Highly reproducible skeletal deformities induced by administration of β-aminopropionitrile to developing chick embryos

BAPN-induced rodent model of aortic dissecting aneurysm and related complications

Background

The aim of this study was to investigate the effects of beta-aminopropionitrile (BAPN) on the arterial walls of rodents, and to analyze the gross or pathological changes of arterial and other tissues of rodents treated with BAPN at different concentrations or doses.

Methods

Eighteen SPF SD rats (4–5-week old) were divided into three groups: SD-0.2 (Group A), SD-0.4 (Group B), and SD-0.6 (Group C). The groups A, B and C were given 0.2%, 0.4%, and 0.6% BAPN solution, respectively, as drinking water for seven weeks. Forty SPF C57BL/6 mice (3-week old) were randomly divided into four groups: C57-0.2 (Group D), C57-0.4 (Group E), C57-0.6 (Group F) and the control group and given 0.2%, 0.4%, or 0.6% BAPN or distilled water as drinking water, respectively, for seven weeks. All experimental animals were free to drink water. The aortas were dissected and visually examined. At the same time, hematoxylin and eosin (HE) staining was performed in aorta tissue. The vascular diameter and area of the middle membrane were measured with IPP (Image-Pro Plus 6.0).

Results

BAPN treatment significantly affected the water intake and weight gain of rats and mice. BAPN also caused thickening of the membrane in the aortas of rats and mice, and irregularity in the arrangement of elastic fibers. These pathological changes are similar to the pathological changes observed in human aneurysms. The incidence of dissecting aneurysm in C57 mice was higher than that of Sprague Dawley (SD) rats.

Conclusions

BAPN at a concentration of 0.4% was feasible to produce an animal model of dissecting aneurysm. In SD rats, the rate of pathological changes and other complications, such as intestinal rupture and scoliosis, was higher than the rates of dissecting aneurysm.

Effect of Collagen Cross-Link Deficiency on Incorporation of Grafted Bone

Bone matrix collagen, is one of the major contributors to bone quality. No studies have examined how bone quality affects the results of bone transplantation. Collagen cross-links (CCL) are the key factor in collagen properties. The purpose was to investigate the influences of CCL for both grafted bone and recipient site bone on the success of bone augmentation. Four-week-old male Wister rats (n = 54) were divided into control and test groups. Control and test groups equally sub-divided into donors and recipients. An additional six rats were used to characterize bone at day zero. Test groups received 0.2% beta-aminoproperionitrile (BAPN) for 4 weeks as CCL inhibitor. Animals were further divided into donor and recipient groups. The transplanted bone chips integrated with host bone by 25% more in CCL-deficient animals compared to control. However, no difference in cortical thickness among all conditions. CCL-deficient transplanted bone did not show any extra signs of osteocyte apoptosis, while sclerostin expression was comparable to that in control. The host periosteum of CCL-deficient animals showed higher cellular activity, as well as higher bone quantity and osteoclast activity. Collagen cross-links deficiency in host bone might accelerate the incorporation of grafted bone. effect. Incorporation of the bone grafts appears to depend mainly on host condition rather than graft condition.