Zn/Cu/Mn Flashcards
what is the Zn RDA?
15mg/day males
12mg/day females
increase w/ pregnancy + lactation
what are food sources of Zn?
seafood, red/organ meta, whole grains
what is the Cu RDA?
1.5-3.0 mg/day
same for male/female
what are food sources of Cu?
organ meat, nuts, shellfish
what is the Mn RDA?
2.0-5.0 mg/day
male slightly higher than female
what are food sources of Mn?
whole grains, nuts, tea
how are Zn/Cu/Mn status assessed?
no reliable functional assessment or markers
- natural fluctuations in [plasma]
- ceruplasmin (Cu assessment) sensitive to inflammation
how do Zn/Cu/Mn deficiencies differ?
Zn: alopecia, immune dysfunction, poor wound healing, impaired IGF-1, decreased thyroid size
Cu: low aortic elasticity, effects matrices surrounding organs
Mn: abnormal bone, offspring malformation, poor growth
what are the functions of Zn?
- strong Lewis acid, more abundant in cell
- structural role in cytosol and extracellular SOD
- stabilizes DNA sequence folding of a loop/finger
- immunity: lymphocyte maintenance
what does SOD do + conditions for it to occur
- detoxifies super oxides through redox reactions that require Cu/ZN-SOD or Mn/Zn-SOD
what are the functions of Cu?
- strongest Lewis acid, less abundant in cell
- Fe2 to Fe3 oxidation for delivery to peripheral tissues (Cu bound as ceruloplasmin)
- bone mineralization: provides collagen matrix via lysyl oxidase
- immunity: neutrophil/granulocyte maintenance, stem cell maturation
what are the functions of Mn?
- skeletal development: required for glycosaminoglycan synthesis which provides scaffolding for elongation
what are the 4 roles of metalloenzymes?
- signaling
- structural
- catalytic
- regulatory
how is Zn transported?
- absorbed in small intestine via carrier mediated (ZnT5B) + regulated diffusion (ZIP4)
- bound/stored within cell by metallothionein
- bound to albumin and transported to liver
- re-packaged and bound to a-2-macroglobulin
how is Cu transported?
- absorbed in small intestine via carrier mediated + regulated diffusion
- bound/stored within cell by metallothionein
- bound to albumin and transported to liver
- repackaged into ceruloplasmin
how is Mn transported?
- absorbed in small intestine via carrier mediated + regulated diffusion
- bound directly to a-2-macroglobulin for transport to liver
what is some overlap between Zn/Cu/Mn?
- are all considered metalloenzymes
- Zn + Cu binding inhibited by Ca
- no large pools of storage
- most lost through feces via intestinal cell sloughing/bile incorporation
what are Cu toxicity symptoms
- Wilson’s disease: accumulation in liver + brain = liver disease + neuropsychiatric symptoms
- Menkes syndrome: transport effected = deficiency
