Novel atherosclerotic lesions were induced in the Microminipig (
MMP, registered with the Japanese Ministry of Agriculture, Forestry and Fisheries as a novel variety of swine), the smallest pig available for experimental use, by feeding a high fat (12%) and high
cholesterol (5%) diet (HFCD) with
sodium cholate (SC, 0.7%) (HFCD/SC) for three months. Three
MMPs were used: a male fed with normal diet (M-ND), and a male and an ovariectomized female fed with HFCD/SC (M-HFCD/SC and Fx-HFCD/SC). HFCD/SC induced
hypercholesterolemia accompanied by an increase in serum total
cholesterol (T-Cho),
low-density lipoprotein cholesterol (
LDL-C),
high-density lipoprotein cholesterol (HDL-C) and
cholesterol ester (CE) from the first week. Serum levels of T-Cho,
LDL-C and CE reached a maximum in two to three weeks, and HDL-C gradually increased during the experimental period (duration). Serum
lipoprotein analysis showed a dominant
LDL-C fraction, as seen in humans, in all three
MMPs.
Body weight gain in the
MMPs fed with HFCD/SC was greater than in the animal fed with M-ND. At the end of the experiment, computed tomography scans of conscious animals showed increases in subcutaneous and abdominal fat in those fed with HFCD/SC, suggesting the induction of
obesity. Atherosclerotic lesions in systemic arteries (including external and internal iliac arteries, abdominal aorta, coronary artery, cerebral arterial circle), fatty changes, and foamy cell infiltration in the liver and spleen were histopathologically observed in the
MMPs fed with HFCD/SC.
Atherosclerosis and the pathological findings induced by HFCD/SC in
MMPs were similar to the pathological changes associated with human
atherosclerosis, suggesting that the
MMP has the potential to be a suitable animal model for human
atherosclerosis.