Simple, rapid enzymatic determination of glycerophosphocholine in human seminal plasma.
We have devised a new enzymatic determination of sn-glycero-3-phosphocholine (GPC) in human seminal plasma. This is based on GPC hydrolysis by a phosphodiesterase (PDE), free choline being then determined by the choline oxidase method. The whole procedure involves a first incubation in the presence of choline oxidase and catalase, to eliminate the excess of choline present in seminal plasma (10-fold, compared with GPC). Absorbance and concentration are linearly related up to at least 100 nmol per assay, analytical recovery ranges between 89% and 105%, and intra- and interassay CVs are 3.2% and 5.6%, respectively, at the highest substrate concentration. Using this procedure, we found seminal plasma from 21 fertile men to contain 5.22 (SD 3.33) mumol per ejaculate--within the same range as previously reported values obtained chromatographically. After vasectomy, GPC in seminal plasma decreased to 28% of its original value, as determined in 10 volunteers. Thus this new method displays appropriate characteristics of specificity, reliability, and convenience, allowing its use in routine evaluation of male fertility.
Chap
H J
HJ
Laboratoire de Biochimie III, Hôpital La Grave, Toulouse, France.
Moatti
J P
JP
Mieusset
R
R
Nieto
M
M
Laneelle
G
G
Bennet
P J
PJ
Mansat
A
A
Pontonnier
F
F
Douste-Blazy
L
L
D000429:Alcohol Oxidoreductases / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D002794:Choline / Q000032:analysis / Q000378:metabolism; D005997:Glycerylphosphorylcholine / Q000032:analysis* / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis; D007248:Infertility, Male / Q000378:metabolism; D008297:Male; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism; D010767:Phosphorylcholine / Q000032:analysis; D012661:Semen / Q000032:analysis*; D013053:Spectrophotometry; D014659:Vasectomy
D010767:Phosphorylcholine; D005997:Glycerylphosphorylcholine; D000429:Alcohol Oxidoreductases; C019888:choline oxidase; D002374:Catalase; D010727:Phosphoric Diester Hydrolases; D002794:Choline