Functional and morphological analysis of the main excretory duct V Investigation of tuft cells by high pressure freezing and freeze substitution

大鼠的颌下腺由构成初级唾液的分泌端和将初级唾液输送到口部的导管系统组成。胆管吻合口一般直径逐渐增大，其形态和生理定义依次为：插管、颗粒曲管、纹状管、排泄管、主要排泄管和唾液膀胱。除插管和颗粒曲管外，TULF细胞广泛存在于胃肠道、呼吸道等各种中空器官的粘膜上皮中。并提出了接受、重吸收、分泌等功能。然而，它们的功能仍然模糊不清。TULT细胞的高压冷冻和冷冻置换可使细胞内成分得到很好的保存。据推测，通过这项技术固定的组织仍处于活着状态。1997.1-1995年，我们建立了导管系统的细微结构，这从形态上说明了改变初唾液以形成最终唾液的贡献。2)我们建立了用镊子反复敲击唾液腺并在固定器中摇动唾液腺的技术。3)我们观察了导管系统的主细胞、丛状细胞和暗细胞的分布，并进行了形态计量分析。纹状管内分布有少量簇状细胞，多数分布在纹状管的门端。4)应用高压冷冻和冷冻替代技术(HPE-FS)对雄性大鼠颌下腺主排泄管的束状细胞进行冷冻。我们将HPF-FS的精细结构与传统的化学固定(CF)进行了比较。

The rat submandibular gland consists of the secretory endpices that form the primary saliva, and the duct system that conducts the primary saliva to the orifice. The ducts anastomosead generally progressively increase in caliber, and were defined morphologically and physiologically in turn as follows ; the intercalated duct, the granular convoluted duct, the striated duct, the excretory duct, the main excretory duct and the salivary bladder, Tuft cells are commonly present in the epithelium of the duct system except the intercalated and the granular convoluted ducts, Tulf cells have a widespread occurrence in the mucous epithelium of the various hollow organs such as gastrointestinal and respiratory tracts. Such functions as reception, the reabsorption and secretion are proposed. However, their functions are still obscure. High pressure freezing and freeze substitution of tult cells result in excellent preservation of intracellular component. It is supposed that tissue fixed by the technique remains in aliving state. Following results were obtained during 1995-1997.1) We established the fine structure of duct system except of the intercalated duct, which showed morphologically the contribution for modifying the primary saliva to make a final saliva.2) we developed thetechnique to elucidate acini of salivary gland by repeat of tapping a salivary gland with tweezers and shaking it in the fixation.3) We examined the distribution of principal, tuft and dark cells and performed morphometric analysis of the duct system. Few tuft cells were distributed in the striated duct and most were doung at the hilus. Dark cells were equally distribution through out the duct system.4) High pressure freezing and freeze substitution technique (HPE-FS) were appplied to tuft cells of the main excretory duct of male rat submandibular gland. We compared the fine structure of the HPF-FS with that obtained using conventional chemical fixation (CF).