Chronic central administration of Ghrelin affects sperm morphology in mice

MARIA BELEN PORETTI; BIANCONI SANCIAGO; ANA CAROLINA MARTINI; EUGENIA LUQUE; MARINA PONZIO; LAURA VICENTI; MARTA FIOL DE CUNEO; VALERIA PAOLA CARLINI

Córdoba

Congreso; XVI Jornada de Investigación Científica de la Facultad de Ciencias Médicas; 2015

Facultad de Ciencias Medicas. Universidad Nacional de Cordoba

Physiological mechanisms that control energy balance are reciprocally related to those controlling reproductive function. In our lab we have shown that chronic intrahypothalamic Ghrelin (Ghr) administration (42 days), an orexigenic peptide containing 28 amino acids, inhibits epididymal sperm motility and decreases sperm concentration in mice.In this study, we investigated the effects of chronic central administration of Ghr on testicular histology and morphometry, sperm morphology and plasmatic testosterone concentration. Albino Swiss adult mice were implanted at intrahypothalamic level with osmotic pumps model 2006 (0,15 µl/hour-42 days) and infused with steril cerebrospinal fluid (LCR-control) or with different Ghr doses (0,3 or 3,0 nmol/ µl). Testicular histology and morphometry were determined after treatment by light microscopy, evaluating: seminiferous tubules diameter, length and area of seminiferous epithelium, number of: spermatogonia, spermatocytes, spermatids, sperm cells, Leydig and Sertoli cells, while sperm morphology was studied by electron microscopy (EM). Results show that Ghr administration (3,0 nmol/μl) for 42 days induced a decrease in spermatogonia and sperm percentage (F = 2, 1492; df = 12; p ≤ 0.05). No significant differences were found in percentage of Sertoli cells, Leydig cells and the rest of morphometric parameters studied (p> 0.05). Ghr 3.0 nmol/ul significantly decreased testosterone plasma levels (F = 16.69, df = 2). Sperm cell of mice treated with Ghr 3.0 nmol/ul exhibited morphological changes in head: abnormal morphology, small acrosome, not condensed chromatin, suggesting that Ghr could affect microtubules that are in core vicinity (manchette), whose function is to lengthen the sperm head and help compact the chromatin.This study provides new evidence about the effects of Ghr chronic administration on male reproductive system, indicating that the peptide induces at central level, a negative modulation that affects spermatogenesis, results that correlate with a reduction in plasma testosterone concentration.