Effects of Different Lipid Diets on Myocardial Extracellular Matrix-Related Gene Expression in Healthy Rats

The myocardial extracellular matrix (ECM) is essential for cardiac architecture, ventricular compliance, and cell-matrix signaling. Because dietary lipid quality can influence oxidative stress, inflammation, and cardiometabolic regulation, it may also affect myocardial ECM homeostasis. This exploratory study assessed whether different lipid-enriched diets modified myocardial ECM-related transcript expression in healthy rats. Forty rats were allocated to five groups (n = 8 per group) and received for 12 weeks either a control diet or diets enriched with crude palm oil, refined palm oil, olive oil, or lard. Myocardial tissue was collected at sacrifice, RNA was extracted and reverse-transcribed into complementary DNA, and relative expression of elastin, vimentin, myonectin, matrix metalloproteinase-2 (MMP-2), and the apelin receptor (APJ) was assessed by polymerase chain reaction using ribosomal protein lateral stalk subunit P0 (Rplp0) as the reference gene. Results were expressed as mean ± standard deviation and analyzed by analysis of variance followed by Tukey-Kramer multiple comparisons, with p < 0.05 considered statistically significant. No statistically significant between-group differences were observed for elastin, vimentin, MMP-2, myonectin, or APJ expression (all p > 0.05), although slight non-significant qualitative fluctuations were observed for myonectin and APJ in some lipid-fed groups. Overall, the findings indicate that under the specific conditions of this 12-week experiment in healthy rats, the tested dietary lipids did not measurably disrupt myocardial ECM-related gene expression. Because the study was limited to transcript-level assessment and did not include protein, histological, or functional validation, the biological interpretation should remain restricted to early molecular observations under non-pathological conditions.