Modulation of tyrosine hydroxylase gene expression in the rat adrenal gland by age and reserpine.
Modulation of tyrosine hydroxylase gene expression in the rat adrenal gland by age and reserpine.
复制标题
年龄和利血平对大鼠肾上腺酪氨酸羟化酶基因表达的调节。
DOI：
10.1016/0006-8993(90)91327-d
复制
发表时间：
1990
期刊：
影响因子：
2.9
通讯作者：
Richardson,A
中科院分区：
文献类型：
--
作者：
Strong,R;Moore,MA;Hale,C;Wessels-Reiker,M;Armbrecht,HJ;Richardson,A
同时测定了2、6、13和23个月龄Fischer 344大鼠肾上腺中的酪氨酸羟化酶（TH）、TH信使RNA（TH mRNA）和多巴胺（DA）。在2至23个月之间，TH活性上升2倍，与最年轻的组相比。肾上腺TH mRNA含量在2 ~ 23个月间增加3倍。肾上腺DA含量增加3倍，TH的第一个儿茶酚胺产物，提供了TH基因表达增加的证据，在功能上是显着的。为了确定调节基因表达的机制是否会因衰老而改变，在另一组年龄为2、12和27个月的大鼠中比较了利血平对TH mRNA和TH活性诱导的影响。与第一个实验的结果相一致，在年龄匹配的对照组中，TH活性和TH mRNA都有与年龄相关的增加。TH活性上升2倍，TH mRNA上升超过6倍之间的2和27个月。TH mRNA和TH蛋白增加的相对幅度的差异表明TH mRNA和TH蛋白水平调节的解偶联。此外，有显着的年龄相关的差异与利血平治疗的TH基因表达的调制。利血平能诱导幼鼠TH活性，但不能诱导两个老龄组TH活性。相反，利血平引起显着的诱导TH mRNA在所有年龄组。这些结果提供的证据表明，衰老是伴随着改变的转录和转录后机制参与调节TH基因的表达。
Tyrosine hydroxylase (TH), TH messenger RNA (TH mRNA) and dopamine (DA) were measured simultaneously in adrenal glands of individual Fischer 344 rats aged 2, 6, 13 and 23 months. Between 2 and 23 months TH activity rose 2-fold as compared to the youngest group. TH mRNA content of the adrenal gland rose 3-fold between 2 and 23 months. A 3-fold increase in adrenal DA content, the first catecholamine product of TH, provides evidence that the increases in TH gene expression are functionally significant. To determine if mechanisms that regulate gene expression are altered by aging, the effects of reserpine on induction of TH mRNA and TH activity were compared in another group of rats aged 2, 12 and 27 months. Consistent with the results of the first experiment, there were age-related increases in both TH activity and TH mRNA in the age-matched control groups. TH activity rose 2-fold and TH mRNA rose more than 6-fold between 2 and 27 months. The discrepancy in the relative magnitudes of increases in TH mRNA and TH protein suggest an uncoupling of regulation of TH mRNA and TH protein levels. Moreover, there were significant age-related differences with respect to modulation of TH gene expression by reserpine treatment. TH activity was induced by reserpine in the youngest group, but not in the two older age-groups. In contrast, reserpine caused significant induction of TH mRNA in all age groups. These results provide evidence that aging is accompanied by alterations in transcriptional and post-transcriptional mechanisms involved in regulation of TH gene expression.