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Identification and expression of GABA C receptor in rat testis and spermatozoa

2008; Oxford University Press; Volume: 40; Issue: 8 Linguagem: Inglês

10.1111/j.1745-7270.2008.00453.x

1745-7270

Shifeng Li, Yunbin Zhang, Haixiong Liu, Yuanchang Yan, Yiping Li,

RNA Interference and Gene Delivery

Our previous studies showed that γ-aminobutyric acid (GABA)A and GABAB receptors are involved in rat sperm acrosome reaction induced by progesterone or GABA. Here, we report the presence of GABAC receptor in rat testis and spermatozoa. Full-length complementary DNA encoding the ρ1, ρ2 and ρ3 subunits of GABAC receptor were cloned from rat testis; their sequences are identical to those of rat GABAC receptor in retina. Reverse transcription-polymerase chain reaction analysis showed that during the development of rat testis, the transcript levels of the ρ1 and ρ2 subunits showed little change, while the expression of ρ3 was gradually up-regulated. Immunofluorescence analysis using an anti-ρl antibody revealed that GABAC receptor exists on the elongated spermatid and sperm. Using a chlortetracycline assay, we found that N(4)-chloroacetylcytosine arabinoside, a GABAC receptor agonist, triggered rat sperm acrosome reaction; whereas (1,2,5,6-tetrahydropyridin-4-yl) methylphosphinic acid, a GABAC receptor antagonist, inhibited the ability of N(4)-chloroacetylcytosine arabinoside to induce acrosome reaction. These results suggested that GABAC receptors are also involved in rat sperm acrosome reaction.