PIGMENTS - zona.fmed.uniba.sk · Endogenous pigments Autogenic pigments Melanin –corpuscular...

PIGMENTS

P. Babál

ÚPA LFUK

Pigments= substances having own color

- soluble

- corpuscular (granules, crystals...)

- responsible for pigmentation of tissues/organs

Endogenous Exogenous=produced in the organism =introduced from environment

1. Autogenous 1. Through skin/mucosa

(melanin, lipofuscin, lipochrom, (traumatic, tatoo..., bacterial

in ochronosis, ceroid) fungi...)

2. Hemoglobinogenic 2. Through GIT (argyrosis)

(hemosiderin, hematoidin,

myoglobin, hemoglobin, 3. Through respiratory tract

bilirubin, porphyrins) Coniosis (anthracosis,siderosis)

3. Uncertain origin Coniofibrosis (SiO2, asbestos)

(melanosis coli) Coniotoxicosis, alergosis (Cu,

Va, Zn...)

Endogenous pigments

Autogenic pigments

Melanin – corpuscular pigment

- formed in melanosome (organelle), ...oculocutaneous melanin

melanocytes derived from neuroectoderm

- color of skin, hair, iris, retina, areas of high pigmentation

- synthetized from tyrosin by tyrosinase (dopaoxidase)

- regulated by MSH

- deposited in the basal layer of skin

Neuromelanin – yellowish-brown

- in catecholergic neurons (subst. nigra, locus coeruleus)

Melanin

Hyperpigmentation

- local (melanodermia) – solar, gestational (chloasma), hormonal,

cosmetic (bergamot oil), chlorpromasin,

ephelides, café-au-lait

- diffuse – Addison disease (graphit spots – gingiva),

adrenal insuff. (tbc, lues, metastases...), cachexia

- local pigmented spots – lentigo, cafe au lait

Melanin

Hypopigmentation

= pathological lack of pigment

- inborn – local, generalized (albinism)

OCA – oculocutaneous albinism

(autosomal recessive)

in Chediac-Higashi sy (defective granules -

- melanosomes formation)

- acquired – pigmentation defect – loss of melanocytes in

the skin – depigmentation = vitiligo

- local loss of pigmentation after skin disease

(psoriasis, lues) = leukoderma

Lipofuscin – brown pigment accumulating in cells of CNS,

liver, muscle, adrenals...

- derives from membrane constituents

- increasing with age, in atrophy

Lipochrom – yellowish – adipous tissue – carotens (exogenous)

Ochronosis – tyrosin – homogentic ac. – urine, cartilage (brown)

Ceroid - lysosomal pigment from fatty acids

Endogenous pigments

Hemoglobinogenic pigments-splitting process of hemoglobin from Er hemolysis

- extravascular (hemorrhage, hemorrhagic

infarcts, infarceration, inflammations...)

... Bilirubin – yellow around hematoma

... Hemosiderin – in Mf, complex with lipoproteins+Fe

(siderophages – lungs, bone m., spleen...)

... Hematin, hematoidin – Hb oxidation in low pH (dark)

centers of large hematomas, stomach

- intravascular (hemolytic anemia, transfusion,

hemolytic toxins, saponins)

Hemoglobinemia – quick hemolysis ... hemoglobinemia,

Hb – urine ... Nephrosis

-mechanically – valve prosthesis, marching,

-osmotic – distiled water administration

-toxic – saponins, glycerine, bacterial toxins, ...

-immunologic – autoimmune, complement

Hemosiderosis – consequence of repeated or lasting hemolysis

- hemosiderin deposition in Mf, liver, spleen

- reactive fibrosis

Hemochromatosis – increased absorption Fe in duodenum

- deposition in pancreas (bras diabetes), cirrhosis, salivary

glands, plexus chorioideus

Hyperbilirubinemia – yellow skin, mucosas, sclera

= icterus

Icterus-bilirubin in serum

Dynamic icterus – hemolytic, extrahepatal ...excessive formation of

nonconjugated bilirubin by hemolysis

–– bile normaly flows into duodenum

-infectious diseases (sepsis), hemolytic toxins, antibody mediated

(fetal erythroblastosis), autoimmune diseases, resorption of

large hematomas, ...

= flavine icterus (yellowish green)

Hepatotoxic icterus – (hepatocellular) ...damage to liver parenchyma

- impared conjugation and excretion of billirubin into bile

...acute/chronic hepatitis, leptospirosis, yellow feever, hepatotoxins,

medicines,

= rubine icterus (yellowish orange)

Obstruction icterus – (mechanical)

-blockage of intrahepatic/extrahepatic bile ducts

(tu pancreas, LN, parasites, congenital atresion, autoimmune...)

... resorption of accumulated bile – conjugated billirubin

acholic intestinal content, normal urine

Long lasting process – cholestatic cirrhosis, cholemic nephrosis

= verdine icterus (greenish) + itching, pruritus

Porphyria-congenital enzymopathy – accumulation of porphyrins (from pyrols)

- defect of decarboxylation of porphyrins

Hepatal form – usually acute course, chronic form =

= porphyria curtanea tarda (bullous disease)

= liver cirrhosis

Erythropoietic form – defective metabolism of erythroblasts in BM

= bullous dermatitis, photosensitive skin

Exogenous pigments

Skin and mucosatraumatic tatoo – dust, pigments at accidents, miners

decorative tatoo – china ink

siderosis – around iron fragments (skin siderosis)

microbial stains – P. aeruginosa (blue), Aspergilus f. (green)

GITSome metals and their salts

argyrosis – silver from medication, amalgam

chrysocyanosis – colloid Au

Respiratory tract< 5 um ... lung alveoli

> 5 um ... caught in air ways

Simple conioses- biologically inactive, insoluble, not resorptive

Anthracosis – most frequent – amorphous carbon (soot, coal,

smoke, tabakism...)

- may limit lymph flow from lungs (complication in inflammation)

Siderosis – professional exposition (paper mill, mechanics, welding...)

Tabacosis – tabacco dust (brown lung, little pathology)

Coniofibrosis- coniosis accompanied by fibrosis

Silicosis – SiO2

-most serious professional disease

=SiO2 phagocyted in alveoli, release of lysozomal enzymes -

- damage to tissue, reparatory fibrosis

Silicosis - reticular stage

- nodular stage

- diffuse fibrosis

... overload of right heart, heart failure; familial predisposition

Coniofibrosis- coniosis accompanied by fibrosis

Asbestosis

- fibrosis, asbestos (ferruginous) bodies

- adenoCa

- mesothelioma.

Aluminosis

Beryliosis