Figure 1 5-fluorouracil and bevacizumab reduced heart weight and
increased ST offset and PR interval. (n=8) A: Electrocardiogram showed
small differences between control group and 5-fluorouracil + bevacizumab
group. B: 5-fluorouracil + bevacizumab caused a small reduction in
average heart rate. C: Q wave amplitude reduced on the 14th day after
injection. D: No obvious changes in T wave amplitude were seen. E: No
obvious changes in QRS interval were seen. F: ST offset increased in
5-fluorouracil + bevacizumab group on the 7th and 14th day after
injection. G: PR interval increased in 5-fluorouracil + bevacizumab
group on the 7th and 14th day after injection. H: No obvious changes in
QT interval were seen. I: the body weight slightly reduced on the 7th
and 14th day after injection. J: the heart weight index obviously
reduced on the 7th and 14th day after injection. 5-FU + BEV group:
5-fluorouracil + bevacizumab group.
The myocardial uptake
increased on the 7th day and decreased on the 14th day on PET-CT : In
clinic, 18F-FDG was used to detect myocardial
metabolism and survival. Therefore, PET-CT was performed to the mice in
each group on the 7th and 14th day after injection. On the 7th day after
injection, the myocardial uptake of 5-fluorouracil + bevacizumab group
was significantly higher than that of the control group, and the cardiac
uptake was diffusely increased, but the corresponding CT scan showed no
significant changes in cardiac structure. On the 14th day after
injection, the 18F-FDG myocardial uptake in the
5-fluorouracil + bevacizumab group was lower than that in the control
group, and lower than that on the 7th day, even some of the ventricular
walls were filling defect. And the defect walls were mainly the left
ventricle inferior wallăposterior wall and posterior interval. At the
same time, the corresponding CT scan showed no significant changes in
the heart structure between the two groups. It can be seen that PET can
detect cardiotoxicity caused by antineoplastic drugs in the early stage,
and the increase of myocardial metabolism in the chemotherapy induced
cardiotoxicity may be one of the early manifestations. As figure 3, part
A.
No obvious changes in B-type natriuretic peptide concentration
were seen: BNP (B-type natriuretic peptide) was a natural hormone with
biological activity synthesized by cardiomyocytes, which was mainly
expressed in ventricles and also existed in brain tissue. As a
quantitative marker of heart failure, BNP not only reflects left
ventricular systolic dysfunction, which also reflects left ventricular
diastolic dysfunction, valve dysfunction and right ventricular
dysfunction. Therefore, we measured the BNP content in serum of mice in
each group. Compared with the control group, BNP in the serum of
5-fluorouracil + bevacizumab group on the 7th and 14th day did not
change significantly (P >0.05), even in the serum of
5-fluorouracil + bevacizumab group on the 14th day was slightly lower
than that on the 7th day. As figure 3, part B.
Revealed myofibril irregular on the 14th day: After 7 and 14
days of injection of 5-fluorouracil and bevacizumab, the hearts of mice
were washed and weighed. After HE
staining of myocardial sections, it was observed that some of the
myofibril arranged irregularly in
a small range after 5-fluorouracil and bevacizumab were given. As figure
3, part C.