Abstract
Previous findings have shown a turnover of nuclear DNA, a condition related to the functional activity of these cells, in the adrenal medullae of rats intermittently exposed to cold. Striking differences have been observed between various strains of rats, particularly Italico and Wistar rats.
In order to evaluate the function of the adrenal medullary cells, the content of catecholamines in the organ and their urinary excretion have been evaluated, with the fluorimetric method, in rats of Italico and Wistar strains kept at room temperature and exposed intermittently to cold. The results show that (i) at room temperature the levels of excretion are lower in Italico than in Wistar rats in spite of the equal amine contents of the adrenal medullae, (ii) the first exposure to cold causes a large increase in the urinary excretion and a decrease of adrenaline and noradrenaline content of the adrenal glands in both strains, (iii) after 3 days the catecholamine content in the organ was higher than normal in Wistar rats, whereas in the Italico strain it continued to decrease, and (iv) a new steady state at higher levels is reached after 20 days of exposure, when not only the catecholamine content but also the urinary excretion is equal in both strains.
These differences between the two strains of rats during intermittent cold exposure are discussed in relation to the behaviour of DNA.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- ANTON A. H., SAYRE D. F. A study of the factors affecting the aluminum oxide-trihydroxyindole procedure for the analysis of catecholamines. J Pharmacol Exp Ther. 1962 Dec;138:360–375. [PubMed] [Google Scholar]
- CASS R., CALLINGHAM B. A. SOME EFFECTS OF DRUGS WHICH INFLUENCE SYMPATHETIC TRANSMISSION ON TISSUE CATECHOLAMINE LEVELS IN THE RAT. Biochem Pharmacol. 1964 Dec;13:1619–1625. doi: 10.1016/0006-2952(64)90216-3. [DOI] [PubMed] [Google Scholar]
- COUPLAND R. E. Strain sensitivity of albino rats to reserpine. Nature. 1958 Mar 29;181(4613):930–931. doi: 10.1038/181930a0. [DOI] [PubMed] [Google Scholar]
- Cession-Fossion M. A., Henrotte J. G., Duchesne P. Y., Beaumariage M. L. Teneur en catécholamines des surrénales et de l'hypothalamus de rats élevés en ambiance chaude. C R Seances Soc Biol Fil. 1966;160(11):2218–2220. [PubMed] [Google Scholar]
- DesMARAIS A., DUGAL L. P. Circulation périphérique et teneur des surrénales en adrénaline et en artérénol (noradrénaline) chez le rat blanc exposé au froid. Can J Med Sci. 1951 Jun;29(3):90–99. [PubMed] [Google Scholar]
- LEDUC J. Catecholamine production and release in exposure and acclimation to cold. Acta Physiol Scand Suppl. 1961;183:1–101. [PubMed] [Google Scholar]
- MOORE K. E., CALVERT D. N., BRODY T. M. Tissue catecholamine content of cold-acclimated rats. Proc Soc Exp Biol Med. 1961 Apr;106:816–818. doi: 10.3181/00379727-106-26485. [DOI] [PubMed] [Google Scholar]
- Tongiani R., Viola-Magni M. P. II. Differences in adrenal medulla nuclear DNA content among rats of different strains following intermittent exposure to cold. J Cell Biol. 1969 Aug;42(2):452–459. doi: 10.1083/jcb.42.2.452. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Viola-Magni M. P. A radioautographic study with H3-thymidine on adrenal medulla nuclei of rats intermittently exposed to cold. J Cell Biol. 1966 Jan;28(1):9–19. doi: 10.1083/jcb.28.1.9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Viola-Magni M. P. Changes in the DNA content of adrenal medulla nuclei of rats intermittently exposed to cold. J Cell Biol. 1965 Jun;25(3):415–433. doi: 10.1083/jcb.25.3.415. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wurtman R. J. Control of epinephrine synthesis in the adrenal medulla by the adrenal cortex: hormonal specificity and dose-response characteristics. Endocrinology. 1966 Sep;79(3):608–614. doi: 10.1210/endo-79-3-608. [DOI] [PubMed] [Google Scholar]
- Wurtman R. J., Noble E. P., Axelrod J. Inhibition of enzymatic synthesis of epinephrine by low doses of glucocorticoids. Endocrinology. 1967 May;80(5):825–828. doi: 10.1210/endo-80-5-825. [DOI] [PubMed] [Google Scholar]