title: Characterization and application of microdialysis probes with an active exchange length compatible with small-size brain nuclei in the rat.
abstract: We communicated the construction, characterization and application of microdialysis probes with an active exchange length that is suitable for experiments involving small-size nuclei in rat brain. Using substance P (SP) as the test substance, we determined that probes with an active exchange length of 180-200 microns exhibited an in vitro recovery of 14.2 +/- 0.8% and in vivo recovery at the nucleus tractus solitarii (NTS) of 24.9 +/- 1.7% for the undecapeptide, calibrated at an infusion rate of 1 microliter/min. We also demonstrated that microinfusion of SP via these probes into the NTS allowed for a correlation of changes in tissue levels of both SP (exogenous substance) and norepinephrine (endogenous substance) with alterations in baroreceptor reflex responses (physiologic phenomenon).
authors.affiliation: Department of Anesthesiology, National Yang-Ming Medical College, Taipei, Taiwan, ROC.
authors.forename: M Y
authors.initials: MY
authors.lastname: Tsou
authors.forename: W B
authors.initials: WB
authors.lastname: Len
authors.forename: A Y
authors.initials: AY
authors.lastname: Chang
authors.forename: J Y
authors.initials: JY
authors.lastname: Chan
authors.forename: T Y
authors.initials: TY
authors.lastname: Lee
authors.forename: S H
authors.initials: SH
authors.lastname: Chan
mesh_terms: D000818:Animals; D017704:Baroreflex / Q000187:drug effects; D001921:Brain / Q000033:anatomy & histology / Q000378:metabolism*; D004867:Equipment Design; D007263:Infusions, Parenteral / Q000295:instrumentation / Q000379:methods; D008832:Microchemistry / Q000379:methods; D017551:Microdialysis / Q000295:instrumentation* / Q000379:methods; D009638:Norepinephrine / Q000378:metabolism*; D051381:Rats; D012044:Regression Analysis; D017552:Solitary Nucleus / Q000378:metabolism*; D013373:Substance P / Q000008:administration & dosage* / Q000378:metabolism / Q000494:pharmacology
chemical_list: D013373:Substance P; D009638:Norepinephrine