Buradasınız

Anasayfa » Content

SÜREKLİ KARANLIK VE IŞIĞA MARUZ KALAN SIÇANLARIN TİMUSUNDAKI HİSTOLOJİK DEĞİŞİKLİKLER

Histologic changes in thymus of the rats exposed continuous darkness and continous light

Journal Name:

  • İnönü Üniversitesi Tıp Fakültesi Dergisi

Publication Year:

  • 1998

Key Words:

Keywords (Original Language):

Author NameUniversity of AuthorFaculty of Author
Abstract (2. Language): 
It is known that periods of constant darkness and constant light cause stimulation and inhibition of melatonin secretion from the pineal gland. In this study, we provide experimental evidence that changes in the rhythm of the photoperiod have considerable effects on thymic structure of the rats. Male albino rats were divided into 3 groups. Group I rats were exposed to a 12:12 h light: dark cycle, group II rats were kept in a dark vicinity, group III in a vicinity under a bright artificial light. All animals were killed after 8 wk. In group II, thymus weight increased. Thymic cortical epithelial cells hypertrophied. In group III thymus weight decreased. Thymic cortical epithelial cells and lymphocytes had decreased, pyknotic lymhocyte nuclei were frequently in the cortex and medulla. It is concluded that constant darkness causes hypertrophy and increased cellularity of the thymus, while constant light causes involution of the thymus and death of lymphocytes. These changes possibly may be atributed the immunostimulatory effects of melatonin acting directly or indirectly, on the lymphocytes and epithelial cells.
Bookmark/Search this post with
Abstract (Original Language): 
Sürekli karanlık ve ışığın, epifiz bezinden melatonin salgılanmasını inhibe ve s/tümü/e ettiği bilinir. Bu çalışmada, sıçan timus yapısını bir hayli etkileyen fotoperiyod ritmindeki değişikliklere deneysel kanıt sağladık. Erkek albino sıçanlar üç gruba ayrıldı. I. Grup kontrol sıçanlar, 12:12 saat, ışık: karanlık sik/usuna; II. Grup sıçanlar, sürekli karanlık ortama; III. Gruptakiler ise parlak suni ışığa maruz bırakıldı. Tüm hayvanlar 8 halta sonra öldürüldü. II. Grupta timus ağırlığı artmıştı. Tim/k epitelyal hücreler hipertrofikti. III. Grupta ise timus ağırlığı azalmıştı. Timik kort/kal epitelyal hücre/er ve lenfositler azalmıştı, piknot/k çekirdek/i lenfosit/er sıklıkla korteks ve medulladaydı. Sürekli karanlık hipertrofiye ve hücresel artışa neden olurken, sürekli aydınlık timusun involüsyonuna, lenfositlerin ölümüne neden olmuştu. Timik lenfositler ve epitel hücrelerini, direkt veya indirekt olarak etkileyen bu durum melatoninin, immünositümülator etkisine atfedilebilir.
FULL TEXT (PDF): 
PDF icon arastirmax-surekli-karanlik-isiga-maruz-kalan-sicanlarin-timusundaki-histolojik-degisiklikler.pdf
  • 4
217-220
  • Turkish

REFERENCES

References: 

1. Plotnikoff NP, Faith BE, Murgo A], Good RA. Ying Yang hypothesis of immunomodulatJon. In Enkephalins and Endorphins: Stress and the Immune System (ed. N.P. Plotnikoff, B.E. Faith, AJ, Murdo and R.A. Good), pp. 1-2. New York: Plenu Press. 1986.
2. Brown GM, Niles LP. Studies on melatonin and other pineal factors. In Clinical Neuroendocrinology, (ed. G.M. Bessser and L. Martini). New York: Academic Press. 1982;vol.l:205-53.
3. Kinson GA, Peat F. The influences of illumination melatonin and pinealectomy on testicular function in the rat. Life Sciences 1971;10:259.
4. Shirama K, Furuya T, Takeo Y, Shımızu K, Maekawa K. Direct effect of melatonin on the accessory sexual organs in pinealectomized male rats kept in constant darkness. Journal of Endocrinology 1982;95:87-94,.
5. Erlich SS, Appuzo MU. The pineal gland: anatmy, physiology and clinical significance. Review Article. Journal of Neurosurgery. 1985;63:321-341.
6. Wurtma RI. Effect of light ad visual stimuli on endocrine function. In Neuroendocrinology, (ed. L. Martini and W.F. Ganong). New York: Academic Press. 1967;vol. 11:20-59.
7. Jankovic BD, Isakovic K, Petrovic S. Effect of pinealectomy on immune reactions in the rat. Immunology. 1970;18:1-16.
8. Fernandes G, Halberg F, Yunıs EJ, Good RA. Orcadian rhythmic plaque forming cell: respons of spleens from mice immunized with SRBC. Journal of Immunology. 1976;117: 962-6.
9. Maestroni GJM, Pierpaoli W. Pharmalogical control of the normally mediated immune response. In Psychoneuroimmunology (ed. R. Ader). New York: Academic Press. 1981;405-25.
10. Maestroni GJM, Cont A, Pierpaoli W. Role of the pineal gland in immunity:
II. Melatonin enhances the antibody response via an opiatergic mechanism. Clinical and Experimental Immunology 1987;68:384-91.
11. Maestroni GJM, Conti A,Pierpaoli W. Role of the pineal gland in immunity:
III. Melatonin antagonizes the immuno-suppressive effect of acute stress via an opiatergic mechanism. Immunology 1988;3:465-469.
12. Bloodworth JMB, Hıratsuka H, Hıckey RC. infrastructure of the human thymus, thymic tumors, and myasthenia gravis. Pathological Animals 1975;10:329-391.
13. Kalland T, Fossberg TM, Fossberg JG. Effect of estrogen and corticosterone on the lymphoid system in neonatal mice. Exp Molecular Pathol 1978;28:76-95.
14. Blask DE. The pineal: an oncostatic gland. In the pineal gland (ed. R.J. Reiter). New York: Raven Press. 1984;253-85.
15. Maestroni GJM, Conti A, Pierpaoli W. The pineal gland and the circadian, opiatergic, immunoregulatory role of melatonin. Annals of the New York Academy of Sciences 1987;496: 67-77.
16. Mahmoud I, Salman SS, AL-Khateeb. A continuous darkness and continuos light induce structural changes in the rat thymus. J Anat 1994; 85: 143-9.

Thank you for copying data from http://www.arastirmax.com