Interleukin-6 in human milk.
Interleukin-6 (IL-6) in human milk collected during the first 2 days of lactation was investigated by a competitive radioimmunoassay (RIA) and column chromatography. The concentrations of IL-6 in the aqueous phase of fresh human milk were 151 +/- 89 pg/ml. The concentrations of IL-6 in milk increased after storage at 4 degrees C and decreased after storage at -20 degrees C (P < 0.01). Column chromatography revealed two molecular weight peaks of IL-6 in human milk, the first > or = 100 kDa and the second between 25 and 30 kDa. The 25-30-kDa peak corresponded to known isoforms of human IL-6 and to the elution pattern for 125I-labeled recombinant human IL-6, whereas the higher molecular weight peak may be in keeping with a bound or compartmentalized form of that cytokine. The precise molecular forms of this protein, the compartmentalization of or binding proteins for this cytokine and the in vivo effects of IL-6 in human milk upon the mammary gland or the recipient infant remain to be explored.
Rudloff
H E
HE
Department of Pediatrics, University of Texas Medical Branch, Galveston 77555-0369.
Schmalstieg
F C
FC
Palkowetz
K H
KH
Paszkiewicz
E J
EJ
Goldman
A S
AS
D000293:Adolescent; D000328:Adult; D002850:Chromatography, Gel; D003080:Cold Temperature / Q000009:adverse effects; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000032:analysis*; D008894:Milk Proteins / Q000737:chemistry / Q000302:isolation & purification; D008895:Milk, Human / Q000737:chemistry*; D008970:Molecular Weight; D011863:Radioimmunoassay
D015850:Interleukin-6; D008894:Milk Proteins