黑眶蟾蜍背腹皮肤显微结构及其功能适应性的研究

Study on Microstructure and Functional Adaptability of Dorsal and Ventral Skin of Duttaphrynus melanostictus

利用石蜡切片和H.E染色技术,比较观察了黑眶蟾蜍背腹皮肤的显微结构.结果表明,黑眶蟾蜍的皮肤厚度在400~600μm,分为表皮和真皮.表皮为多层上皮细胞,由外向内包括角质层、颗粒层、棘细胞层和生发层.真皮分为疏松层和致密层,疏松层分布着少量粘液腺、颗粒腺和血管.研究还在背部疏松层中发现了两种特殊的皮肤钙化结构——钙化层和钙化斑.黑眶蟾蜍皮肤整体较厚,角化程度高,颗粒腺大,粘液腺数量少.背部较腹部皮肤厚,表皮层数多,角化程度高,兼具两种钙化结构,色素细胞和皮肤腺发达,防护能力更强;腹部更薄且血管化更高,对水通透性好,且具有利于吸水的小沟壑,这些结构特点与差异都反映了黑眶蟾蜍背腹两侧皮肤在适应干燥陆地环境上的作用是不同的.

In this study,the microstructure of the dorsal-ventral skin of Duttaphrynus melanostictus was observed and compared with light microscope by paraffin section and H.E staining techniques.The results showed that the skin of the Duttaphrynus melanostictus was divided into epidermis and dermis,with a thickness of 400~600μm.The epidermis is composed of several layers of epithelial cells,including the stratum corneum,granular layer,spinous layer and germinal layer from the surface to the basilar membrane.The dermis is divided into a stratum spongiosum and stratum compactum.The stratum spongiosum contains a large number of loose connective tissues,among which are mucous glands,granular glands and capillary vessels.In stratum spongiosum,two special forms of skin calcification,calcified layer and calcified spot,were found.The skin of Duttaphrynus melanostictusis thicker compared with other anurans,with a higher degree of keratinization,larger granular glands,and less mucous glands.The dorsal skin is thicker than the ventral skin,with more layers of epidermis and higher degree of keratinization,more plentiful of pigment cells and skin glands,with the addition of the two kinds of calcification structure,therefore had stronger protection ability.Whereas the ventral skin was thinner,higher vascularization,and there were many small grooves on surface of the skin,which mean that the ventral skin had a good water permeability,and was conducive to water absorption.The differences in the structure of the skin between the dorsal and the ventral reflects the different roles of both sides in the adaptation to the dry environment.