title: Simultaneous analysis of vascular norepinephrine and ATP release using an integrated microfluidic system.
abstract: Sympathetic nerves are known to release three neurotransmitters: norepinephrine, ATP, and neuropeptide Y that play a role in controlling vascular tone. This paper focuses on the co-release of norepinephrine and ATP from the mesenteric arterial sympathetic nerves of the rat.
  
  
  
  In this paper, a quantification technique is described that allows simultaneous detection of norepinephrine and ATP in a near-real-time fashion from the isolated perfused mesenteric arterial bed of the rat. Simultaneous detection is enabled with 3-D printing technology, which is shown to help integrate the perfusate with different detection methods (norepinephrine by microchip-based amperometery and ATP by on-line chemiluminescence).
  
  
  
  Stimulated levels relative to basal levels of norepinephrine and ATP were found to be 363nM and 125nM, respectively (n=6). The limit of detection for norepinephrine is 80nM using microchip-based amperometric detection. The LOD for on-line ATP detection using chemiluminescence is 35nM.
  
  
  
  In previous studies, the co-transmitters have been separated and detected with HPLC techniques. With HPLC, the samples from biological preparations have to be derivatized for ATP detection and require collection time before analysis. Thus real-time measurements are not made and the delay in analysis by HPLC can cause degradation.
  
  
  
  In conclusion, the method described in the paper can be used to successfully detect norepinephrine and ATP simultaneously and in a near-real-time fashion.
authors.affiliation: Department of Chemistry, Saint Louis University, St. Louis, MO 63103, United States.
authors.forename: Alexandra D
authors.initials: AD
authors.lastname: Townsend
authors.affiliation: Department of Pharmacology and Physiology, Saint Louis University School of Medicine, 1402 South Grand Blvd., St. Louis, MO 63104, United States.
authors.forename: Gerald H
authors.initials: GH
authors.lastname: Wilken
authors.affiliation: Department of Electrical and Computing Engineering, Saint Louis University, St. Louis, MO 63103, United States.
authors.forename: Kyle K
authors.initials: KK
authors.lastname: Mitchell
authors.affiliation: Department of Chemistry, Saint Louis University, St. Louis, MO 63103, United States.
authors.forename: R Scott
authors.initials: RS
authors.lastname: Martin
authors.affiliation: Department of Pharmacology and Physiology, Saint Louis University School of Medicine, 1402 South Grand Blvd., St. Louis, MO 63104, United States. Electronic address: macarthu@slu.edu.
authors.forename: Heather
authors.initials: H
authors.lastname: Macarthur
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004129:Dimethylpolysiloxanes; D004566:Electrodes; D004867:Equipment Design; D056656:Lab-On-A-Chip Devices; D008163:Luminescent Measurements / Q000295:instrumentation* / Q000379:methods*; D008297:Male; D008638:Mesenteric Arteries / Q000294:innervation / Q000378:metabolism; D044085:Microfluidics / Q000295:instrumentation / Q000379:methods*; D009638:Norepinephrine / Q000378:metabolism*; D009757:Nylons; D011137:Polystyrenes; D066330:Printing, Three-Dimensional; D017207:Rats, Sprague-Dawley; D013564:Sympathetic Nervous System / Q000378:metabolism; D046509:Tissue Culture Techniques
chemical_list: D004129:Dimethylpolysiloxanes; D009757:Nylons; D011137:Polystyrenes; C085707:poly(dimethylsiloxane)-polyamide copolymer; D000255:Adenosine Triphosphate; D009638:Norepinephrine
keywords: ATP; Amperometry; Chemiluminescence; Microfluidics; Norepinephrine