Morphological Features And Peptidergic Nerve Positioning Of Testis Interstitial Tissue In Different Developmental Stages Yak (Bos Grunniens)

The Yak is one of the ordinary domestic animal of Qinghai-Tibetan Plateau,while anatomical evidence of its special testicular morphological features adaptabilityto the high altitude environment is still less. Our research attempts to show themorphological characteristics of yak testis by the histology methods and transmissionelectron microscopy technology, in combination with immunohistochemical methodsto exploring morphological features and peptidergic nerve positioning of testisinterstitial tissue in immature stage, sexual maturation and aging yak(Bos grunniens),analyzes its relationship between testicular blood vessels, sperm production functionand the plateau adaptability, for further study of yak reproductive physiology toprovide morphologic reference.The results show that:1) The yak testis interstitial was distributed mainly by collagen fiber and reticularfiber, the distribution of fibrosis in connective tissue increased by the change of age.The Leydig cell development is not mature in juvenile yak, its typical structure wasappeared in mature yak, but the Leydig cells in clustering was more obvious inagingperiod, the testicular spermatogenic function was affected by the accumulation ofintracellular metabolites.2) The testicular tunicle and interstitial vascular was very rich in different ageyak, the innermost layer of the arterial wall was elastic fibers, surrounded by a largedistribution of collagen and reticular fibers. The vascular wall fiber content andcomposition changed accordingly with different developmental stages of yak,providing a rich blood supply to the testis, also is a necessary condition for the normalphysiological function of the testis.3) Peptidergic nerve protein factors mainly located in the vascular of differentdevelopment stages of yak. Peptidergic nerve and Leydig cells are closely linked, thetesticular vascular system was adjusted mainly by neurotransmitter and strongvasomotor factors, it makes the neurotransmitter rapidly and specifically in Leydigcells. Peptidergic nerve can be directly affect on the spermatogenic cells, regulation ofspermatogenesis and differentiation.To sum up, testis interstitial morphological structure were changed in immature,sexual maturation and aging yak. Location and distribution of PGP9.5and NPYpositive expression in the testis was different, suggest that peptidergic nerve always asimportant nerves play modulatory effects on testicular blood flow and the androgenproduction. Hence, it is the important role of adaptive regulation of Plateau Yakreproductive physiology.