Arterial wall and smooth muscle cell development in young Wistar rats and the effects of surgical denervation.

Abstract

Development of the muscular saphenous artery and the effect of surgical denervation on normal development was investigated in young rats at 3 and 6 weeks of age. During this interval, the weight and blood pressures (systolic, diastolic, and mean) of the animals increased significantly. The tunica media of the artery and the lumen increased significantly with age, but the proportion of smooth muscle cell to paracellular matrix did not alter. Computer-assisted three-dimensional reconstructions were used to investigate the smooth muscle cells. They increased significantly in length, volume, and angle of orientation within the vessel wall with age but maintained an approximate surface area-to-volume ratio. The cells in any one vessel tended to be oriented in either a clockwise or counterclockwise direction. The size of the nucleus also increased significantly in length and volume with age, but an approximate surface area-to-volume ratio and a constant nucleocytoplasmic ratio were maintained. The nuclei tended to be eccentrically located, with less than half of all nuclei wholly within the middle third of the cell. Surgical denervation at 10 days of age resulted in abnormalities of growth in vessel dimensions, thinner tunica media at 3 weeks (denervated 11 days previously), and smaller lumen at 6 weeks (denervated 32 days previously). Elevated amounts of paracellular matrix occurred in both age groups, but denervation did not alter smooth muscle cell size. In the 3-week-old animals, denervation resulted in smooth muscle cells with hypertrophied nuclei. This may account for the increase in growth of the tunica media between 3 and 6 weeks of age in the denervated artery.(ABSTRACT TRUNCATED AT 250 WORDS)

Relaxation by vasoactive intestinal polypeptide in the gastric fundus of nitric oxide synthase‐deficient mice

“…9.4 ± 0.2 weeks for Sv129, n = 18, and 6.8 ± 0.6 weeks for eNOS(−/−), n = 18). This age‐related difference in cell length was also observed in smooth muscle cells of the rat muscular saphenous artery (Todd et al 1991). The length of the isolated smooth muscle cells from nNOS(−/−) mice was not different from that in the WT B6.129F2/J mice, as their age was similar (8.8 ± 0.7 weeks for B6.129F2/J, n = 6, 8.2 ± 0.7 weeks for nNOS(−/−), n = 5).…”

Paracrine control of vascular innervation in health and disease

“…1993). Furthermore, sympathetic denervation of arteries results in reduced SMC proliferation and differentiation and reduced medial cross‐sectional area (Bevan 1975, Bevan & Tsuru 1981, Todd & Gowen 1991). Consistent herewith, sympathectomy resulted in increased vimentin expression in several arteries in the rat, indicative of vascular SMC dedifferentiation (Kacem et al.…”

Role of the Sympathetic Autonomic Nervous System in Hypoxic Remodeling of the Fetal Cerebral Vasculature

“…Sympathetic nerves can also exert potent long-term trophic effects on arterial structure and function (78, 83–85). Some of these changes include increases in arterial wall stiffness secondary to either surgical or chemical sympathectomy in multiple models (86, 87) suggesting that sympathetic nerves mediate preferential decreases in the ratio of collagen to elastin (88).…”