Chloride channels are involved in sperm motility and are downregulated in spermatozoa from patients with asthenozoospermia.
Human spermatozoa encounter an osmotic decrease from 330 to 290 mOsm l-1 when passing through the female reproductive tract. We aimed to evaluate the role of chloride channels in volume regulation and sperm motility from patients with asthenozoospermia. Spermatozoa were purified using Percoll density gradients. Sperm volume was measured as the forward scatter signal using flow cytometry. Sperm motility was analyzed using computer-aided sperm analysis (CASA). When transferred from an isotonic solution (330 mOsm l-1 ) to a hypotonic solution (290 mOsm l-1 ), cell volume was not changed in spermatozoa from normozoospermic men; but increased in those from asthenozoospermic samples. The addition of the chloride channel blockers, 4,4'-diisothiocyanatostilbene-2,2'- isulfonic acid (DIDS) or 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB) to the hypotonic solution caused the normal spermatozoa to swell but did not increase the volume of those from the asthenozoospermic semen. DIDS and NPPB decreased sperm motility in both sets of semen samples. The inhibitory effect of NPPB on normal sperm motility was much stronger than on spermatozoa from the asthenozoospermic samples. Both sperm types expressed ClC-3 chloride channels, but the expression levels in the asthenozoospermic samples were much lower, especially in the neck and mid-piece areas. Spermatozoa from men with asthenozoospermia demonstrated lower volume regulating capacity, mobility, and ClC-3 expression levels (especially in the neck) than did normal spermatozoa. Thus, chloride channels play important roles in the regulation of sperm volume and motility and are downregulated in cases of asthenozoospermia.
Department of Pharmacology, Medical College, Jinan University, Guangzhou, China.|Department of Pathology and Pathophysiology, Medical College, Jinan University, Guangzhou, China.
Shan-Wen
SW
Liu
Department of Pathology and Pathophysiology, Medical College, Jinan University, Guangzhou, China.|Department of Physiology, Medical College, Jinan University, Guangzhou, China.
Yuan
Y
Li
Department of Physiology, Medical College, Jinan University, Guangzhou, China.
Li-Li
LL
Zou
Department of Pharmacology, Medical College, Jinan University, Guangzhou, China.|Department of Pathology and Pathophysiology, Medical College, Jinan University, Guangzhou, China.
Yu-Tao
YT
Guan
Department of Pathology and Pathophysiology, Medical College, Jinan University, Guangzhou, China.|Department of Physiology, Medical College, Jinan University, Guangzhou, China.
Shuang
S
Peng
Male Reproductive Center, Family Planning Special Hospital of Guangdong, Guangzhou, China.
Li-Xin
LX
Zheng
Male Reproductive Center, Family Planning Special Hospital of Guangdong, Guangzhou, China.
Shun-Mei
SM
Deng
Department of Pharmacology, Medical College, Jinan University, Guangzhou, China.
Lin-Yan
LY
Zhu
Department of Pathology and Pathophysiology, Medical College, Jinan University, Guangzhou, China.
Li-Wei
LW
Wang
Department of Pharmacology, Medical College, Jinan University, Guangzhou, China.
Li-Xin
LX
Chen
D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid / Q000494:pharmacology; D000328:Adult; D000375:Aging; D053627:Asthenozoospermia / Q000378:metabolism*; D048429:Cell Size; D018118:Chloride Channels / Q000037:antagonists & inhibitors; D015536:Down-Regulation; D006801:Humans; D007038:Hypotonic Solutions; D008297:Male; D009579:Nitrobenzoates / Q000494:pharmacology; D009994:Osmolar Concentration; D055101:Semen Analysis; D013081:Sperm Motility; D013094:Spermatozoa / Q000378:metabolism* / Q000648:ultrastructure
C582873:CIC-7 protein, human; D018118:Chloride Channels; C115376:ClC-3 channel; D007038:Hypotonic Solutions; D009579:Nitrobenzoates; C058176:5-nitro-2-(3-phenylpropylamino)benzoic acid; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid