Enzyme immunoassay of a substance P-like immunoreactive substance in human plasma and saliva.
A sensitive and specific double-antibody enzyme immunoassay (EIA) for a substance P (SP)-like immunoreactive substance (SP-IS) was developed. For competitive reactions, the SP-antibody was incubated with SP standard (or sample) and beta-D-galactosidase labeled Tyr8-SP (delayed addition). Free and antibody-bound enzyme hapten were separated by using an anti-rabbit immunoglobulin G coated immunoplate. Activity of the enzyme on the plate was fluorometrically determined. The present immunoassay allows detection of 0.4 to 10 fmol/well of SP. Using the present EIA, SP-ISs in human saliva and plasma were determined. The level of SP-IS in human saliva was about 7 pmol/l, which was almost three times higher than that in human plasma.
Takeyama
M
M
Department of Hospital Pharmacy, Medical College of Oita, Japan.
Mori
K
K
Takayama
F
F
Kondo
K
K
Kitagawa
K
K
Fujii
N
N
D002851:Chromatography, High Pressure Liquid; D006801:Humans; D007124:Immunoenzyme Techniques; D012463:Saliva / Q000737:chemistry*; D013373:Substance P / Q000032:analysis* / Q000097:blood / Q000276:immunology
D013373:Substance P