[A cystine-containing short-chain peptide as a potential cystine source for parenteral nutrition].
For the first time, in vivo utilization of two highly soluble and stable cystine containing synthetic short chain peptides, N,N'-bis-L-alanyl-L,L-cystine and N,N'-bis-glycyl-L,L-cystine, was investigated in adult rats. Within 5 min after an intravenous bolus, blood samples were drawn (inferior vena cava) and plasma amino acid and peptide levels were determined using RP-HPLC (precolumn derivatization with 1-dimethylaminonaphthalene-5-sulfonylchloride). Both peptides were rapidly cleared from plasma (estimated elimination time: 4 min for the glycyl peptide and less than 2 min for the alanyl peptide). The initial high amounts of N-L-alanyl-L,L-cystine and N-glycyl-L,L-cystine as well as the prompt increase of the constituent free amino acids alanine, glycine and cystine strongly suggest that the peptide disappearance is mainly due to a very fast two-step hydrolysis in the extracellular compartment, presumably catalyzed by soluble and/or plasma membrane bound peptidases. The observed rapid hydrolysis may serve as first evidence that short chain peptides with C-terminal cystine residue may represent efficient sources of free cystine in parenteral nutrition.
Pollack
L
L
Institut für Biologische Chemie und Ernährungswissenschaft, Universität Hohenheim, Stuttgart.
Stehle
P
P
Albers
S
S
Fürst
P
P
D000409:Alanine / Q000378:metabolism; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003553:Cystine / Q000008:administration & dosage* / Q000378:metabolism; D005998:Glycine / Q000378:metabolism; D006868:Hydrolysis; D007262:Infusions, Intravenous; D008297:Male; D010288:Parenteral Nutrition; D010455:Peptides / Q000008:administration & dosage / Q000493:pharmacokinetics*; D051381:Rats; D011919:Rats, Inbred Strains
D010455:Peptides; D003553:Cystine; D000409:Alanine; D005998:Glycine
Cystinhaltige kurzkettige Peptide als potentielle Cystinquelle in der parenteralen Ernährung.