Dirksen T R, Schuster G S, McKinney R V, Bustos S E
Lab Invest. 1975 Feb;32(2):133-9.
The effect of beta-aminopropionitrile (BAPN) on lipid synthesis and 14CO2 production from 14C-acetate by rat calvariae in vitro was investigated by biochemical, histochemical, and autoradiographic techniques. Exposure of bones to 5 mM BAPN throughout a 5-hour incubation period resulted in little effect on lipid synthesis when compared with control bones. Higher BAPN concentrations, up to 100 mM, during this short incubation period resulted in enhanced lipid radioactivity for most of the identified lipid classes. Longer preincubation periods of 20 hours and low BAPN (20 mM) concentrations resulted in enhanced lipogenesis. As BAPN concentrations above 20 mM were employed, lipogenesis decreased to such a level that some lipid classes failed to become labeled with 14C-acetate. 14CO2 production from 14C-acetate by a rat calvariae was affected by BAPN concentration and incubation time in a pattern similar to that of lipid synthesis. Histochemistry demonstrated neutral fat in the osteogenic cells and phospholipids in osteoblasts and the osteoid matrix. Autoradiographic localization of 14C-acetate revealed that the radioactivity was in the osteogenic cells and that this activity was markedly increased after pretreatment of the calvariae with BAPN. This study shows that some concentrations of BAPN enhance lipogenesis by rat calvariae and supports the earlier suggestion that lipids play a role in biologic calcification.
采用生化、组织化学和放射自显影技术，研究了β-氨基丙腈（BAPN）对大鼠颅骨体外脂质合成以及14C-乙酸盐生成14CO2的影响。在5小时的孵育期内，将骨骼暴露于5 mM的BAPN中，与对照骨骼相比，对脂质合成几乎没有影响。在这个短孵育期内，高达100 mM的更高BAPN浓度导致大多数已鉴定脂质类别的脂质放射性增强。20小时的较长预孵育期和低BAPN（20 mM）浓度导致脂肪生成增强。当使用高于20 mM的BAPN浓度时，脂肪生成下降到某些脂质类别未能被14C-乙酸盐标记的水平。大鼠颅骨从14C-乙酸盐生成14CO2受到BAPN浓度和孵育时间的影响，其模式与脂质合成相似。组织化学显示成骨细胞中有中性脂肪，成骨细胞和类骨质基质中有磷脂。14C-乙酸盐的放射自显影定位显示，放射性存在于成骨细胞中，并且在用BAPN预处理颅骨后，这种活性明显增加。这项研究表明，某些浓度的BAPN可增强大鼠颅骨的脂肪生成，并支持早期关于脂质在生物钙化中起作用的观点。
