Gardevski, M.

Kemileva, Z.

Uzunova, A.

English

Varna Medical University Press: Journals

THE INFLUENCE OF THYMUS ON EXPERIMENTAL MYOCARDITIS AND ARTHRITIS (MORPHOLOGICAL STUDY)M. Gardevski, Z. Kemileva, A. UzunovaThe intensive experimental studies on the thymus, performed in recent years, have shown its outstanding role in the formation of immune res-ponse in the organism {Miller, 1961, 1963, 1965; Aisenberg and assoc., 1964; Pinnes and assoc., 1966; Metcalf and assoc., 1967). It has been established that neonatal thymectomy in mammalians results in reduction of the num-ber of lymphocytes in the peripheral blood and lymph circulation, lymphoid hypoplasia, lowered antibody production and inhibition of hypersensi-bility reactions of a delayed (cellular) type (Atnason and assoc. — 1962, Ю64; Waksman and assoc., 1962; Jankovic and assoc., 1962; Lujan and Can- diolo, 1965). Lately, rheumatism also was ranked among the latter type of reactions {Bibikova and assoc., 1965; Borisova and assoc., 1966; Borisova, 1967).The aim of the present work is to investigate the influence exerted by neonatal thymectomy on the morphological changes in myocarditis and arthritis in rats, assumed as an experimental model of rheumatism in hu-mans.Material and MethodThe experiments were performed on a series of 59 rats of both sexes, divided in two groups: control group, comprising 28 animals, and experi-mental — 31 animals. The rats of the latter group were subjected to thy-mectomy through aspiration within 48 hours of birth. The number of ani-mals of the experimental group does not include those in which, following autopsy, residual thymus or septic processes were established at the site of operative intervention. Experimental myocarditis and arthritis were induc-ed in all the animals after the third month of life, according to a method, elaborated at the Chair of Pathophysiology — Higher Medical Institute, Varna. Twenty-four-hour culture of Beta-streptococcus heamolyticus, group A, was administered three times via i. v. injection, at dose 0,2 ml of 1000 million suspension, at 15-day intervals. Material for histological investi-gation was taken after killing the animals, two weeks after the last intro-duction of culture. The paraarticular connective tissue and myocardium of all the animals was subjected to histological investigation. The material for histological investigation was fixed in 10% neutral formalin and treat-ed according to the paraffin method. The histological preparations were stained with hematoxylin eosin, and with toluidine blue for demonstra-tion of the collagen destruction, at different pH of the solutions.3 Scripts sclentlfka medlca34 M. Gardevski, Z. Kemileva, A. Uzunova 2Results and DiscussionInflammatory changes in the paraarticular connective tissue and mu-coid turgescence of the connective tissue was established in 21 control ani-mals (75%) and in 13 of the group of thymectomized — 42 per cent (Fig. 1). The inflammatory reaction of the paraarticular tissue revealed a product-ive-proliferative character and was manifested by infiltrates of lympho-cytes, histiocytes and mastocytes, ag-glomerated around the blood vessels in a cuff-like fashion. The walls of the blood vessels in these particular zones appear thickened, homogeneous, with pale-pink coloration (фиг. 2). The connective tissue fibres are swol-len, with slight basophilic tinge and deleted structural outlines. The chan-ges in the paraarticular connective tissue of the thymectomized animals do not differ in nature from those in the controls, except that they are comparatively less defined.The changes in the myocardium display the same regularity, namely, affection of a greater number of ani-mals of the control group. Well mani-fested inflammatory changes and dis-organization of the connective tissue were established in 24 out of a total of 28 rats in the control group (85,7%). Among the thymectomized animals, inflammatory changes were discovered in 15 out of a total of 31 animals in the group (48,4%) (Fig. 1). The changes in the myocardium were ma-nifested by focal perivascular ammassments of oval cells (lymphocytes, histiocytes, monocytes and mastocytes), displaying resemblance to rheuma-tic granulomas and absence of typical Aschoff’s cells. In some animals, diffuse round-cellular infiltration was present within the interstitial tissue of the myocardium (Fig. 3). The connective tissue, surrounding the blood vessels of the myocardium was characterized by mucoid turgescence.The cellular infiltrates and the signs of mucoid turgescence observed afford the possibility for making analogy between the pathological pro-cess described and the first stage of rheumatic reaction in humans. The latter concept is corroborated by the fact that nowadays, the Aschoff— Talalaev granuloma is not considered a mandatory sign in the diagnosis of rheumatism (Mitin, 1966).The presence of a greater number of infiltrates in the control animals may be due to the preserved inmmunologic reactivity, related to the fun-ction of the thymus. The studies of Kosunen and coworkers (1963) on the mechanism of cellular hypersensitivity, by way of autoradiography, show that the cellular infiltration is caused by migrating lymphocytes, which subsequently become transformed into histiocytic elements and stimulate□  Control animals Q  Thymectomized. animalsFig. 1. Percentage of inflammatory chang-es e-tablished in the paraarticular con-nective tissue and myocardium.3 The influence of thymus on experimental 35Fig 2. Paraarticular connective tissue -  mucoid tureescence and proliferation of ovoid cells surrounding a blood vessel.'^tain H Emagnif. 10X20 ' ’’Fig. 3. Myocardium — focal perivascular ammassment of cells resembling rheumatic granulomas.36 M- Gardevski, Z. Kemileva, A. Uzunovathe local proliferation of cells. The neonatal thymectomy which pro-vides for lymphocytic hypoplasia (Aisenberg and others, 1964, Metcalf and co-workers, 1967) obviates the development of similar infiltrates, or else they are less defined in the animals of the experimental group.The character of the histologic-al changes and the substantial dif-ferences in the results of the two groups justifies the classification of the pathologic process, induced by the triple intravenous injection of Beta-streptococcus haemolyticus in rats, as an alergic reaction.The histochemical investigation with toludine blue at different pH of the solutions (2,62, 3,62, 4,62, and 5,32), discloses a permanent metachromatic scale in the para-articular tissue and myocardium. It is more pronounced in the myocardium and is found main-ly in the parietal endocardium, in the fibrous ring of the val-vular openings, in the walls of the major vessels and in the pe-rivascular connective tissue. The metachromasia in the control group of animals is more evident, ocurs in a greater number of ani-mals and has a diffuse character (Figs. 4, 5). In the thymectomiz- ed animals, only focal meta-chromasia was established and that in a much smaller number of animals.Metachoromasia with toluidi- ne blue at pH beneath 4 is ac-cepted {Pire, 1961, Mi tin, 1966) as indicative mainly of accumu-lation of sulfatized acid muco-polysaccharides in the tissues and is an expression of a slighter degree of connective tissue des-truction. The metachromasia at pH exceeding 4 is considered due to the accumulation of hyaluronic acid and demonstrates a heavier damage of the connective tissue. The strongly pronounced, diffuse metachromasia with toluidine blue in the paraarticular tissue and myocardium of the con-o— o C ontrol a n im a ls  o------ o ThymectorriiLed a n im a lsFig. 4. Number of animals with proved me-tachromasia with toluidine blue in the para-articular connective tissue at varying pH of solutions.3 0 -§22-18 —14-10-6 -2 -0 i rZ 2,613 3.62 4.62 S,32o— o Control anim als «------o Thymectomized anim alsFig. 5. Number of animals with toluidine blue proved metachromasia in the myocardium at various pH of solutions.-i—r5 The influence of thymus on experimental. . . 37trol animals, at varying acidity of solutions, is indicative of the presence equally of sulfatized acid mucopolysaccharides and also of hyaluronic acid. This is an indication that in this group of animals, the varying degrees of lesion are more strongly pronounced as compared to experi-mental animals.Inference1. The threefold intravenous injection of Beta-streptococcus haemoly- ticus, group A, provokes signs of tissue allergic reaction in the paraarticu-lar connective tissue and myocardium of rats. 2. Neonatal thymectomy inhi-bits the tissue allergic reaction in the paraarticular tissue and myocardium of the animals.R E F E R E N C E S1. Б н б и к о в а ,  Г. A. ,  A.  M. Б о р и с о в а ,  C . C. М у т и н ,  Я. А. С и -т и д и н. Опнт дальнейшего изучения аллергин замедленного типа при рев- матизме. Современние проблеми ревматологии АМН  СССР, М., 1965, 56—60.2. Б о р и с о в а, А. М., Я. А. С и г и д и н .  Об алергии у сердечнон тканипри ревматизме. Вопр. ревматизма, 1, 13— 17, 1966.3. Б о р и с о в а, А. М. Некоторне итоги изучения аллергии земедленого типапри ревматизме. Вопр. ревматизма, 3, 61—66, 1967.4. М и т и н ,  К. С. Гистохимия соединительной ткани сосудов при ревматизме,«Медицииа>, М., 1966.5. П и р с. Гистохимия, 1962, 224—231.6. A i s е п b е r g, А. С., В. W i l k e s .  Immunologic status of thymectomizedadult rats. J. 1 mmunology, 1964, 93, 75—80.7. A r n a s o n ,  B.  G. ,  B.  D.  J a n k o v i c ,  W a k s m a n ,  W e n n e r s t e n .Role of the thymus in immune reactions in rats. J . exp. Med., 1962, 116, 177-178.8. A r n a s o n, B. G., B. D. J a n k o v i c, В. H. W a k s m a n. The role of thethymus in immune reactions in rats. In the thymus in Immunobiology. Ed. by R. A. Good and A. E. Gabrielsen, Hoeber—Harper, New York, 1964.9. J a n k o v i c ,  B.  D. ,  В.  H.  W a k s m a n ,  B.  G.  A r n a s o n .  Role of thethymus in immune reactions in rats. I. The immunologic response to bovine serum albumin in rats thimectomized or splenectomized at various times after birth. J. exp. Med., 1962, 116, 159— 176.10. K o s u n e n ,  T. U. ,  В.  H.  W a k s m a n ,  M.  H.  F l a k ,  W. S. T i h e n.Radioautographic study of cellular mehanisms in dilayed hypersensitivity. J. Im -munology, 1963, 6, 276.11. L u j a n, M. А., В. C a n d i o 1 o. Influence of thimectomy on experimentalpoliarthritis. Acta physiol. Latino Americana, 1965, 15, 32—37.12. M e t c a 1 f, D., M. B r u m b y .  The role of the thymus in the ontogeny of theimmune system. J . cell. Physiol, sup., 1967, 1, 149—168.13. M i l l e r ,  J.  F. A. P. Immunological function of the thymus. Lancet, II, 1961,748—749.14. M i l l e r ,  J.  F. A. P. Immunity and the thymus. Lancet, 1963, 1, 43—45.15. M i 1 1 e r, J. F. A. P. The role of the thymus in immune processes. In t. Arch.Allergy, 1965, 28, 61—70.16. P i n n a s, J. Z., F. W. F i t e  h. Immunologic competence of thymectomizedrats to several soluble and particulate antigens. In t. Arch. Allergy, 1966, 30, 217—230.17. W a k s m a n, В. H., B. G. A r n a s o n ,  B.  D.  J a n k o v i c .  Role of thethymus in immune reactions in rats III. Changes in the lymphoid organs of thyme-ctomized rats. J. exp. Med., 1962, 116, 187—206.38 M. Gardevski, Z. Kemileva, A. Uzunova 6ВЛИЯНИЕ ТИМУСА HA ЗКСПЕРИМЕНТАЛЬНЬ1Е МИОКАРДИТ И АРТРИТМ . Гирдевски, 3 . Кемилева, А . Узунова Р Е З Ю М ЕИсследованн гистологически и гистохимически околосуставиая соединительная ткань и миокард у 31 неонатально тимзктомированних и 28 контрольних крие, у ко- торих в 3-месячном возрасте били визванн зкепериментальние миокардит и артрит. Полученние инфильтрати продуктивно-пролиферативной природи и мукоидное про- пнтьшание напоминают Ашов—Талалаевсквй гранулем в начальной стадии ревма-тизма. Неонатальная тимзктомия подавляет развитие аллергичеекон воспалительной реакции клеточного типа в околосуставной ткани и миокарде. Зта реакция связи- вается с лимфоидной гипоплазией и со сниженной иммуниой реактивностью тимезкто- мированних жнвотних.

THE INFLUENCE OF THYMUS ON EXPERIMENTAL MYOCARDITIS AND ARTHRITIS (MORPHOLOGICAL STUDY)

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THE INFLUENCE OF THYMUS ON EXPERIMENTAL MYOCARDITIS AND ARTHRITIS (MORPHOLOGICAL STUDY)

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