Résumé
Background: Information of the three dimensional (3D) structure of vascular smooth muscle cells (VSMCs) is essential for understanding the regulatory mechanism of blood flow in the microvascular system. objective: To examine the 3D structure of individual VSMCs in rabbit mesenteric arterioles, using confocal laser scanning microscopy. Methods: Japanese white rabbits were anesthetized with urethane and α-chlorase. After intravital observation of the mesenteric microcirculation under a videomicroscope, the intestine with mesentery was extracted and perfused and fixed with paraformaldehyde under a static pressure (100 mmHg). A section of the mesentery was isolated from the intestine and spread out to simulate the in vivo geometry of the the vascular network. The mesenteric section was stained with fluorescein anti-smooth muscle myosin antibody and rhodamine-labeled anti-rabbit Ig antibody. The samples were observed using confocal laser microscopy, and the 3D images were reconstructed by means of sliced images. The cross-sectional image was re-sliced to measure two axes of the best-fitting ellipse. Single VSMCs were picked out from the vascular wall using the continuity law of density distribution of vessel wall. Results: The cross-sectional shapes of arterioles were not circular but elliptical. The aspect ratio (major to minor axis) of the best-fitting ellipse was in the range from 0.3 to 0.7 for 28 arterioles (diameters: 10-30 μm). On the 3D image of VSMCs, the cell width ranged from 2.2 to 4.5 μm. The cells were classified into round and spindle types. The cell width of round shape was significantly larger than that of spindle shape. The VSMCs appeared to arrange circumferentially and tightly along the cross-section along the axis of vessel. The mean length of single VSMCs was approximately 1.2 times of the circumferential length of the arteriole. This cellular arrangement may have influence on the distribution of mechanical stress by VSMC-induced myogenic force. Conclusion: Confocal laser microscopy is useful for quantitative analysis of the 3D arrangement of individual VSHCs. Keywords: Arteriole, cellular arrangement, confocal laser microscopy, cross-sectional shape, mesentery, vascular smooth muscle cell.
Résumé
The effects of Red Ginseng on osteopenia were investigated in ovariectomized rats. Eight-week-old female Wistar rats were used. Sham operating and ovariectomized control (OVX Cont) rats were given the vehicle. Korean Red Ginseng extract powder (0.1g/kg/day p. o.) was administered to another ovariectomized group (OVX RG). After 12 weeks, blood was drawn, and jejunum and tibia were removed. Histologial parameters in bone and intestinal villi were measured. Biochemical and endocrinological parameters were also measured. Although ovariectomy significantly increased body weight of rats, there was no significant difference between OVX Cont and OVX RG in body weight gain. Bone volume in OVX Cont was significantly lower than in sham operating rats. Administration of Red Ginseng significantly increased the bone volume of tibia in ovariectomized rats. Intestinal villous height in OVX Cont was significantly lower than in sham operating rats. There was a tendency towards increasing intestinal villous height in OVX RG. Administration of Red Ginseng significantly decreased the frequencies of abnormally shaped villi in ovariectomized rats. This experimental study showed that Red Ginseng was effective in inhibiting osteopenia in ovariectomized rats, and it appears that the effect on bone is related to that on intestinal villi.
Résumé
The effects of Rikkunshi-to (Liu jun zi tang), Hochu-ekki-to (Bu zhong yi qi tang), and Hange-shashin-to (Ban xia xie xin tang) on morphological changes in the small intestinal mucosa of mice with age were observed. The results indicated that Rikkunshi-to and Hochu-ekki-to had a beneficial effect on intestinal mucosal changes in 36-weeks-old mice. In particular, the improvement of the absorptive area of the intestinal villi and microvilli depending on the concentration of medicine was found. Ninjin-yoei-to had a strong effect on aged mice of 50 and 70 weeks. The morphology and absorptive function were significantly improved.