Brain-derived neurotrophic factor (BDNF) plays a role in the
development of various non-neuronal tissues, as the reproductive
system. BDNF transcript and protein has been detected in testis and
sperms. The present work aimed to assess the possible involvement of
BDNF mRNA expression in sperm functions, hormonal profile and
oxidative stress in male infertility. Semen samples from 106
individuals attended the Andrology Outpatient Clinic, Mansoura
University Hospital were included in the present study. They were
grouped into normozoospermia (n= 31), asthenozoospermia (n= 24),
astheno-teratozoospermia (n= 25) and Oligo-astheno-teratozoospermia
(n= 26). Reverse transcription-PCR (RT-PCR) for brain-derived
neurotrophic factor (BDNF) mRNA expression was done for semen
samples. The present study demonstrated that BDNF mRNA
expression was significantly decreased in the infertile samples
compared with the normozoospermic group. BDNF mRNA
expression was significantly positively correlated to testosterone
levels (r= 0.337, p= 0.0004) while, negatively correlated to folliclestimulating
hormone (FSH) (r= - 0.5, p
0.0001) and malondialdehyde
(MDA) /sperm levels (r= - 0.735, p
0.0001). Also, the study showed
significant positive correlation (p<0.0001) between BDNF mRNA
expression and sperm motility, velocity, linear velocity and linearity
index. Stepwise multiple regression analysis showed that sperm
morphology and alpha glucosidase may be possible determinants that
influence changes of BDNF expression. BDNF mRNA may directly
affect sperm functions and may be implicated in the pathophysiology of infertility. Furthermore, BDNF may have protection against oxidative stress.