Asari - Containing Serum On SD I_k Lateral Medullary Respiratory Neurons Of Rats

ObjectiveAsarum is aristolochiaceae perennial herb and pumice stone in commonuse. But the ancients have being believed that the capacity of asarum mustbe controlled in juice, and clinic doctor often follow that. In recent yearsthere are many research in that way. Along with the skill of serumpharmacology and chaff clamp presence, pumice stone and pharmacology ofcompound arrive a new epoch. This research adopt the adjoint of serumpharmacology and chaff clamp to observe the influence of serum containingAsarum on the delayed outward potassium channel in isolated SD rat'smedulla DRG neurons.Methods1 Make the blood serum containing AsarumFirst prepare certain Asarum root powder of density give SD rat toirritated stomach, twice a day, for eight days. The dosage of Asarum wereaccording to The Pharmacopeia of the People's republic of China(1stpart, public in 2005).2 The influence of serum containing Asarum on the I_k in isolated SDrat's medulla DRG neuronsSingle rat medulla DRG neurons were acutely isolated by enzymaticdigestion and mechanical dispersion from 1-3-day-old SD rat. Briefly,400-500 mm thick brain slices were cut from medulla. Then the medulla DRGregion was removed from the slice and incubated for 60min at 32℃inartificial cerebrospinal solution(ACSF), bubbled with 95％O₂+5％CO₂; andsuccessively transferred into D-hanks containing trypsin at 32℃for 15min. The brain fragments collected from several brain slices were treated by gentle pipetting using a fine glass tube.Whole-cell patch clamp recordings were made with EPC-10 doubleamplifier after the neurons were transferred to 35 mm culture dish filledwith 1.5-2ml ACSF with pipettes resistance of 1-5MΩ. Cells were held ata holding potential (HP) of-50mV, a series of 120 ms depolarizing stepsto-50mV-+30mV increment at 10mV each step and then stored in computerusing pulse+pulsefit(version8.74) software.For drug application, a series of ten micro-tubes (200μM) were gluedtogether side by side. Solutions were fed from independent reservoirs bygravity. The microtubes were shifted horizontally with a micro-mani-pulator for aligning the flow of solution from the tubes relative to thecells.ResultsThe experimental result make clear that at the same voltage, therewas no statistical difference between the normal serum and the controlgroup(P＞0.05); There was significant statistical difference between thenormal serum group and the serum containing Asarum (P＜0.05); There wassignificant statistical difference between the control group and theserum containing Asarum (P＜0.05). This result show that the serum conta-ining Asarum can activate the delayed outward potassium channel.Conclusion1 The serum containing Asarum can activate the delayed outwardpotassium channel in isolated SD rat' s medulla DRG neurons.2 The serum containing Asarum have little infection on thecharacteristic of the delayed outward potassium channel in isolated SDrat's medulla DRG neurons. 3 There have significant relationship between the influence ofAsarum on breathes and excitement of the inspiratory neurons on DRG.4 Asarum can boost ion concentration of potassium besides cell, leadwithering of breath and correlate breath neuron cell and palsying breathsystem.