Hyperhomocysteinemia increases intimal hyperplasia in a rat carotid endarterectomy model

Serum homocysteine levels for homocysteine group (n = 8) and control group (n = 9; *P = .0007).

Amounts of intimal hyperplasia, expressed as percent stenosis, for homocysteine group (n = 8) and control group (n = 9; *P = .0007).

Photomicrograph of elastin-stained rat common carotid artery sections 2 weeks after CEA. Sections A1 and A2, from an animal in the control group, show significantly less neointimal hyperplasia than sections B1 and B2, from animals in the homocysteine group with elevated homocysteine levels. Magnification was ×10 (A1 and B1) and ×40 (A2 and B2). A2 and B2 are magnified sections of vessels seen in A1 and B1. Darker blue staining near the lumen is identified as area of IH. Note lack of internal elastic lamina in A2 and B2 and partial removal of external elastic lamina in B2. Remaining external elastic lamina is seen as thin black staining line.

Linear regression model of serum homocysteine levels and percent stenosis (y = 4.38 + 0.42x; df = 15; r² = 0.72; P = .0001).