Medial Sclerosis Research Articles

Pathophysiology of aortic baroreceptors in rabbits with vitamin D sclerosis and hypertension.

Calciferol (vitamin D 2 ) (50,000-100,000 IU) and calcium lactate (1 g) were added to the normal diet of 22 rabbits for 7-11 days. When mean arterial blood pressure had risen from a control value of 87.2 ± 3.7 mm Hg to an experimental value of 137.8 ± 5.7 mm Hg (11-145 weeks), the aortic arch of 9 of these rabbits was isolated and perfused with Krebs-Henseleit solution. The impulse activity in 75 aortic baroreceptor fibers from the left aortic nerve was studied during nonpulsatile perfusion at different pressures and was compared with the impulse activity in 29 fibers from 17 normal rabbits. The threshold pressures and the pressure at the point of inflection of the curves were lower in these fibers than they were with fibers from normal rabbits. The gradient of the curves relating baroreceptor impulse frequency to aortic pressure was depressed from a normal mean value of 1.19 impulses/sec mm Hg -1 to 0.61 impulses/sec mm Hg -1 ( P < 0.001). A similar depression of the gradient was found in 7 baroreceptor fibers from the right aortic nerve. The change in the sensitivity of the baroreceptors was more closely related to the time interval after the calciferol treatment ( r =-0.95) than it was to the mean arterial blood pressure ( r = -0.76). The pressure-volume curves show that it was also related to the decreased distensibility of the aortic arch region. Histologically, the aortic arch region had extensive medial sclerosis with calcification.

Arterial repair and atherosclerosis after mechanical injury: Part 5. Tissue response after induction of a large superficial transverse injury

Sequential changes are described following production of a large area of superficial injury to the internal surface of the aortic wall of the rabbit. Early changes were acute inflammation, intimal thickening and partial reendothelialization of the injured segment. In rapidly reendothelialized regions the subendothelial thickening subsequently disappeared and the gross structure of the injured media was restored. The regions that were not rapidly reendothelialized were characterized by the formation of mural thrombi on the denuded areas, topical desquamation of the regenerating endothelium, increasing thickening of the intima, and accumulation of lipids as fine particles in the tissue. The results indicate that delayed reendothelialization promoted by recurrent formation of mural thrombi and desquamation of the regenerating endothelium are basic factors for the development of hyperplastic, lipid-containing lesions in this model system. By analogy, it is tentatively suggested that these same factors may also be of prime importance in the development of early atherosclerosis in man. Injured completely reendothelialized segments occurred at varying times after injury. Late reendothelialization was accompanied by tissue injury varying from the presence of scattered injured smooth muscle cells to gross necrosis of the underlying intima and media with the appearance of smooth muscle foam cells, monocyte-like foam cells, and cholesterol-containing foreign body giant cells. Subsequent changes in the necrotic regions included calcification, encapsulation, capillarization and dilatation. These results indicate that a sustained period with defective endothelium may induce changes in the arterial segment incompatible with the presence of a complete endothelial cover and that late reendothelialization may elicit gross tissue injury. It is suggested that a similar mechanism can be responsible for the transformation of early human atherosclerotic lesions to advanced lesions, for the development of complications in atherosclerotic lesions and for the formation of medial sclerosis.

Changes in the coronary vasculature in endomyocardial fibrosis and their possible significance

A series of changes affecting the coronary arteries was found during a postmortem histopathological study of 12 consecutive cases of endomyocardial fibrosis in Brazil. These changes seem to represent a spectrum, which includes medial degeneration, medial sclerosis, organizing fibrin deposition on the intimal surface, and the formation of plexiform lesions. Medium-sized and small arteries and arterioles within the fibrotic endomyocardial areas were mainly affected, but changes were also seen in other areas of the myocardium and in the epicardium. Lesions were not found in the vasculature outside the heart. The lesions in the coronary vasculature resemble morphologically the basic process of fibrosis that affects the endocardium and adjacent myocardium; they are, moreover, an important feature of the histopathological picuture of the disease, and may play a role in the pathogenesis of the accompanying myocardial damage.

Widespread spontaneous aortic lesions in the common brown hare ( Lepus europaeus)

Lesions seen in the thoracic aorta of the free-living hare ( Lepus europaeus) were similar to those previously described for the rabbit. They were not of the “spontaneous” atherosclerotic variety but resembled those of Mönckeberg's medial sclerosis.

Ultrastructural studies of the medial aortic sclerosis in rats with experimentally induced chronic renal disease

Ultrastructure of rat aortic medial sclerosis developing after experimental production of chronic renal disease is described. The calcium deposit in the medial layer of the aortic wall occurs with a predilection for the elastic fibers and more precisely the microfibrils of the elastic fibers. The calcification occurs in variable ultrastructural configurations. It appears that microfibrils and collagen fibers can act as a core of calcification. Ultrastructural modifications of smooth muscle cells such as increased cytoplasmic organelles, cytoplasmic cysternae, or vacuoles, and extension of many cytoplasmic processes are present without any atheromatous change of the wall.

Spontaneous Aortic Lesions in Rabbits I. Morphologic Characteristics

A number of morphologically distinct, spontaneously occurring lesions are present in the rabbit aorta. Intimal atheromata occur in newborn rabbits, decrease in incidence as the rabbit becomes weaned, and are a rarity in the adult. Intimal mesenchymal thickening is first seen in weanling rabbits and is almost universally present in the adult. Medial sclerotic changes involving exclusively the inner one-half of the media and termed "type A" lesions are present in weanling and adult, but not in newborn rabbits. Type A lesions have a variable gross appearance, but a fairly uniform microscopic appearance, which shows principally fragmentation and calcification of elastic lamina and accumulation of acid mucopolysaccharides. "Type B" lesions, medial sclerosis involving exclusively the outer half of the media, usually occur throughout the entire aorta, and only in adult rabbits.

Spontaneous Aortic Lesions in Rabbits II. Relationship to Experimental Atherosclerosis

Lesions in the rabbit aorta that occur spontaneously and contain no lipid consist of intimal mesenchymal proliferation and of medial sclerosis. Although the relationship of diet-induced atheroma to the intimal mesenchymal alterations is still not clear, our experiments have established that (a) the morphologic characteristics of diet-induced atheroma and of the spontaneous medial lesions are dissimilar at all stages of their development, and (b) the presence of spontaneous medial lesions clearly influences the development of atheroma. This influence is related to (a) an increased tendency for atheroma formation at the raised proximal and lateral borders of nodular medial lesions projecting from the luminal surface, (b) the absence of atheroma formation at sites of medial calcification, and (c) a propensity for lipid deposition in areas of acid mucopolysaccharide accumulation within spontaneous medial lesions.

Short-term aortic lipoidosis in the rat: Evaluation of some factors related to the experimental procedure

Summary In an endeavour to obtain, in a 4-week experiment, a maximum degree of macroscopically visible aortic lipoidosis in the rat, various modifications of an existing experimental procedure were tested. This experimental procedure consisted in feeding the rats with a semi-synthetic diet containing supplements of cholesterol, peanut oil, cholic acid, thiouracil, and a high or low level of protein (basic diet). Additional treatment with lactose, sucrose, NaCl, neomycin, and Triton, as well as withdrawal of choline or interrupted administration of the basic diet for a limited period of time, failed to increase significantly the degree of lipoidosis in the aorta. A significant decrease in aortic lipoidosis was found after the animals had been fed with a basic diet containing no chloride but rich in protein. A clear-cut increase in the degree of lipoidosis was obtained by combining the lipoidosis-producing diet with measures designed to cause medial sclerosis.

Intra-uterine myocardial infarction.

MYOCARDIAL infarction in the newborn is a rare event. Ravich and Rosenblatt reported 2 cases in 1947. 1 Subsequent reports have related such neonatal infarcts to an aberrant origin or other abnormalities of the coronary arteries such as medial calcific sclerosis, focal intimal proliferation, or subintimal fibrosis. 2-6 Most of these coronary lesions presumably develop during fetal life, and yet only one report has appeared of myocardial infarction in utero. 2 The current report records a second case of myocardial infarction in utero. The coronary arterial lesion proved of particular interest because of its similarity to lesions sometimes seen in adult coronary arterial disease. Report of a Case A 24-year-old, RH negative, gravida 2, para 1, white female was delivered of a 7 lb., 10 oz. (3,458.6 gm.) female following a pregnancy complicated only by a 36-lb. (18 kg.) weight gain. Labor was oxytocin (Pitocin) induced and lasted 4½ hours.

Revascularization of the heart; histologic changes after arterialization of the coronary sinus.

A free graft of vein was placed between the aorta and coronary sinus. Three weeks later the sinus was partially occluded at its ostium in the right auricle. Blood from the aorta was made available to the myocardium by way of the venous system. After these procedures were done a histologic study of the venous and arterial channels was carried out. The coronary sinus and its tributaries showed hyperplasia of the intima. The anterior cardiac veins showed dilatation with little or no hyperplasia of intima. None of the veins became occluded. Complete occlusion of major coronary arteries was done. These arteries distal to the occlusion showed medial sclerosis and atrophy. They did not show thrombosis. The myocardium distal to an occluded artery showed many vascular channels.

Cholesterol metabolism and arteriosclerosis

Cholesterol metabolism and arteriosclerosis

Congenital medial sclerosis of the coronary artery

Congenital medial sclerosis of the coronary artery

The Pituitary Factor in Arteriosclerosis Its Experimental Production in Rabbits

Article1 December 1930The Pituitary Factor in Arteriosclerosis Its Experimental Production in RabbitsROBERT C. MOEHLIG, M.D., EUGENE A. OSIUS, M.D.ROBERT C. MOEHLIG, M.D.Search for more papers by this author, EUGENE A. OSIUS, M.D.Search for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/0003-4819-4-6-578 SectionsAboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail ExcerptExperimental production of arteriosclerosis in rabbits has been accomplished by several workers. Anitschkow and Chalatow1, Bailey2 and others, have used various sorts of diets high in fats or fat-like substances to produce these changes.Certain facts led us to approach the problem from a new angle. The relationship between the pituitary gland and fat and carbohydrate metabolism suggested that the pituitary secretion might be concerned in arteriosclerosis.While the exact pathogenesis of arteriosclerosis is somewhat in doubt, nevertheless the cholesterol infiltration of the blood vessels is definitely established.The importance of the suprarenal cortex in cholesterol metabolism is well recognized....References ANITSCHKOWCHALATOW NS: Uber experimentelle Cholesterinsteatose und ihre Bedeutung für die Entstehung einiger. pathologischer Prozesse. Centralbl. f. allg. Path. u. Anat. 24:1, 1913. Google Scholar BAILEY CH: Atheroma and Oother Lesions Produced in Rabbits by Cholesterol Feeding. J. Exper. Med. 23:69, 1916. CrossrefMedlineGoogle Scholar GOLDZIEHER M: The Adrenals. The Macmillan Co., New York, 1929, p. 250-251. Google Scholar MOEHLIG RC: A Study of the Ductless Glands: Detroit Med. J. 14:268, 1914; Ductless Gland Cell Control, Monograph, 1918, p. 87; Selective Tissue Action of Posterior Pituitary Gland: Med. Jour. and Rec. 120, (August 20) 55, 1924. Selective Action of the Suprarenal Cortex on Mesothelial Tissues: Am. J. M. Sc. 168, 553, 1924. Embryohormonic Relations of the Pituitary Gland to Mesenchymal Tissues; Ann. Int. Med. 1:563, 1928. Embryohormonic Relations of the Suprarenal Cortex to Mesothelial Tissues: Ann. Int. Med. 1:828, 1928; Pituitary Gland and Suprarenal Cortex, Arch. Int. Med. 44:339, 1929. Google Scholar MOEHLIGAINSLEE RCH: Posterior Pituitary Extract and Cholesterol Metabolism, Am. J. Physiol. 80:649, 1927. Pituitary Gland and Cholesterol Metabolism: Ann. Clin. Med. 5:772, 1927. CrossrefGoogle Scholar KROGH A: The Capillaries. Yale Press, 1922. Google Scholar SHAPIRO S: The Relation of Certain Glands of Internal Secretion to the Development of Atherosclerosis. Endocrinology, 11:279, 1927. CrossrefGoogle Scholar SACKETT GE: Modification of Bloor's Method for Determination of Cholesterol in Whole Blood or Blood serum. Jour. Biol. Chem. 64:203, 1925. CrossrefGoogle Scholar ISCOVESCO H: Sur les propriétés d'un lipoïde Extrait de la partie corticale des capsules surrénales, Compt. rend. Soc. Biol. 75:510, 1913. Google Scholar This content is PDF only. To continue reading please click on the PDF icon. Author, Article, and Disclosure InformationAffiliations: Detroit, Michigan*This work was carried out with the assistance of the technical staff of Harper Hospital laboratory. PreviousarticleNextarticle Advertisement FiguresReferencesRelatedDetails Metrics Cited byArteriosklerose und Innere SekretionDie Krankheiten des HypophysenzwischenhirnsystemsDie Bedeutung der Hypophyse für die Pathologie der BlutgefäßeCongenital medial sclerosis of the coronary artery 1 December 1930Volume 4, Issue 6Page: 578-592KeywordsBlood vesselsCarbohydrate metabolismCholesterolDietFatsPathogenesisPituitary glandRabbitsResearch laboratories ePublished: 1 December 2008 Issue Published: 1 December 1930 PDF downloadLoading ...