Seminal plasma is mainly secreted from the seminal vesicles and is characterized by relatively high concentrations of fructose. Seminal fructose levels are often elevated in patients with oligospermia or azoospermia. Measurement of fructose in seminal plasma can provide information concerning the activity of the seminal vesicles and pathology of the male reproductive tract which may be responsible for cases of infertility. A method for simultaneous assay of glucose and fructose in semen using differential pH-measurement is described. The method is based on a phosphorylation of glucose using glucokinase, followed by fructose phosphorylation via hexokinase. The resulting ATP consumption causes a pH reduction measurable by the system. Assay reaction conditions are the following: phosphate buffer 17.7 mmol/L pH 7.5, MgCl2 3 mmol/L, ATP 2.2 mmol/L, glucokinase 1.3 KU/L and hexokinase 7.77 KU/L in the reaction mixture. Glucokinase is added as first starter, reaction is complete within 30 sec and the pH variation is used for glucose measurement, hexokinase is then added as second starter. With these assay conditions we obtained a linear response up to 1000 mg/dL of fructose with no interference from other carbohydrates. The method is precise: CV within run = 1.1% and CV between runs = 1.6%. The correlation with a spectrophotometric method gave the following results: n = 43, r = 0.9989, y = 0.987x + 3.66. Fructose levels and fructolysis rate in a group of patients with normospermia, oligospermia and astenospermia were studied. Fructolysis correlated well with other seminal markers of fertility.
|Translated title of the contribution||Simultaneous measurement of glucose and fructose in seminal plasma using a differential pH technique|
|Number of pages||8|
|Journal||Giornale Italiano di Chimica Clinica|
|Publication status||Published - 1995|
ASJC Scopus subject areas
- Clinical Biochemistry