The combination of high dietary methionine plus cholesterol induces myocardial fibrosis in rabbits.
Limited evidence suggests that myocardial fibrosis might be associated with dietary cardiovascular risk factors.


OBJECTIVE
To investigate the effects of high dietary cholesterol, methionine (the precursor to homocysteine), and the combination of the two diets on myocardial fibrosis.


METHODS
Rabbits were randomly allocated into four dietary groups for 12 weeks: control (Con), 1% methionine (Meth), 0.5% cholesterol (Chol) or 1% methionine plus 0.5% cholesterol (MethChol).


RESULTS
Myocardial fibrosis was not significantly increased in Chol or Meth. However, interstitial fibrosis increased by 85% (p = 0.03) and perivascular fibrosis 28-fold (p < 0.01) in the MethChol group compared to Con.


CONCLUSIONS
These results suggest that high levels of dietary cholesterol or methionine alone do not significantly increase myocardial collagen content. However, the combination of the two diets does cause myocardial fibrosis. Therefore, excessive cholesterol and methionine intake may be an important pathogenic factor in the development of myocardial fibrosis.
Zulli
Anthony
A
Vascular Laboratory, Department of Cardiology, University of Melbourne, Austin Health, Heidelberg, Australia. azulli@unimelb.edu.au
Hare
David L
DL
Buxton
Brian F
BF
Black
M Jane
MJ
D000818:Animals; D002791:Cholesterol, Dietary / Q000009:adverse effects*; D003094:Collagen / Q000378:metabolism; D003331:Coronary Vessels / Q000378:metabolism / Q000473:pathology; D005355:Fibrosis; D008297:Male; D008715:Methionine / Q000008:administration & dosage / Q000009:adverse effects*; D009206:Myocardium / Q000473:pathology*; D011817:Rabbits
D002791:Cholesterol, Dietary; D003094:Collagen; D008715:Methionine