Early stages of experimental atheromatosis.

In female Wistar rats, fed an atherogenic diet, the early changes of serum lipids and the deviation of the vasomotor response to adrenaline and acetylcholine were compared with morphological manifestations. It has been found that the first sign may be detected as the shift in serum lipoproteins and lipids just in a few days. Merging and decrease of alpha-lipoproteins and an increase of the beta-lipoprotein fraction proved as the most sensitive indicator. In the course of several weeks, an alteration of hemodynamic response to adrenaline and acetylcholine occured. The animals revealed a diminished depressoric response to acetylcholie, whereas their blood pressure response to adrenaline in the pressoric phase was decreased but the depressoric phase was markedly expressed. The morphological impairment of the vascular system followed with a delay of several months, although a lipoid infiltration of the liver appeared after 6 weeks of the atherogenic dietary regimen.