Blay P, Nilsson C, Hansson S, Owman C, Aldred A R, Schreiber G
Department of Medical Cell Research, University of Lund, Sweden.
Brain Res. 1994 Oct 31;662(1-2):148-54. doi: 10.1016/0006-8993(94)90807-9.
Brain expression of transferrin (Tf) and transthyretin (TTR) mRNA has been demonstrated in different species, TTR being found only in the choroid plexus. We report here that both these mRNAs are also expressed in the meninges. In vitro studies have shown that Tf secretion by the rat choroid plexus is stimulated by 5-hydroxytryptamine (5-HT) while sympathetic nerves regulate different transport functions in the same tissue. We have used various in vivo models to study the neuroendocrine regulation of Tf and TTR mRNA expression in the choroid plexus and meninges. Destruction of the serotonergic nerves in the brain by either raphe nuclei lesion or intraventricular injections of 5,7-dihydroxytryptamine (5,7-DHT), which both decreased brain 5-HT levels significantly, did not affect Tf or TTR mRNA levels in choroid plexus and meninges, but increased TTR mRNA in liver. Intraventricular injection of 10 or 100 pmol 5-HT did not change the expression of these proteins in any of the tissues studied. Removal of the sympathetic innervation to the choroid plexus by cervical sympathectomy did not affect Tf or TTR mRNA levels in choroid plexus and liver, nor the incorporation of radioactive leucine into protein in various parts of the brain. In conclusion, our results do not support a regulatory role in vivo for neuronally derived 5-HT or sympathetic nerve activity on Tf and TTR mRNA expression in rat choroid plexus and meninges.
转铁蛋白（Tf）和甲状腺素转运蛋白（TTR）mRNA在不同物种的大脑中均有表达，而TTR仅在脉络丛中被发现。我们在此报告，这两种mRNA在脑膜中也有表达。体外研究表明，大鼠脉络丛分泌Tf受5-羟色胺（5-HT）刺激，而交感神经调节同一组织中的不同转运功能。我们使用了各种体内模型来研究脉络丛和脑膜中Tf和TTR mRNA表达的神经内分泌调节。通过中缝核损伤或脑室内注射5,7-二羟色胺（5,7-DHT）破坏大脑中的5-羟色胺能神经，二者均显著降低了大脑5-HT水平，但并未影响脉络丛和脑膜中Tf或TTR mRNA水平，却增加了肝脏中TTR mRNA水平。脑室内注射10或100 pmol 5-HT并未改变所研究的任何组织中这些蛋白质的表达。通过颈交感神经切除术去除脉络丛的交感神经支配，并未影响脉络丛和肝脏中Tf或TTR mRNA水平，也未影响放射性亮氨酸在大脑各部位掺入蛋白质的情况。总之，我们的结果不支持神经元源性5-HT或交感神经活动在体内对大鼠脉络丛和脑膜中Tf和TTR mRNA表达起调节作用。
