Schröder H
Acta Anat (Basel). 1987;129(1):22-6.
Pineal melatonin synthetic activity shows distinct diurnal characteristics. The circadian regulation of melatonin synthesis is provided by noradrenaline-releasing sympathetic nerves. The pineal noradrenaline content shows a circadian rhythmicity tidally related to the changes in melatonin synthesis rate. To evaluate possible circadian changes of pineal noradrenergic fibre arrangement, the nerve distribution in rat and guinea pig pineal glands was visualized by means of glyoxylic acid-induced histofluorescence. Histochemical findings at 08.00 h and 24.00 h did not exhibit any differences: in both species a dense, mainly perivascularly located network of fluorescent fibres was encountered. As indicated by the simultaneous intraneural presence of green-bluish and yellow fluorophores these fibres most likely contain noradrenaline and serotonin. Obviously circadian melatonin synthesis changes are not paralleled by changes in the distribution pattern of pineal sympathetic nerve fibers. Like other sympathetic innervation-related morphological parameters, histofluorescence does not accurately reflect circadian biochemical changes in the pineal gland.
松果体褪黑素合成活性呈现出明显的昼夜特征。褪黑素合成的昼夜节律由释放去甲肾上腺素的交感神经提供。松果体去甲肾上腺素含量呈现出与褪黑素合成速率变化呈潮汐相关的昼夜节律。为了评估松果体去甲肾上腺素能纤维排列可能的昼夜变化，通过乙醛酸诱导的组织荧光观察大鼠和豚鼠松果体中的神经分布。在08:00和24:00的组织化学结果未显示任何差异：在这两个物种中，均遇到密集的、主要位于血管周围的荧光纤维网络。如神经内同时存在蓝绿色和黄色荧光团所示，这些纤维很可能含有去甲肾上腺素和5-羟色胺。显然，昼夜褪黑素合成变化与松果体交感神经纤维分布模式的变化并不平行。与其他交感神经支配相关的形态学参数一样，组织荧光不能准确反映松果体中的昼夜生化变化。
