Needler M C, Wilkinson M, Prusky G, Shaw C, Cynader M
Department of Physiology and Biophysics, Dalhousie University, Halifax, Canada.
Brain Res. 1988 Aug 1;470(2):217-27. doi: 10.1016/0165-3806(88)90240-4.
Tritiated phorbol-12,13-dibutyrate [( 3H]PDBu), a phorbol ester, was utilized to autoradiographically localize protein kinase C (PKC) in the cat visual cortex. Thin, slide-mounted sections of adult cat brain were used to characterize binding of [3H]PDBu. This was found to be saturable, reversible, and more readily displaced by phorbol ester than by synthetic diacylglycerols. Binding sites displayed a tissue concentration of 20 pmol/mg protein, and a dissociation constant of 8.0 nM. [3H]PDBu was slow to associate with its receptor, requiring 9.5 h to reach equilibrium. Autoradiograph revealed that PKC is heterogeneously distributed in the cat brain, and displays a laminar-specific pattern in the visual cortex. This laminar distribution undergoes marked changes during the first two months of postnatal life. In the visual cortex of neonatal kittens, [3H]PDBu binding is confined to layers I and V. Layer III acquires high levels of binding by postnatal day 15, layer II by 28 days, and layer VI becomes labelled by 40 days of age. Adult animals exhibit high levels of binding in all laminae except layer IV. Age-dependent changes in PKC's laminar distribution do not seem to be correlated with specific anatomical, neurochemical, or behavioural events during development. PKC appears to be associated with cell bodies or processes intrinsic to the visual cortex, and is probably not located on the terminals of cortical afferents.
氚标记的佛波醇-12,13-二丁酸酯[（³H）PDBu]，一种佛波酯，被用于通过放射自显影法在猫的视觉皮层中定位蛋白激酶C（PKC）。使用成年猫脑的薄切片并将其安装在载玻片上来表征[³H]PDBu的结合情况。发现这种结合是可饱和的、可逆的，并且与合成二酰基甘油相比，更容易被佛波酯取代。结合位点的组织浓度为20 pmol/mg蛋白质，解离常数为8.0 nM。[³H]PDBu与其受体结合缓慢，达到平衡需要9.5小时。放射自显影显示PKC在猫脑中呈异质性分布，并且在视觉皮层中呈现出层特异性模式。这种层状分布在出生后的头两个月会发生显著变化。在新生小猫的视觉皮层中，[³H]PDBu结合局限于I层和V层。到出生后第15天，III层获得高水平的结合，到28天时II层获得结合，VI层在40日龄时被标记。成年动物除IV层外的所有层中都表现出高水平的结合。PKC层状分布的年龄依赖性变化似乎与发育过程中的特定解剖学、神经化学或行为事件无关。PKC似乎与视觉皮层固有的细胞体或突起相关，并且可能不在皮质传入纤维的终末上。
