title: Amperometric determination of choline released from rat submandibular gland acinar cells using a choline oxidase biosensor.
abstract: A choline (CHO) biosensor based on the determination of H(2)O(2) generated at the electrode surface by the enzyme choline oxidase (CHOx) was developed. The biosensor consisted of CHOx retained onto a horseradish peroxidase (HRP) immobilized solid carbon paste electrode (sCPE). The HRPsCPE contained the molecule phenothiazine as redox mediator and CHOx was physically retained on the electrode surface using a dialysis membrane. Several parameters have been studied such as, mediator amount, influence of applied potential, etc. The CHO measurements were performed in 0.1 M phosphate buffer, pH 7.4. Amperometric detection of CHO was realized at an applied potential of 0.0 mV vs Ag/AgCl. The response is linear over the concentration range 5.0x10(-7)-7.0x10(-5) M, with a detection limit of 1.0x10(-7) M. This biosensor was used to detect choline released from phosphatidylcholine (PC) by phospholipase D (PLD) in isolated rat salivary gland cells stimulated by a purinergic agonist (ATP).
authors.affiliation: Service de chimie analytique instrumentale et de bioélectrochimie, Université Libre de Bruxelles, Institut de Pharmacie, Campus Plaine, 1050 Bruxelles, Belgium.
authors.forename: S Serradilla
authors.initials: SS
authors.lastname: Razola
authors.forename: S
authors.initials: S
authors.lastname: Pochet
authors.forename: K
authors.initials: K
authors.lastname: Grosfils
authors.forename: J M
authors.initials: JM
authors.lastname: Kauffmann
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology; D000429:Alcohol Oxidoreductases / Q000737:chemistry; D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D002794:Choline / Q000032:analysis* / Q000737:chemistry / Q000493:pharmacokinetics*; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D008567:Membranes, Artificial; D010713:Phosphatidylcholines / Q000378:metabolism; D010740:Phospholipases / Q000032:analysis / Q000378:metabolism; D051381:Rats; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013363:Submandibular Gland / Q000187:drug effects / Q000378:metabolism*; D013696:Temperature
chemical_list: D020099:Coated Materials, Biocompatible; D008567:Membranes, Artificial; D010713:Phosphatidylcholines; D000255:Adenosine Triphosphate; D000429:Alcohol Oxidoreductases; C019888:choline oxidase; D010740:Phospholipases; D002794:Choline