In utero undernutrition in rats induces increased vascular smooth muscle content in the offspring

Objective

We hypothesized that undernutrition in utero alters the structure of conduit and resistance vessels early in development.

Study Design

We studied a rodent model in which dams were 50% food restricted from day 10 of gestation to term. Vascular smooth muscle content and vascular caliber in the offspring were examined by quantitative histologic methods and by Western blot analysis.

Results

Maternal food restriction induced a significant increase in the smooth muscle content of 1-day- and 2-month-old offspring aortas and mesenteric arterioles of different luminal diameters. Histologic data were confirmed by Western blot analysis that showed greater expression of smooth muscle α-actin in 1-day-old food restriction aortas. The increase in vascular smooth muscle in the aortas was determined to be the result of cellular hypertrophy.

Conclusion

These results demonstrate that the vascular smooth muscle is altered in food-restriction offspring and that this may be a mechanism for the programming of offspring hypertension.

Key words: in utero undernutrition, programming, smooth muscle α-actin, vascular smooth muscle