大鼠生后垂体前叶P物质免疫反应阳性神经纤维的发育变化

The developmental changes of substance P immunoreactive nerve fibers of the anterior pituitary in rat after birth

研究大鼠出生后不同发育阶段 ,其脑下垂体前叶 P物质 ( substance P,SP)免疫反应阳性神经纤维的变化。 SD大鼠按其出生后年龄分为 5个实验组 :P1～ 2 ,P8,P1 5,P30 ,P45。采用免疫组织化学法观察大鼠垂体前叶 SP阳性神经纤维的发育变化。 P1～ 2期 ,大鼠垂体前叶中央分布有少量 SP阳性神经纤维 ,膨体呈长梭形。 P8期 ,阳性神经纤维可分为短粗类纤维和屈曲样膨体型纤维 ,前者主要分布于垂体前叶的浅表 ,后者主要分布于前叶的吻侧部及中央部 ,数量比 P1～ 2期多 ,且膨体较 P1～ 2期大 ,呈串珠状。P1 5期 ,阳性神经纤维分布较 P8期广泛 ,呈片状 ,短粗类纤维较 P8期长 ,屈曲样膨体型纤维分布于前叶中央。P30期 ,阳性神经纤维以屈曲样膨体型纤维为主 ,数量较 P1 5期增多。P45期 ,垂体前叶 SP纤维类型、分布同成年大鼠 ,其屈曲样膨体型纤维广泛分布于整个前叶。结果表明随出生后年龄的增长 ,大鼠垂体前叶 SP阳性纤维的类型、数量、分布逐渐由少到多 ,由分布于周边部到广泛分布于整个垂体前叶 ,呈现一种动态变化 ,说明出生后大鼠垂体前叶中 SP阳性纤维发育迅速。

To investigate the developmental changes of substance P(SP) immunoreactive (ir) nerve fibers of the anterior pituitary (AP) in rat during ontogeny, Sprague Dawley rats were divided into 5 groups according to their postnatal days:P1～2,P8,P15,P30,P45. Immunohistochemistry was applied. Sparse SP ir nerve fibers with spindle like varicosities of different sizes were distributed at the central part of the AP at P1～2. At P8 there were two kinds of SP ir nerve fibers: the short thick fiber and the tortuous varicose fiber. The former were localized at the superficial part of the AP and the latter were mainly distributed at the rostral and central parts of AP. The number of SP ir nerve fibers increased significantly compared to those of P1～2, strings of beads like varicosities were bigger than those of P1～2. At P15, patches of SP ir nerve fibers were distributed more widely than those of P8;the short thick fibers were longer than those of P8,the tortuous varicose fibers were distributed at central parts of AP. At P30,the number of tortuous varicose fibers increased significantly compared to those of P15. At P45, both the kinds and distribution of the nerve fibers were similar to those of the adult, the tortuous varicose fibers were diffusely distributed in AP. The results show that the kinds, number and distribution of SP ir nerve fibers of AP of the rat exhibit dynamic changes as the rat grows, and that the SP ir nerve fibers of AP in rat grow rapidly after birth. [