Turto H
Cardiovasc Res. 1977 Jul;11(4):358-66. doi: 10.1093/cvr/11.4.358.
It is generally agreed that cardiac hypertrophy is accompanied by the hyperplasia of connective tissue cells. In the present work, collagen metabolism was studied in the heart of nondigitalised and digitalised rats after the constriction of the aorta. The activity of prolyl hydroxylase was maximally increased 2 days after the operation. The incorporation of proline into collagen hydroxyproline increased without any increase in the specific radioactivity of free intracellular proline, the peak labelling of collagen occurring at 4 days. Although the treatment of the rats with digitoxin prevented the development of cardiac hypertrophy and an increase in collagen labelling, an increase in the activity of prolyl hydroxylase was observed. The intracellular free proline pool and its specific radioactivity were significantly lower in digitalised rats as compared with non-digitalised rats. The results indicate that constriction of the aorta is accompanied by an activation of connective tissue cells leading to increased synthesis of collagen. However, digitoxin treatment can prevent the increase in collagen labelling, possibly by inhibiting the amino acid transport, but it is unable to remove the stimulus for hypertrophy.
人们普遍认为心脏肥大伴随着结缔组织细胞的增生。在本研究中，对主动脉缩窄后的未用洋地黄和已用洋地黄大鼠的心脏中的胶原代谢进行了研究。脯氨酰羟化酶的活性在手术后2天最大程度地增加。脯氨酸掺入胶原羟脯氨酸增加，而细胞内游离脯氨酸的比放射性没有任何增加，胶原的峰值标记出现在4天。尽管用洋地黄毒苷处理大鼠可防止心脏肥大的发展和胶原标记的增加，但仍观察到脯氨酰羟化酶活性增加。与未用洋地黄的大鼠相比，已用洋地黄的大鼠细胞内游离脯氨酸池及其比放射性明显更低。结果表明，主动脉缩窄伴随着结缔组织细胞的激活，导致胶原合成增加。然而，洋地黄毒苷处理可能通过抑制氨基酸转运来防止胶原标记增加，但它无法消除肥大的刺激因素。
