Ultrastructure of Myocardial Cells in the Right Atrium of Spontaneous Hypertension Rats

  • Xueling Wei
Keywords: Spontaneous Hypertension, Myocardial Cells, Computer Aided Imaging, Ultrastructural Analysis

Abstract

Hypertension is the most common cardiovascular disease in China, which can seriously affect the heart, brain,
kidney and other vital organs of the human body, and is the main cause of cardiovascular and cerebrovascular
diseases and even death. Chronic hypertension can lead to remodeling of the right atrium, mainly due to factors
such as pressure and volume overload of the right atrium and overactivation of neuroendocrine factors. It mainly
includes cardiac remodeling and myocardial tissue remodeling. The purpose of this study was to observe the
ultrastructure of myocardial cells in the right atrium of spontaneous hypertension rats. In this study, 10
12-week-old SHR rats were selected as the experimental group (SHR group), and WKY rats of the same age and
sex were selected as the control group (WKY group, n = 10). Blood pressure was measured at the beginning and
end of the 18-week trial. A section of the rat right atrium was taken for staining, and the percentage of the
vascular wall area, the vascular lumen area (LA), and the vascular wall area of the heart wall were calculated by
using the computer-assisted imaging system. The results showed that WKY's blood pressure remained at the
normal level (106.65±6.55) mmHg. The blood pressure of SHR group increased from 8 weeks of age, and the
systolic blood pressure of SHR8, SHR16 and SHR24 groups were (121.4±5.60), (204.7±5.60) and (226.45±6.60)
mmHg, respectively, which were significantly higher than the WKY group of the same week (P < 0.05). In
30-week old SHR rats, the intima of the myocardial wall arterioles were significantly thickened and lumen
decreased. This mechanism may be related to the imbalance between proliferation and apoptosis of medium
smooth muscle cells. This paper introduces the characteristics of myocardial arteriole remodeling in SHR, which
provides a basis for the study of hypertension and its vascular remodeling as well as the prevention and
treatment of target organ damage.

Published
2020-06-01