Iloprost inhibits fracture repair in rats / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Previous studies have shown that prostaglandins (PGs) dramatically stimulate healing processes in bone. However, the effect of prostaglandin I2 (PGI2) on fracture healing remains unclear. To investigate the effect of PGI2, a study on fracture healing process in closed tibia fractures was designed.</p><p><b>METHODS</b>Thirty-six Sprague-Dawley male rats were randomized into two groups. On the first day, their right tibias were fractured by three-point bending technique. The study group (n = 18) received a single injection of 10 µg/kg iloprost for 5 days, while the control group (n = 18) received saline solution in the same way. On the 7th, 14th and 28th days following the fracture, six rats were sacrificed and their right legs were harvested in each group. The progression of fracture healing was assessed for each specimen by the scores of radiography (by Lane-Sandhu) and histology (by Huo et al).</p><p><b>RESULTS</b>On the 7th day, the radiographic and histologic scores were equal. On the 14th day radiographic total score was 6 and histologic total score was 23 in the iloprost group, whereas radiographic total score was 11 and histologic total score was 33 in the control group. On the 14th day radiographic and histologic scores were significantly decreased in the iloprost group compared to the control group (P < 0.05). On the 28th day radiographic total score was 12 and histologic total score was 37 in the iloprost group, whereas radiographic total score was 15 and histologic total score was 40 in the control group. On the 28th day although there was a decrease in radiographic and histologic scores of the iloprost group acording to control group, it was not statistically significant (P > 0.05).</p><p><b>CONCLUSION</b>Iloprost delays fracture healing in early stage in rats.</p>

Effect of perioperative feeding with fibre & arginine on morphometrics of ileum after surgical stress.

BACKGROUND & OBJECTIVE: Major surgeries as well as other types of injury have been shown to affect the gut function. Enteral diets influence intestinal mucosal morphometry to different extents depending on their composition. Little is known about the effects of these defined-formula diets in patients with surgical stress but no malnutrition. This experimental study was undertaken to compare the effects of different enteral diets on the mucosal morphometrics of small bowel in surgically stressed rats without malnutrition METHODS: Male Wistar-Albino rats (n=84) weighing between 160-220 g were randomised into three groups. Group A received standard rat chow. Group B received a complete balanced nutrition supplemented with fibre, and the rats in Group C were given an isocaloric specialized elemental nutrition enriched with specific combination of nutrients and arginine. The feeding was started two days before the operation and continued until re-operation. Laparotomy, ileal transection, and end-to-end anastomosis was performed as the surgical procedure. The rats were sacrificed on days 0, 2 and 7 post-operatively. One cm of ileal segment containing the anastomosis was examined histologically. Parameters for intestinal mucosal morphometry (number of villi, villous height, mucosal thickness) and number of mucous containing cells were determined. RESULTS: Number of mucous cells per villus was significantly (P<0.05) higher in group A compared to groups B and C on days 0 and 2 post-operation. On day 7 villous height and mucosal thickness were also significantly higher in group A compared to the other two groups. INTERPRETATION & CONCLUSION: Laparotomy and a minor surgical intervention such as small bowel transection was not a major surgical stress for intestinal mucosal atrophy in rats without malnutrition. The effect of fibre and arginine enriched defined-formula diets did not seem to improve intestinal mucosal changes in such a surgical stress model compared with normal rat chow.