Morphofunctional analysis of the testis and spermatogenesis in adult African lions (Panthera leo, Linnaeus, 1758) / Análise morfofuncional do testículo e espermatogênese de leões africanos (Panthera leo, Linnaeus, 1758) adultos

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

The study of the testis morphology and the spermatogenetic process in wild animals is fundamentally important for the knowledge about the physiologic patterns by which the assisted reproduction protocols are established. The following objectives were proposed in this study: to describe the data of both testis morphometry and seminiferous tubule; to quantify the population relationships of the seminiferous epithelium, Sertoli cell indexes, and the testis spermatic reserve, as well as to characterize and describe the arrangement of the intertubular space components in adult African lions (Panthera leo) kept in captivity. So, testis fragments taken from five adult lions proceeding from zoological parks located in São Paulo and Minas Gerais states. The animals were submitted to testis biopsies in order to obtain biological material for the histological evaluation of the obtained fragments. The average body weight of these animals was 183.7 kg, from which 0.015% were allocated in testis mass and 0.009% were specifically in the seminiferous tubules that represented 75.6% of the testis parenchyma. The average diameter of the seminiferous tubules was 252.7 m and the average thickness of the seminiferous epithelium was 93.2 μm. The African lions averaged 12.3 meters for seminiferous tubule per testis gram. In these animals seminiferous epithelium, 10.3 primary spermatocytes at preleptotene phase are produced by A-type spermatogonia. During meiotic divisions, only 2.7 spermatids were produced from primary spermatocytes. The general spermatogenesis production of the African lions kept in captivity was 22.1 cells, and each Sertoli cell was able to sustain and maintain 14.9 cells of the germinative line, from which 7.9 are round spermatids. At each seminiferous epithelium cycle, approximately 103 million spermatozoids are produced by each gram of testis. In relation to the intertubular compartment in African lions testis, about 16% of the testis parenchyma is occupied by Leydig cells, 7.1% by conjunctive tissue, and 0.7% by blood vessels. The average volume of the Leydig cells and their average nuclear diameter were found to be 2578 μm3 and 7.1 μm, respectively. The Leydig cells occupied 0.0019% of the corporal weight, on the average, and their average number for each testis gram was superior to that found for most mammals, as exceeding 50 million.

ASSUNTO(S)

leões africanos espermatogênese morfologia testis morphology spermatogenesis morfologia testicular african lions

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