FACTORS ALTERING CONCENTRATION OF BLOOD LIPIDS 469 



to produce atherosclerosis in cats or dogs by cholesterol feeding, Steiner 

 et al. uo obtained positive results when thiouracil was also given. These 

 results would indicate that atherogenesis may occur more readily when 

 hypofunction of the thyroid gland obtains. This is in line with the report 

 of Katz and co-workers 741 that the thyroid hormone is able to suppress 

 both hypercholesterolemia and atherogenesis. This is accomplished by a 

 direct effect on lipid metabolism, since it does not follow the administration 

 of the thyroid-stimulating hormone of the anterior pituitary gland. 



Hormones other than those associated with the thyroid are also active in 

 relation to atherogenesis. Thus Compound F (17-hydroxycorticosterone) 

 markedly intensifies hypercholesterolemia and hyperlipemia in cholesterol- 

 fed chicks, without influencing blood pressure or atherogenesis. 741 ACTH 

 in large doses duplicates these effects, in contrast to the opposite behavior 

 of cortisone and desoxycorticosterone. The estrogenic hormones, when 

 given with a high cholesterol diet, completely prevent the development 

 of atherosclerosis. In chicks with developed atherosclerosis resulting from 

 cholesterol ingestion, the coronary lesions were completely reversed, 

 when estrogens were given, despite the continued feeding of atherogenic 

 material. These effects could be maintained when androgenic hormones 

 were given simultaneously. The estrogen effect was shown to be associated 

 with significant alterations of the plasma lipid-lipoprotein patterns. It 

 was found that the total cholesterol : lipid P ratio was reduced toward 

 normal levels. 741 



Vitamin B 6 has also been considered to be associated Math the develop- 

 ment of atherosclerosis. Thus, in the case of the monkey, Rinehart and 

 Greenberg 742,743 succeeded in producing an atherosclerosis by means of a 

 pyridoxine-deficient diet, while prolonged feeding with cholesterol failed 

 to produce significant lesions. In a later study, 744 it was shown that a 

 greater degree of cholesterolemia was present in the pyridoxine-deficient 

 monkey receiving cholesterol than in the normal animal which received 

 considerably higher quantities of cholesterol. Mice and rats are resistant 

 to atherosclerosis, as are also hamsters. 745 " -747 Although Altschul 746 was 



740 A. Steiner, F. E. Kendall, and M.-Bevans, Am. Heart J., 38, 34^2 (1949). 



741 L. N. Katz, R. Pick, and J. Stamler, XlXth Intern. Physiol. Congress, Montreal 

 (Aug.-Sept., 1953), Abst., 505-506. 



742 J. F. Rinehart and L. D. Greenberg, Am. J. Pathol, 25, 481-491 (1949). 



743 J. F. Rinehart and L. D. Greenberg, Arch. Pathol, 51, 12-18 (1951). 



744 L. D. Greenberg and J. F. Rinehart, Proc. Soc. Exptl. Biol Med., 76, 580-583 

 (1951). 



745 J. Goldman, Arch. Pathol, 49, 169-172 (1950). 



746 R. Altschul, Am. Heart J., 40, 401-409 (1950). 



747 W. Marx, L. Marx, and H. J. Deuel, Jr., Am. Heart J., 42, 124-128 (1951). 



