The prostate of the bat Artibeus lituratus: Seasonal variations, abiotic regulation, and hormonal control.

Abstract

The prostate is an important gland that contributes to the male reproductive process, producing secretions that are essential for maintaining ideal conditions for the survival of sperm. Studies indicate a wide variation in the occurrence, morphology, and physiology of this gland in mammals, especially in bats, with this variation being related not only to the number of regions and their degree of compaction/lobulation but also to fluctuations in their functioning throughout the year. Thus, the aim of this study was to evaluate the annual morphological and physiological variations of the male prostate of Artibeus lituratus and analyze their responses to annual abiotic variations and hormonal control. Sixty sexually adult males of A. lituratus were analyzed in this study, with five specimens collected monthly. Blood samples were submitted to serum hormone measurements and the prostates were morphologically, morphometrically, and immunohistochemically analyzed. The results indicated that the two prostatic regions (ventral and dorsal) of A. lituratus had different morphology, as well as different physiology and regulation. Annual fluctuations in abiotic factors seemed to influence the dorsal region more than the ventral region. Conversely, variations on testicular factors, such as testosterone and estradiol, influenced the ventral region more than the dorsal region. Despite these differences, both prostatic regions were strongly synchronized to the main reproductive peak of the species in September. The holocrine pattern of the ventral prostate was not directly affected by abiotic factors or by factors released by the testes.