Effect of blockade of neuropeptide Y receptor on aortic intima-media thickness and adipose tissue characteristics in normal and obese mice

Atherosclerosis is an important risk factor for coronary heart disease. Neuropeptide Y (NPY) and its receptors, located in peripheral tissue such as white adipose tissue, have been linked to obesity and fat storage. The role of NPY in atherosclerosis has not yet been fully studied, so this study was conducted to further investigate the effect of BIIE 0246, an NPY receptor antagonist, on aortic intima-media thickness and size and number of adipocyte cells in normal and obese mice. Tests were performed on 24 male C57BL/6 mice. The animals were divided into four groups as follows: control (normal), obese (high-fat diet), normal+NPY receptor antagonist (1 μM, 100 µl/Kg BIIE0246 intraperitoneally) and obese+NPY receptor antagonist (n=6 each). After 14 days, the animals were sacrificed and epididymal adipose tissue and thoracic aorta were removed. Evaluations were made for adipocyte cell number and size and for aortic intima-media thickness. The group on a high-fat diet showed a significantly decreased number of adipocyte cells and increased cell size (P<0.05). BIIE0246 application changed the cell number of adipocyte in normal mice (P=0.05); however, it did not change adipocyte cell size and aortic intima-media thickness in obese and normal mice (P>0.05). NPY receptor antagonist had no effect on adipocyte cell size and aortic intima-media thickness; however, it decreased cell number in the normal group indicating likely involvement in the progression of obesity