Zn++		
• 2 g in organism, mainly in muscles, kidneys and bones	prostatic gland,	
• intracelular element		
• reference values   Zn/S =	700 10-	-1700 jig/I 25 umol/l
• RDI       about 12 mg/d		
• alimentary sources: sea fish, meal, grains, seeds and nuts                                             2		
Absorption • 20%	
• duodenum and jejunum,	competition with Cu
• | in zinc deficiency, t in t zinc intake, but within 4 days balí    e occurs again	
Excretion	
• Faeces: 10 mg/d, unabsor - I, bile and pancreatic	
• Urine: 0.3 - 0.6 mg/d	
• Perspiration: 2-3 mg/d	3
Transport and distribution in
organism
•  in blood binds albumin (t>£>%) and macroglobulin, IC metalothionein
•  75-88% of Zn of blood is in eres
•  not stored in the liver
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About 200 of zinc containing
enzymes
• alcoholdehydrogenase, LD, GMD, SOD, AST, DNA- and RNA-polymerases, ALP, ACE, kolagenase, karboxypeptidases, aldolases, carbonan hyd rase A (first described Zn enzyme, 193(3), levulinate dehydratase, AMS, neutral proteases, thymidinkinase,.....
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2 02- + 2H+   ->   02 + H202
•  SOD 1 (cytoplasm), EC-SOD: contains Cu and Zn
•  Zn2+ - stabilisation function
•  Cu2+ - catalytic function
Zinc significance
•  stabilisation of protein, RNA, DNA, ribosomes and hormone-receptor complexes structure
•  stabilisation of cell membranes
•  facilitates healing
•  facilitates glucose absorption and linkage of insulin receptors to hepatocytes
•  antioxidative protection (SOD)
•  needed for cell proliferation, production of connective tissue and spermatogenesis
•  facilitates trombocytes adhesion and agregation
•  needed for cell imunity, increases infection resistance
Deficiency	
• 400 - 700 ug/l weak	
• < 400 ug/l strong	
• inborn	
• obtained	
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Acrodermatitis enteropathica
•  = Danbolt disease, AR heredity
•  clinically manifests with start of cow-milk feeding
•  symptoms:*skin rash (red, ichthyotic; extremities)
"cheilitis, stomatitis, glositis *bl isters, alopecia *chronic diarrhea and cachexy "affection of eyes and nails "immunity disorders
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Causes of obtained deficiency
•  malnutrition (vegans) ► malabsorption
•  insufficient supplementation in long-term parenteral nutrition
» f loss during catabolism or burns
•  deficiency in penicilamine, deferoxamine or corticosteroids therapy
•  t requirement in growth, pregnancy, breastfeeding
Symptoms
Growth and sexual development defects
Impair wound healing, skin defects, red skin
Imunity disorders (T-cells) with }    fection liability
I glc tolerance
Diarrhea, dysorexia
Taste and smell impairment
Spleen and liver enlargement
Night blindness
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Toxicity
acute intoxication: nausea, emesis, diarrhea, fever, muscle pain
chronic: copper deficiency (intestinal absorption and transport proteins competition)
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Clinical applications
•  healing of bums and skin defects, such as decubiti or crural ulcers
•  therapy of Wilson's disease
•  therapy of acne and herpetifonm dermatitis
•  zinc gluconate, ZnS04
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