Chemical aspects of kidney growth

Halliburton, Ian W (1966) Chemical aspects of kidney growth. PhD thesis, University of Glasgow.

Abstract

1. The estimation of kidney hypertrophy has been placed on a more quantitative basis by using the DNA content of the kidney as a measure of the cell number; an indication of the average cell composition has then been obtained by relating the other cellular components to DNA. This approach has been used to compare the hypertrophy following unilateral nephrectomy with the variation in kidney size and composition produced by variations in the diet. In addition, changes in RNA biosynthesis of the remaining kidney have been examined in the first 12 hours after unilateral nephrectomy. 2. In normal rats the right kidney is, on the average, about 7% heavier than the left and contains about 7% more RNA and DNA. The two kidneys have almost identical RNA and protein contents per cell. 3. There is a very good correlation between the weights of the right and left kidneys of normal rats. There is also a good correlation between right kidney weight and body weight. The correlation between total renal weight and body weight is slightly better then either that between right kidney weight and body weight or that between total renal weight and liver weight. 4. There is good correlation between the total contents of DNA, RNA and protein of the right kidney and the body weight of the animal. There is no correlation between the DNA concentration, RNA content per cell and protein content per cell on the one hand and body weight on the other. 5. After unilateral nephrectomy the surviving kidney increases steadily in wet and dry weight, in rate and in mice, for the first 4 days after the operation. This is accompanied by a much slower increase in cell number by a small increase in protein content per cell end by a dramatic increase in RNA content per cell, These changes are accompenied by an increase in the activity of deoxy- ribonuclease I and II. There is no consistent change in the activity of DNA deoxynucleotidyltransferase activity after unilateral nephrectomy end no detectable change in serum sodium, potassium or chloride or in blood haematocrit. 6. Changes in kidney weight and in total contents of DNA, RNA, protein and lipid phosphorus can also be produced by varying the protein content of the diet. These effects were found to be of approximately the same magnitude as the effects of unilateral nephrectomy on the remaining kidney 4 days post-operatively. More over the two effects seem to be independent of each other end approximately additive. 7. Starvation does not significantly affect the mean cell mass or content of RNA per cell of the surviving kidney in the first 36 hours after unilateral nephrectomy, but it does apparently abolish the increase in protein content per cell. 8. The feeding of a diet containing 10% of urea by weight for 4 days increases the mean cell mass, RNA content per cell and protein content per cell of the kidneys of normal intact rats. Although these changes are similar to the effects produced in the remaining kidney after unilateral nephrectomy, they are only about one third as great, 9. The feeding of a diet containing 3% by weight of ammonium chloride for 6 days increases kidney weight by 25%, mean cell mass by 18%, RNA per cell by 19% and protein per cell by 18%. Equivalent amounts of ammonium citrate or sodium chloride do not produce these effects. The action of ammonium chloride would seem to be related to its acidotic effect rather than to the contribution it makes to either nitrogen excretion or electrolyte balance. 10. Decapsulation of the left kidney at the time of right unilateral nephrectomy does not affect the changes in weight or composition of the remaining kidney. 11. No consistent results could be obtained on RNA biosynthesis in the remaining kidney after unilateral nephrectomy using [3H] adenine as a precursor. The incorporation of [3H] erotic acid into the DNA of the surviving kidney was from 100 to 300 fold greater then the incorporation of [3H] adenine 4 hours pest-operatively. Unilateral nephrectomy did not produce any qualitative changes in the pattern of incorporation of [3H] orotic acid into kidney RNA as demonstrated by the sucrose density gradient technique. Quentitatively, however, the ratio of the specific activity of kidney RNA to that of liver RNA was 25% to 120% greater in unilaterally nephrectomized than in control animals at all times studied. 12. The RNA content per cell of the liver is increased substantially 2 days after removal of a 10% biopsy but is not affected by unilateral nephrectomy.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Additional Information: Adviser: G Russell
• Keywords: Biochemistry
• Date of Award: 1966
• Depositing User: Enlighten Team
• Unique ID: glathesis:1966-72255
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 24 May 2019 15:12
• Last Modified: 24 May 2019 15:12
• URI: https://theses.gla.ac.uk/id/eprint/72255