, present, and by relating other cellular constituents to DNA, an indication can be obtained of the average cell composition. Some experiments were also performed in vitro using adult rat kidney cells aggregating on micropore filters and forming a biochemically viable colony; in these experiments growth was estimated by assay of the incorporation of radioactive isotope into DNA, RNA and protein. It has been shown that the correlation between total renal weight and rat body weight is not particularly good, whereas that between liver weight and rat body weight is good; the correlation between the dry weight of the kidneys and rat body weight is fairly good as is that between the dry weight of the liver and body weight. The best correlation between the various parameters is that between the dry weight of the kidneys and the weight of the liver. In seeking the stimulus to the compensatory growth which occurs after removal of one kidney, changes in the physiological and biochemical state of the rat have been investigated after unilateral nephrectomy. In fact, very little change occurs in the more important physiological and biochemical parameters following unilateral nephrectomy. There is no alteration in plasma sodium levels in the first 48 hours after unilateral nephrectomy in the rat when compared to sham operated animals. Both nephrectomized and sham operated rats have an elevated pH 16 hours after unilateral nephrectomy; the indications are that this occurs as a result of hyperventilation causing loss of CO?. Plasma amino acid analysis has shown a reversal of the normal glutamine/glutamate ratio with a marked fall in the plasma glutamine level and a corresponding increase in the plasma glutamate level; this is present only at 14 hours after unilateral nephrectomy. There is no consistent alteration in the blood ammonia level in the first 48 hours after unilateral nephrectomy. There is no significant increase in the amidotransferase activity of the remaining kidney 48 hours after unilateral nephrectomy. However, there is a suspicion that sham operation depresses the level of kidney amidotransferase activity. Unilateral nephrectomy causes no immediate alteration in the level of arterial blood pressure. Thus, there is little indication of what might be the stimulus to compensatory renal hypertrophy. Growth of the kidney might theoretically be modified by various dietary and parenteral means . (Abstract shortened by ProQuest.).

• Item Type: Thesis (MSc(R))
• Qualification Level: Masters
• Additional Information: Adviser: R Y Thomson
• Keywords: Physiology
• Date of Award: 1972
• Depositing User: Enlighten Team
• Unique ID: glathesis:1972-73084
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 14 Jun 2019 08:56
• Last Modified: 14 Jun 2019 08:56
• URI: https://theses.gla.ac.uk/id/eprint/73084