Covant H A, Hardy M H
Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Canada.
J Exp Zool. 1990 Mar;253(3):271-9. doi: 10.1002/jez.1402530306.
Many morphogenetic processes are modified or initiated by retinoids. The cheek pouch of the newborn hamster can be induced to develop mucous glands in vitro by adding excess retinoid. The objective of this study was to determine whether the retinoid acted through the epithelium or the mesenchymal stroma. Explants of cheek pouch were grown for 7 days in either standard medium, or medium supplemented with 6 micrograms/ml retinyl acetate (RAc; 1.8 x 10(-5) M). After separation of most explants into epithelium and mesenchyme by trypsinization, the separated tissues were recombined in all possible ways and cultured for a further 1-2 weeks in standard medium. All explants were analysed histologically and/or histochemically from complete serial paraffin sections. No glands were formed in 30 recombinants containing stroma that had not been exposed to RAc, but four of 25 recombinants containing previously exposed stroma had glands, as well as four of 18 unseparated explants exposed to RAc. Exposure of epithelium to RAc did not result in the incidence of glands. It was concluded that RAc acting through the stroma was responsible for the instructive interaction with the epithelium for gland formation. A molecular mechanism is suggested.
许多形态发生过程会被视黄酸修饰或启动。通过添加过量视黄酸，新生仓鼠的颊囊可在体外诱导形成黏液腺。本研究的目的是确定视黄酸是通过上皮还是间充质基质起作用。将颊囊外植体在标准培养基或添加了6微克/毫升醋酸视黄酯（RAc；1.8×10⁻⁵ M）的培养基中培养7天。在通过胰蛋白酶消化将大多数外植体分离为上皮和间充质后，将分离的组织以所有可能的方式重新组合，并在标准培养基中再培养1 - 2周。从完整的系列石蜡切片对所有外植体进行组织学和/或组织化学分析。在30个含有未接触过RAc的基质的重组体中未形成腺体，但在25个含有先前接触过RAc的基质的重组体中有4个形成了腺体，在18个接触过RAc的未分离外植体中有4个也形成了腺体。上皮暴露于RAc并未导致腺体的发生率增加。得出的结论是，通过基质起作用的RAc负责与上皮进行关于腺体形成的诱导性相互作用。提出了一种分子机制。
