人和大鼠脊髓内的心钠素样物质

应用特异的心钠素免疫金银染色和放射免疫测定法,证明在人和大鼠脊髓内亦存在有心钠素样物质。心钠素免疫金银染色发现在人脊髓各段均有心钠素免疫反应阳性的神经元广泛分布。这些神经元主要位于脊髓腹角,同时脊髓背角和侧角亦有少量分布。应用对照吸收试验,其心钠素免疫反应阳性颗粒便消失或明显减少。心钠素放射免疫测定发现,从大鼠颈髓到胸、腰、骶髓均有心钠素样物质存在,其中以骶髓含量最高,为21.9±4.48ng/g组织;腰髓次之,为3.78±0.74ng/g组织;颈、胸髓含量最低,分别为0.58±0.14和0.46±0.21ng/g组织。应用凝胶过滤和高压液相层析证明,大鼠脊髓中心钠素亦以多分子形式存在,但以28个氨基酸的大鼠心房利纳多肽(rANP)为主。此外,对在体大鼠脊髓蛛网膜下腔灌流研究发现,高钾去极化刺激可使大鼠脊髓心钠素样物质释放。

ATRIAL NATRIURETIC POLYPEPTIDE IN THE HUMAN AND RAT SPINAL CORD

The widespread distribution of atrial natriuretic polypeptide (ANP) immunoreactive material was demonstrated in the human and rat spinal cord, using specific immunogold-silver staining technique and radioimmunoassay. Immunogold-silver staining studies showed that ANP immunoreactive neurons were quite prevalent in the human spinal cord. ANP immunoreactive neurons were largely found in the ventral horn and less in the dorsal and lateral horns. ANP immunoreactive material was absent with anti-ANP serum preabsorbed with ANP. In rats, radioimmunoassay demonstrated that ANP immunoreactive material was present in whole spinal cord. The highest concentration was found in the sacral spinal cord (21.9 +/- 4.48 ng/g tissue), the moderate in the lumbar (3.78 +/- 0.74 ng/g tissue) and the lowest in the cervical and thoracic (0.58 +/- 0.14 and 0.46 +/- 0.21 ng/g tissue, respectively). Gel chromatography and reverse-phase HPLC revealed multiple molecular forms in the rat spinal cord, but the main molecular form was the 28 amino acid rANP. In vivo study showed that ANP was released from the rat spinal cord by depolarizing concentration of potassium.