Acta Anatomica Sinica ›› 2023, Vol. 54 ›› Issue (6): 716-721.doi: 10.16098/j.issn.0529-1356.2023.06.014

• Histology,Embryology and Developmental Biology • Previous Articles     Next Articles

Structural distribution and mechanism of elastic fibers and collagen fibers in ventricular interstitium of aged rats

XU Ya-ping YU Yue-xin CHEN Jin-fu2  WANG Ke-ke1  GUO Zhikun1,2*   

  1. 1.He’nan Provincial Key Laboratory of Heart Reconstruction and Transplantation, Zhengzhou Seventh Peoples Hospital, Zhengzhou 450000, China;  2.He’nan Provincial Key Laboratory of Tissue Regeneration, Xinxiang Medical University, Henan Xinxiang 453003, China

  • Received:2022-08-25 Revised:2023-02-01 Online:2023-12-06 Published:2023-12-06
  • Contact: GUO ZHIKUN E-mail:gzk@xxmu.edu.cn

Abstract:

Objective  To investigate the structural distribution features and mechanism of elastic fibers and collagen fibers in ventricular interstitium of aged rats.  Methods Five young SD rats (24 weeks) and five old SD rats (104 weeks) were used,and their cardiac function was examined by echocardiography. Modified Weigert elastic fiber staining, immunohistochemistry, immunofluorescence and Western blotting techniques were used to detect the expression changes of type I and Ⅲ collagen fibers and their proteins, elastic fibers and their proteins, matrix metalloproteinase 2 (MMP-2), matrix metalloproteinase 9 (MMP-9) and tissue inhibitor of metalloproteinase 2 (TIMP-2), respectively.    Results The type I and type Ⅲ collagen in the ventricular interstitium of aged rats was very sufficient and wrapped around the cardiomyocytes. Compared with the young rats, the content of collagen protein in the ventricular interstitium of the aged rats significantly increased (P<0.05). Elastic fibers in the ventricular interstitium of the aged rats were and widely distributed. Compared with the young rats, the number of elastic fibers and the level of elastin in the ventricular interstitium of the aged rats significantly decreased (P<0.05), and the expression levels of MMP-2 and MMP-9 in ventricular muscle of aged rats increased, and they were correlated with the level of elastin. The level of TIMP-2 in ventricular muscle of aged rats decreased with age.   Conclusion The number of collagen fibers and elastic fibers in ventricular interstitium of aged rats is fluctuated with each other. With the increase of age, the contents of TIMP-2 and elastic fibers in the ventricular interstitium gradually decreased, and the ratio of collagen fibers to elastic fibers is out of balance.

Key words: Matrix metalloproteinase 2, Matrix metalloproteinase 9, Tissue inhibitor of metalloproteinase 2, Collagen fiber, Elastic fiber, Ventricular muscle, Immunofluorescence, Western blotting, Rat

CLC Number: