AJP - Regulatory, Integrative and Comparative Physiology, Vol 258, Issue 4 1042-R1050, Copyright © 1990 by American Physiological Society
Association of DOCA hypertension with induction of atherosclerosis in rats with short-term diabetes mellitus
R. A. Hebden, M. E. Todd, C. Tang, B. Gowen and J. H. McNeill
Division of Pharmacology and Toxicology, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada.
We investigated the effect of deoxycorticosterone acetate (DOCA)-induced
hypertension on plasma lipid and cholesterol levels and the development of
vascular atherosclerotic changes in male Wistar rats injected with
streptozotocin (STZ) or saline (CON). Rats given STZ alone demonstrated a
mild hyperlipidemia and hypercholesterolemia without any change in blood
pressure. One week of DOCA administration was without effect on blood
pressure in CON and STZ groups, but at 3 and 6 wk caused a significant and
similar elevation in both groups. This DOCA-induced elevation in blood
pressure appeared to be associated with the increase in plasma lipid and
cholesterol levels seen in both CON and STZ groups at 3 and 6 wk, although
the elevation in lipid and cholesterol levels was significantly more
pronounced in the STZ rats. Both CON and STZ groups injected with DOCA
developed significant pathological changes in all vessels under
investigation. However, the degree of atherosclerosis appeared, from a
semiquantitative analysis, to be worse in the thoracic aortas and renal
arteries of the STZ group. Neither normotensive group developed any
atherosclerosis. It is concluded that hypertension is associated with
atherosclerosis in normal rats and rats with short-term STZ-induced
diabetes mellitus, although the higher plasma lipid and cholesterol levels
of the latter group may potentiate the degree of vascular damage.
