5-羟色氨_(2A)受体对新生大鼠延髓脑片节律性呼吸放电的调制作用

Modulation of 5-HT_(2A) receptors on rhythmic respiration discharge activity in the transverse medullary slice of neonatal rats

目的探讨5-羟色氨2A(5-HT2A)受体对新生大鼠延髓脑片节律性呼吸放电的调制作用。方法制作新生大鼠离体延髓脑片标本,给予灌流恒温改良Kreb′s液,记录舌下神经根呼吸相关节律性放电活动(RRDA)。标本分2组:第1组使用含5-HT2A受体特异激动剂2,5-二甲氧基-4-碘苯基丙烷(DO I)的Kreb′s液灌流脑片,观察其对RRDA的影响;第2组使用含5-HT2A受体特异拮抗剂酮舍林的Kreb′s液灌流脑片,观察其对RRDA的影响。结果DO I延长RRDA吸气放电时程(TI)、缩短呼气时程(TE)、缩短呼吸周期(RC)、增强RRDA放电积分幅度(IA),对RRDA有兴奋作用(P<0.01)。酮舍林缩短RRDA的TI,延长TE和RC、减弱IA,对RRDA有抑制作用(P<0.01)。结论5-HT2A受体参与了新生大鼠基本呼吸节律的产生和调节。

Objective To study the modulation of 5-HT2A receptors on rhythmic respiration discharging activity in the transverse medullary slices of neonatal rats. Methods The transverse medullary slices of neonatal rats were made and perfused with homothermal and improved Kreb/s liquid, the respiratory-related rhythmic discharge activity（RRDA） of hypoglossal nerve root was recorded. The slices were divided into two groups. In group I ,the slices were perfused with 5-HT2A receptor excitomotory 1-（2,5-dimethoxy-4-iodophenyl）-2 -aminopropane （DOI） dissolved in modified Kreb＇s solution. In group Ⅱ,the slices were perfused with ketanserine specific antagonist of 5-HT2A receptor. The effects of DOI and ketanserine on RRDA were observed. Resuits DOI could increase RRDA, prolonged inspiratory time （TI）, shortened expiratory time （TE） and respiratory cycle （ RC）, increased integral amplitude （IA） of RRDA （ P 〈 0.01 ）. Ketanserina could inhibit RRDA, shortened TI, prolonged TE and RC, decreased IA（ P 〈 0.01 ）. Conclusion 5-HT2A receptor play an important role in the generation and modulation of RRDA in the transverse medullary slice of neonatal rats.