Levin B E, Dunn-Meynell A
Neurology Service, Veterans Administration Medical Center, E. Orange, NJ 07019.
Brain Res. 1989 Aug 14;494(2):325-38. doi: 10.1016/0006-8993(89)90601-x.
Fetal (E15-16) somatosensory cortex (n = 15) or cerebellum (n = 9) were placed into the somatosensory cortex (SmI) of adult rat hosts to study the relative importance of tissue origin versus host milieu on graft beta-adrenoceptor regulation. Autoradiographic studies of [125I]pindolol ([125I]pin) binding in the presence of 3 microM serotonin were performed as an index of beta-receptor binding in both intact hosts and those with ipsilateral locus coeruleus (LC) lesions and/or ipsilateral superior cervical ganglionectomy. [125I]pin binding within fetal grafts was highly variable with areas of highest specific binding in cortical grafts (Kd = 209 +/- 30 pM, Bmax = 106 +/- 7 (fmol/mg protein) being comparable to host cortex (Kd = 211 +/- 41 pM, Bmax = 111 +/- 9 fmol/mg protein). Average total binding in whole cortical grafts was 73% and in cerebellar grafts was 60% of that in comparable adult cortex. Host cortex had 66-73% and cerebellum had 4-8% beta 1-receptors while cortical grafts had 59% and cerebellar grafts had 43% beta 1-receptors as determined by competitive binding with ICI 89406 and 118551. Noradrenergic fibers derived from both the host LC and superior cervical ganglion grew into fetal cortical grafts. Binding to high affinity uptake sites ([3H]desmethylimipramine, [3H]DMI) on noradrenergic terminals in cerebellar grafts was 28% higher than that in cortical grafts; superior cervical ganglionectomy decreased [3H]DMI binding in cortical grafts by 37% but had no effect on cerebellar grafts. Neither ganglionectomy nor LC lesions affected total specific binding or binding to beta-receptor subtypes in the grafts or host cortex 3-6 months after removal. Therefore, anatomic site of origin appeared to be the predominant factor in determining the development of beta-adrenoceptors in fetal cortical tissue. In ectopically placed cerebellar grafts, beta-receptor subtypes did not develop comparably to host cerebellar receptors suggesting that host milieu may be of critical importance in receptor development in this tissue.
将胎龄（E15 - 16）的体感皮层（n = 15）或小脑（n = 9）植入成年大鼠宿主的体感皮层（SmI），以研究组织来源与宿主环境对移植体β - 肾上腺素能受体调节的相对重要性。在3 microM血清素存在的情况下，进行了[125I]哌哚洛尔（[125I]pin）结合的放射自显影研究，以此作为完整宿主以及同侧蓝斑（LC）损伤和/或同侧颈上神经节切除宿主中β受体结合的指标。胎儿移植体内的[125I]pin结合高度可变，皮质移植体中特异性结合最高的区域（Kd = 209 +/- 30 pM，Bmax = 106 +/- 7（fmol/mg蛋白））与宿主皮层相当（Kd = 211 +/- 41 pM，Bmax = 111 +/- 9 fmol/mg蛋白）。整个皮质移植体的平均总结合量为成年对照皮层的73%，小脑移植体为60%。通过与ICI 89406和118551竞争结合测定，宿主皮层有66 - 73%的β1受体，小脑有4 - 8%的β1受体，而皮质移植体有59%的β1受体，小脑移植体有43%的β1受体。源自宿主LC和颈上神经节的去甲肾上腺素能纤维长入胎儿皮质移植体。小脑移植体中去甲肾上腺素能终末上高亲和力摄取位点（[3H]去甲丙咪嗪，[3H]DMI）的结合比皮质移植体高28%；颈上神经节切除使皮质移植体中的[3H]DMI结合降低37%，但对小脑移植体无影响。在切除后3 - 6个月，神经节切除和LC损伤均未影响移植体或宿主皮层中的总特异性结合或与β受体亚型的结合。因此，起源的解剖部位似乎是决定胎儿皮质组织中β - 肾上腺素能受体发育的主要因素。在异位植入的小脑移植体中，β受体亚型的发育与宿主小脑受体不同，这表明宿主环境在该组织的受体发育中可能至关重要。 }
