Avaliação morfofuncional do testículo de veado-catingueiro (Mazama gouazoubira Fischer, 1814)

• Main Author: Costa, Kyvia Lugate Cardoso
• Publication Date: 2009
• Format: Master thesis
• Language: por
• Source: LOCUS Repositório Institucional da UFV
• Download full: http://locus.ufv.br/handle/123456789/2216
• topic: Morfometria testicular; Espermatogênese; Túbulo seminífero; Intertúbulo; Mazama gouazoubira; Veado-catingueiro; Testis morphometry; Spermatogenesis; Seminiferous tubules; Intertbular compartment; Mazama gouazoubira; Brown brocket deer; CNPQ::CIENCIAS BIOLOGICAS::BIOLOGIA GERAL

In comparison to mammals of the family Cervidae from other continents, the South American cervids are the most understudied. Moreover, approaches aiming to establish the reproductive biology of neotropical cervids are scarce. In this way, the objective of this study was to characterize morphologically and morphometrically the testis of the brown brocket deer (Mazama gouazoubira), providing information to improve the understanding of the reproductive biology of this species. For that, we have used seven adult male brown brocket deers, kept in captivity. Testicular fragments were obtained by testicular biopsy incision. The average body weight of brown brocket deer was 17.14kg, from which 0.40% were allocated in gonads and 0.33% in seminiferous tubules, which represented 85.86% of the testis parenchyma. The brown brocket deer presented high percentage of corporal mass allocated to testes and seminiferous tubules, exhibiting the greatest values described for most of studied mammalian species. The calculated volume of albuginea of right and left testis was 3.52mL, representing 5.33% of the testis mass. The volume of both mediastina was 1g, corresponding to 1.53% of testis mass. Therefore, the testicular parenchyma corresponds to 93.14% of the testis in brown brocket deers, making up a volume of 64.88mL. The average diameter of seminiferous tubules was 224.43µm and the average thickness of the seminiferous epithelium was 69.58µm. The brown brocket deer has around 1418m of seminiferous tubules in both testes, or an average of 21.47m of seminiferous tubules per gram of testis. The testicular parenchyma in the brown brocket deer was composed of 4.48% of Leydig cells, 4.41% of connective tissue, 2.89% of lymphatic vessels, and 2.36% of blood vessels. The Leydig cells occurred in groups of varied number of cells, with no particular pattern of distribution, and were observed around blood vessels, near to lymph vessels or associated with the lamina propria of seminiferous tubules. The average volume of Leydig cells was 677.52μm3 and their average nuclear diameter was 7.18µm. The average nuclear volume of Leydig cells was 194.33µm3. The nuclei of Leydig cells corresponded, in average, to 29.01% of total cell volume. The average total volume of Leydig cells in both testes was 2.90mL. The Leydigosomatic index was 0.0084% and the total number of Leydig cells per gram of testis was more than 60 millions. This number of Leydig cells per gram of testis is higher than that reported for most mammals studied. The organizational pattern of the testicular parenchyma of the brown brocket deers used in this study was similar to that described for most studied mammalian species, although with specific variations in the proportion and volume of some elements of the testicular parenchyma. Regarding the intertubular compartment, the organizational pattern of the elements of this region was in accordance with the standard type II, described by Fawcett, but presented variations in the connective tissue, which was slightly swollen. The qualitative and quantitative description of testicular histology of Brown brocket deer help to understand its spermatogenic process, and to establish parameters of the reproductive biology of this wild species. Furthermore, the preliminary data presented in this study could help subsequent research using other species of Brazilian cervids, especially those endangered, making possible the preservation of those species.