The role of potassium chloride cotransporters in murine and human sperm volume regulation.
Article Details
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Klein T, Cooper TG, Yeung CH
The role of potassium chloride cotransporters in murine and human sperm volume regulation.
Biol Reprod. 2006 Dec;75(6):853-8. Epub 2006 Aug 30.
- PubMed ID
- 16943364 [ View in PubMed]
- Abstract
Spermatozoa need to undergo regulatory volume decrease (RVD) upon ejaculation to counteract swelling due to the hypo-osmolality of female tract fluids. Defects in sperm RVD lead to failure in both cervical mucus penetration in humans and utero-tubal junction passage in mice. The role of K/Cl cotransporters (KCCs) in RVD was investigated by incubation of spermatozoa from the murine cauda epididymidis and from human ejaculates in media mimicking female tract fluid osmolalities in the presence of KCC inhibitors. Furosemide at 100 microM or more caused swelling of murine spermatozoa as detected with a flow cytometer by increased laser forward scatter over 30 to 75 min of incubation. Bumetanide, known to have low affinity for KCCs, was effective at 1 mM, whereas 10 microM and 20 microM of the specific inhibitor DIOA (dihydroindenyl-oxy alkanoic acid) increased cell volume. These drug doses were ineffective in human spermatozoa, which, however, responded to quinine, confirming the occurrence of RVD under control conditions. The molecular identity of the murine KCC isoform involved was determined at both mRNA and protein levels. Conventional RT-PCR indicated the presence of transcripts from Slc12a4 (KCC1), Slc12a6 (KCC3), and Slc12a7 (KCC4) in the testis, whereas RT-nested PCR revealed the latter two isoforms in sperm mRNA. Of these three isoforms, only SLC12A7 (KCC4) was detected in murine sperm protein by Western blotting. Therefore, besides organic osmolyte efflux and KCl release through separate K(+) and Cl(-) ion channels, SLC12A7 also is involved in murine but not human sperm RVD mechanisms.
DrugBank Data that Cites this Article
- Drug Targets
Drug Target Kind Organism Pharmacological Action Actions Potassium chloride Solute carrier family 12 member 4 Protein Humans UnknownNot Available Details Potassium chloride Solute carrier family 12 member 6 Protein Humans UnknownNot Available Details Potassium chloride Solute carrier family 12 member 7 Protein Humans UnknownNot Available Details - Drug Transporters
Drug Transporter Kind Organism Pharmacological Action Actions Potassium chloride Solute carrier family 12 member 4 Protein Humans UnknownSubstrateDetails Potassium chloride Solute carrier family 12 member 6 Protein Humans UnknownSubstrateDetails Potassium chloride Solute carrier family 12 member 7 Protein Humans UnknownSubstrateDetails