Identification and characterization of cyclo(His-Pro)-like immunoreactivity in amniotic fluid.
Amniotic fluid (AF) from 25 term pregnancies was analyzed for cyclo(His-Pro)-like immunoreactivity (CHP-LI). CHP-LI was detected in all AF samples and was indistinguishable from synthetic CHP by immunoidentity, by gel chromatography on Sephadex G-25, and by high pressure liquid chromatography. The mean concentration of CHP-LI in AF was 13,622 +/- 1288 pg/ml (+/- SE) and concentrations were not altered by maternal labor. Plasma concentrations of CHP-LI were similar in 4 pregnant and 4 control subjects [2260 +/- 432 pg/ml vs. 2162 +/- 419 pg/ml (+/- SE), respectively]. We conclude that 1) CHP-LI is readily detected in AF from term pregnancies and is indistinguishable from synthetic CHP, and 2) concentrations of CHP-LI in human AF are significantly higher than concentrations of maternal plasma CHP-LI, suggesting CHP AF originates by mechanisms other than diffusion from maternal plasma.
Department of Medicine, LSU Medical Center, New Orleans 70112.
C W
CW
Hilton
G C
GC
Wolf
J F
JF
Wilber
C
C
Prasad
D
D
Rogers
D000653:Amniotic Fluid / Q000032:analysis*; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006801:Humans; D010456:Peptides, Cyclic / Q000032:analysis* / Q000097:blood; D010879:Piperazines / Q000032:analysis* / Q000097:blood; D011247:Pregnancy; D011863:Radioimmunoassay / Q000379:methods
D010456:Peptides, Cyclic; D010879:Piperazines; C015924:histidyl-proline diketopiperazine