Histological And Cytological Study On Pituitary Gland And Gonad Of Soft-shelled Turtle (Trionyx)

Histological and cytological structures of pituitary gland and gonad in Trionyx were investigated by light and electro-microscopy using several staining methods and immunocytochemistey reaction. The results showed that the pituitary gland(hypophysis) was divided as following parts:1. adnohypophysis(1) pars distalis(2) cephalic lobe of pars distalis (1) caudal lobe of pars distalis (2) pars tuberalis2. neurohypophysis(1) Infundibular(2) pars tuberalisIn pars distalis, three kinds of cells including acidophil, basopil and chromophobe were distinguished under light microscope, while six types of cells can be found under electro-microscopy, they are somatotroph, corticotroph, gonadotrops, prolactin, thyrotrope and chromophobic cell. All kinds of cells often appeared in groups, and plenty of fenestrated capillaries were among them. Pars intermedia was not found in the pituitary gland of Trionyx. The cephalic lobe of pars distalis was larger than the caudal lobe of pars distalis while there was a interstices between them. Pars tuberalis was very small and it was in front of the infundibular, where chromophobic cells were in group of gland-bubble. Infundibular was narrow and long part which made up of nervous fibre and Pars nervosa was not of a developted part which laying the back of the caudal lobe of pars distalis. At the same time it made up some finger-like structure projecting into the caudal lobe of pars distalis. Every kind of cells is often occurred at special area. And many kinds of cells have obvious cell junctions. The results of January and September were different in some extent. The granules in GtH cells always merge to larger ones in January. It was different not only from fish but also from mammal .Cell structure changed according to different seasons to some extentThe gonad of Trionyx was mainly made up of convoluted seminiferous tubule. There were not straight seminiferous tubule and rete testis. There were interstitial cells and capillary among convoluted seminiferous tubule. Various spermatogenic cells and supporting cells consisted of the wall of convoluted seminiferous tubules. Morphology of the spermatozoa liked as that of the mammal and the structure of the supporting cell was not clear under light microscope. Capillaries belonged to continuous ones, which mainly composed the structure of blood-tests barrier. Amount of lipid drops and smooth endoplasmic reticulum occurred in interstitial cells which often distributed in groups. In January. There were 1-2 layers of spermatogenesis cells in seminiferous epithilum. But pvts of the tubules were filled with mature spermatozoa, and interstitial cells were hardly to seen.The ovary of Trionyx contained many phases of ovarian follicles. The zona peluacida was obvious that enclosing growing follicle and mature follicle. There were 1-3 layers of follicular cells around the zona peluacida. Plenty of milli of ovum projected into zona pduacida. On the other side milli of follicular cells also projected into the zona peluacida. there were no follicle cavity and comulus oophorus in the follicle of Trionyx, which was different from mammalIn September, the weight of testis and ovary, and gonad coefficient was obviously higher than that of January. It indicated that there were obvious seasonal changes in reproductive activity of Trionyx. In September, the hormone levels of testoterone and estradiol were 0.12ng/ml and 0.69pg/ml,while in January, the level were 0.05ng/ml and 029pg/ml, which showed obvious changes.