Myocardial beta-adrenoceptor Function after brain death

移植后心功能不全，对儿茶酚胺反应差，可能部分与外源性儿茶酚胺用于脑死亡(BD)供体维持有关。本实验采用犬BD颅内高压模型，观察了心肌β-肾上腺素能受体(BAR)的变化。为维持BD后平均动脉压在60 mm Hg以上(组I)或肾上腺素(EPI)0.4~1.3ug/kg/min(组II)。分别于造模后3h(I-3hr，II-3hr)或6h(I-6hr，II-6hr)测定血EPI水平和心肌条密度(I-Iodocyanopindlol)。n组EPI水平条密度条亲和力：(ng/ml)(fmol/MQ)(PM)对照4 0.12；+-gt；0.05 68.9&lt；+-gt；6.6 17.9&lt；+mini-3hr 4 0.09&lt；0.04 64.7&lt；正--负；5.8 18.4&lt；+-mini-6hr 4 N.D.72.3&lt；+--负&gt；6.1 18.1&lt；+--II-3hr 4 4.93&lt；+-&gt；0.67 59.2&lt；+-&gt；5.9 19.0&lt；+-mini-6hr 4 7.04&lt；+-负&gt；0.83*41.0&lt；+--&gt；5.0±18.6+-min(*：P&lt；0.05 vs II-3h，#：P&lt；0.05 vs其他)提示脑死亡供体应用大剂量儿茶酚胺后，心肌条密度降低，这可能是心脏移植供心功能的部分原因。

Post-transplant cardiac dysfunction with poor response to catecholamine may partly relate to the exogenous catecholamine used for brain-dead (BD) donor maintenance. In this experimental study using canine BD model of intracranial hypertension, alterations in myocardial beta-adrenergic receptor (BAR) were investigated. To maintain the mean arterial pressure higher than 60 mmhg after BD massive crystalloid fluid infusion (Group I) or 0.4 - 1.3 ug/kg/min of epinephrine (EPI, Group II) were used. After 3 hour (I-3hr, II-3hr) or 6 hour (I-6hr, II-6hr) of DD, blood EPI level and myocardial BAR(^<125>I-iodocyanopindlol binding) were measured.group n EPI level BAR density BAR affinity.(ng/ml) (fmol/mq) (PM)control 4 0.12<plus-minus>0.05 68.9<plus-minus>6.6 17.9<plus-minI-3hr 4 0.09<plus-minus>0.04 64.7<plus-minus>5.8 18.4<plus-minI-6hr 4 N. D. 72.3<plus-minus>6.1 18.1<plus-minusII-3hr 4 4.93<plus-minus>0.67 59.2<plus-minus>5.9 19.0<plus-minII-6hr 4 7.04<plus-minus>0.83* 41.0<plus-minus>5.0# 18.6<plus-min(* : p<0.05 vs II-3h, # : P<0.05 vs others)The result suggests that myocardial BAR density may reduce after use of high dose catecholamine in brain-dead donor and this might be partly responsible for donor heart function in heart transplantation.