Abstract :
Background: ?-Aminobutyric acid (GABA) is considered to be the predominant inhibitory
neurotransmitter in mammalian central nervous systems (CNS). There are two major classes of GABA
receptors: GABAARs and GABABRs. The GABAA receptor is derived from various subunits such as
alpha?1-alpha 6, beta1-beta 3, gamma1-gamma 4, delta, epsilon, pi, and rho1-3. Intensive research has
been performed to understand and establish the distribution and functions of these receptors in the
CNS and peripheral tissues. The presence of some GABAA receptors in sperm prompted us to explore
the existence of GABAA receptors in rat testis and sperm.
Materials and Methods: Total cellular RNA was isolated from Wistar rat sperm and testis and
reverse transcriptased to cDNA. PCR reactions were performed in a 20?l (microliter) volume
containing specific GABAAR subunits (forward and reverse primers) with other required materials.
Reactions were carried out using a PCR machine to investigate the existence of GABAA receptor
subunits in rat testis and sperm. The amplification products were analyzed on 2% agarose gels
stained with ethidium bromide.
Results: Our results showed that GABAARs composed of ?5, B1, B3, and ?1 subunits were
expressed in both testis and sperm. These results indicate that, in sperm, GABAA receptors might
have important functions.
Conclusion:
Sperm could be a novel site of GABAA expression. Further studies should be taken to explore the
role of these receptors on sperm acrosome reaction.
