Kronmiller J E, Beeman C S, Kwiecien K, Rollins T
Department of Orthodontics, School of Dentistry, Oregon Health Sciences University, Portland, USA.
Arch Oral Biol. 1994 Oct;39(10):839-45. doi: 10.1016/0003-9969(94)90015-9.
Retinoids have important roles in pattern formation during embryonic development and might act as endogenous morphogens. They are necessary for normal odontogenesis and excess retinol alters the pattern of odontogenesis producing supernumerary buds of the dental lamina in the diastema region of the mouse mandible. Because the metabolism of retinoids in the developing mandible is unknown, the effects of retinal (an intermediate metabolite in the local conversion of retinol to retinoic acid) on the patterning of odontogenesis were examined. Retinal produces supernumerary buds and enhanced epithelial proliferation in day-9 mandibles in vitro. The endogenous levels of retinal in the mandible at the time of initiation of odontogenesis were also measured by high-performance liquid chromatography. Retinal was detected only at day 10 and not at later stages of development. Local metabolism of this intermediate retinoid may be a rate-determining step in the production of active retinoid metabolites that may control the pattern of the dentition, which is established at the time of the appearance of the dental lamina at embryonic day 12.
维甲酸在胚胎发育过程中的模式形成中发挥着重要作用，可能作为内源性形态发生素。它们对于正常的牙胚发生是必需的，过量的视黄醇会改变牙胚发生模式，在小鼠下颌骨的间隙区域产生额外的牙板芽。由于发育中的下颌骨中维甲酸的代谢情况未知，因此研究了视黄醛（视黄醇局部转化为视黄酸过程中的中间代谢产物）对牙胚发生模式的影响。视黄醛在体外培养的第9天下颌骨中产生额外的芽并增强上皮细胞增殖。还通过高效液相色谱法测量了牙胚发生开始时下颌骨中视黄醛的内源性水平。仅在第10天检测到视黄醛，在发育后期未检测到。这种中间类视黄醇的局部代谢可能是产生活性类视黄醇代谢产物的限速步骤，这些代谢产物可能控制牙列模式，牙列模式在胚胎第12天牙板出现时就已确立。
