Lackie P M, Zuber C, Roth J
Department of Cell and Molecular Pathology, University of Zürich Medical School, Switzerland.
Differentiation. 1991 Jul;47(2):85-98. doi: 10.1111/j.1432-0436.1991.tb00226.x.
Developmental patterns of immunoreactivity for the neural cell adhesion molecule (N-CAM) and alpha 2.8-linked polysialic acid (PSA) were identified in embryonic and postnatal rat heart by immunocytochemistry and immunoblotting. Polyclonal antibodies against N-CAM and a monoclonal antibody which recognises only polymers of PSA with a chain length greater than eight units were used. Gold- and alkaline-phosphatase-labelled antibodies were used for detection. The N-CAM polypeptide isoform pattern seen by immunoblotting after endoneuraminidase treatment changed as development progressed. During embryonic development a 160-kDa polypeptide isoform was predominant. Around birth, 130-, 160- and 170-kDa polypeptide isoforms were found. The expression of the 130- and 170-kDa isoforms diminished until finally, in the adult, weak immunoreactivity for bands of 120-, 130- and 160-kDa was seen. In general the extent and intensity of PSA and N-CAM immunostaining in rat heart increased until birth and declined thereafter. Early in development prominent immunostaining for PSA and N-CAM was seen in the epicardium while later in development this area was only weakly stained. Initially myocardial cells, endocardial cells and some cells in the atrioventricular cushions were immunoreactive for both PSA and N-CAM. Later in development N-CAM immunostaining was more prominent than PSA immunoreactivity, reflecting a decrease in N-CAM polysialylation, which was also seen by immunoblotting. During innervation of the heart, nerve fibres were strongly immunostained for PSA and N-CAM, and this was the only immunostaining seen in adult heart.
通过免疫细胞化学和免疫印迹法，在胚胎期和出生后的大鼠心脏中鉴定了神经细胞黏附分子（N-CAM）和α2.8连接的多唾液酸（PSA）的免疫反应性发育模式。使用了针对N-CAM的多克隆抗体和仅识别链长大于8个单位的PSA聚合物的单克隆抗体。金标记和碱性磷酸酶标记的抗体用于检测。经神经氨酸酶处理后免疫印迹所见的N-CAM多肽同工型模式随发育进程而变化。在胚胎发育期间，160 kDa的多肽同工型占主导。出生前后，发现了130 kDa、160 kDa和170 kDa的多肽同工型。130 kDa和170 kDa同工型的表达逐渐减少，直到成年时，最终可见120 kDa、130 kDa和160 kDa条带的弱免疫反应性。一般来说，大鼠心脏中PSA和N-CAM免疫染色的范围和强度在出生前增加，此后下降。在发育早期，心外膜可见PSA和N-CAM的显著免疫染色，而在发育后期该区域仅弱染色。最初，心肌细胞、心内膜细胞和房室垫中的一些细胞对PSA和N-CAM均有免疫反应性。在发育后期，N-CAM免疫染色比PSA免疫反应性更显著，这反映了N-CAM多唾液酸化的减少，免疫印迹也可见此现象。在心脏神经支配期间，神经纤维对PSA和N-CAM有强烈免疫染色，这是成年心脏中唯一可见的免疫染色。
