The Effect of Adrenocorticotropin on the Nucleic Acids and Histochemistry of the Guinea-Pig Adrenal Cortex

Burns, Joseph Kieran (1957) The Effect of Adrenocorticotropin on the Nucleic Acids and Histochemistry of the Guinea-Pig Adrenal Cortex. PhD thesis, University of Glasgow.

Abstract

The effect of adrenocorticotropin (Armour ACTHar gel) on the mean amount of deoxyribonucleic acid (DNA) per nucleus, and the scatter about this mean, in adrenal nuclei from mature guinea-pigs was studied, using cytophotometry of Feulgen stained nuclear smears. The results were compared with those from chemical analysis of the same material. The mean adrenal nuclear DM content was similar to that in a control specimen mounted on the same slide in each instance, except after administration of adrenocorticotropin for 5 and 7 days. Cytophotometric analyses showed a highly statistically significant increase (P<0.01) in mean adrenal nuclear DNA content after treatment of the animals with ACTH for 5 and 7 days, Chemical analyses gave values for adrenal nuclear DNA which were slightly higher than those for pooled kidney nuclei. The significance of these findings is discussed. Statistical analysis of the results indicates that only specimens on the same slide are to be compared when using cyto-photometry of the Feulgen reaction. If specimens on different slides are used for comparison a large error is introduced. The effect of ACTH was also studied on adrenocortical ribonucleic acid (RNA), plasmalogens, alkaline and acid phosphatase, ascorbic acid and glycogen in mature guinea-pigs after treatment with ACTH for similar periods of time (1, 3, 5, 7, 10, 14 and 21 days) and also for 3, 6, 12 and 18hr and for 28 days. A gradual increase in adrenocortical ribonucleic acid occurred with ACTH treatment. This increase was found in all zones of the adrenal cortex. Depletion of lipid and of plasmalogens was evident in the zona fasciculata and zona reticularis after ACTH administration for 3, 6, 12 and 18 hr. In the other experimental groups of animals an increase in lipid and plasmalogens occurred with continued ACTH administration. At 28 days, however, some depletion of these substances was found in the zona reticularis. ACTH administration caused an increased concentration of alkaline and acid phosphatase in all adrenocortical zones. The increase was most evident after treatment with ACTH for 5 and 7 days, when hyperplasia was maximal. Ascorbic acid depletion was observed after ACTH treatment for 3, 6, 12 and 18 hr and for 1 day. The adrenocortical content and distribution of ascorbic acid was normal in adrenals of guinea-pigs receiving ACTH for longer periods. Glycogen depletion occurred at 12 and 18 hr only. The findings are discussed and compared with results of other authors who studied the pituitary-adrenal relationship. It is evident that ribonucleic acid, alkaline and acid phosphatase and ascorbic acid have important roles in adrenocortical Physiology. The results suggest that ribonucleic acid and phosphatases are probably concerned with adrenocortical hyperplasia. It seems more likely, however, that ascorbic acid and glycogen are concerned with secretion of adrenocortical hormones, as depletion of these substances occurred when secretion of ketosteroids was probably at a maximum.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Neurosciences, Histology, Biochemistry
• Date of Award: 1957
• Depositing User: Enlighten Team
• Unique ID: glathesis:1957-79235
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 31 Mar 2020 09:09
• Last Modified: 31 Mar 2020 09:09
• URI: https://theses.gla.ac.uk/id/eprint/79235