Establishment of a reliable extraction method of estrone sulfate from bovine plasma for detection of the peripheral level during the regular estrous cycle by radioimmunoassay.
A simple extraction and assay technique of estrone sulfate in bovine blood was developed with the object of detecting the peripheral level of estrone sulfate in a normal estrous cycle or in early pregnancy. Estrone sulfate in bovine plasma was extracted with a small reversed phase cartridge. The steroid conjugate retained in the cartridge was eluted with 40% (v/v) methanol. Estrone sulfate was separately recovered from other steroids by the stepwise increase in methanol concentration in the elution solvent. The recoveries of estrone sulfate eluted with 40% methanol were more than 90%, irrespective of the applied plasma volume. The concentration measured by radioimmunoassay with the eluent of 40% methanol was consistent for plasma extraction volumes of 0.5-2.0 ml. The change of estrone sulfate in bovine peripheral plasma during the regular estrous cycle was determined with a small reversed phase cartridge for extraction and 40% methanol for elution. The change in estrone sulfate was found to be similar to the change of estrone and estradiol-17 beta. The concentration of estrone sulfate was not higher than that of both estrogens in cattle.
Hirako
M
M
Department of Animal Reproduction, National Institue of Animal Industry, Ibaraki, Japan.
Takahashi
H
H
Domeki
I
I
D000818:Animals; D000906:Antibodies / Q000097:blood / Q000276:immunology; D002417:Cattle / Q000097:blood*; D002851:Chromatography, High Pressure Liquid / Q000379:methods / Q000662:veterinary; D004958:Estradiol / Q000097:blood; D004966:Estrogens, Conjugated (USP) / Q000097:blood / Q000276:immunology / Q000302:isolation & purification; D004970:Estrone / Q000031:analogs & derivatives* / Q000097:blood / Q000276:immunology / Q000302:isolation & purification; D004971:Estrus / Q000097:blood*; D005260:Female; D006863:Hydrogen-Ion Concentration; D000432:Methanol / Q000737:chemistry; D011247:Pregnancy; D011374:Progesterone / Q000097:blood; D011863:Radioimmunoassay / Q000379:methods / Q000662:veterinary*
D000906:Antibodies; D004966:Estrogens, Conjugated (USP); D004970:Estrone; D011374:Progesterone; D004958:Estradiol; C017296:estrone sulfate; D000432:Methanol