1. General Pathology Basic Principles of Cellular and Organ Pathology Autogenous Pigments Jaroslava Dušková Inst. Pathol.,1st Med. Faculty, Charles Univ. Prague

2. Pigments Definition: colored substances in the organism or environment

3. Pigments Classification: u endogenous v autogenous v hemoproteins derived u exogenous

4. Autogenous Pigments - color substances formed in the organism as metabolism products  melanin  ceroid  lipofuscin

5. Melanin u oculocutaneous (origin from tyrosine in melanocytes) u neuromelanin - subst. nigra (origin from dopamin)

6. Melanin - types u eumelanin – insoluble, brown-black u phaeomelanin – soluble, yellow-red (high sulphur content)

7. Melanin - production Melanocytes –derived from the neural crest –present in the basal layer of epidermis, dermis, hair folicles, mucose membranes, uveal tract of the eye, meninges, inner ear –secretory in the contact with the epithelial cells - cytocrinia

8. Melanin Functions – 1. u cytoprotective –light absorption & conversion of the photon energy into heat –uvea – absorption of the light retina protection of light overexposure –retina - visual acuity preventing light reflexion from the fundus

9. Melanin Functions -2. u Ion exchanging capacity Melanosomes can also act as detoxyfiing and excretory components accumulating great number of drugs and toxic component e.g. heavy metals. Scavengers of the free radicals. Rarely cytotoxic – photosensibilisation

10. Melanin - Features u brown u destained with H 2 O 2 u reducing AgNO 3

11. Disorders of Melanin Pigmentation Lack u generalized –total albinism –parcial albinism u local –vitiligo –leucoderma

12. Albinism u autosomal recessive heredity – tyrosinase deficiency – tyrosinase positive – melanosomes defect u oculo-cutaneous albinoidism – dominant inheritance

13. Disorders of Melanin Pigmentation Lack u generalized –total albinism –parcial albinism u local –vitiligo –leucoderma

14. Vitiligo u familial aggregation u polygenic nature u association with other autoimmune diseases (DM, thyroiditis, gastritis) u ab against tyrosinase in the serum u autoreact. T- cellular cytotoxicity

15. Disorders of Melanin Pigmentation Lack u generalized –total albinism –parcial albinism u local –vitiligo –leucoderma

16. Leucoderma u postinflammatory circumscribed depigmentation e.g. – leucoderma syphyliticum – leucoderma psoriaticum

17. Disorders of Melanin Pigmentation Increase u generalized –Adison disease u local –freckles, nevi –chloasma /melasma –melanodermia –melanoma

18. Disorders of Melanin Pigmentation Increase u generalized –Adison disease u local –freckles, nevi –chloasma –melanodermia –melanoma

19. Disorders of Phenylalanine and Tyrosine Metabolism 1. Phenylalanine hydroxylase PHENYLKETONURIA 2. Homogentisic acid oxydase ALKAPTONURIA 3. Tyrosinase ALBINISM

20. Disorders of Phenylalanine and Tyrosine Metabolism Phenylalanine Tyrosine methyl– acetoacetic acid DOPA MELANIN Norepinephrine Epinephrine 3 1 2 Homogentisic acid cc

21. Ceroid u features – light brown – PAS + – acidoresistent – Sudan +- u origin – fagocytosis od lipid substances by macrophages – oxidation of non–saturated lipid acids

22. Ceroid u localisation – places of erythrocytes destruction – necroses of adipous tissue – avitamonosis E – melanosis coli – Dubin - Johnson syndrome

23. Lipochrom  ubiquitous pigment u exogenous origin u lipid solvent u histologically unprovable

24. Lipofuscin u features – dark brown – Sudan +- – autofluorescence

25. Lipofuscin u origin – autophagocytosis "wear and tear" pigment from the accumulation of autophagolysosomes over time.

26. Lipofuscin u localisation – CNS, epithels, muscles, liver ATROPHIA FUSCA