Volume regulation of mature and immature spermatozoa in a primate model, and possible ion channels involved
Authors: C.H. Yeung; J.P. Barfield; M. Anapolski; T.G. Cooper
Source: Human Reproduction, Volume 19, Number 11, November 2004 , pp. 2587-2593(7)
Publisher: Oxford University Press
Abstract:BACKGROUND: Human ejaculated sperm undergo volume regulation, and swollen cells fail to penetrate mucus. Study of an infertile mouse model indicates maturation of volume regulation mechanism in the epididymis. METHODS: Sperm from the ejaculate and three regions of the epididymis of the cynomolgus monkey (Macaca fascicularis) were dispersed in BWW medium and changes in the cell volume and kinematics, and their responses to ion channel blockers, were monitored by flow cytometry and motion analysis. RESULTS: Initially swollen cauda epididymidal spermatozoa regained their original volume within 20 min, but not in the presence of 0.25 mM quinine. Corpus epididymidal spermatozoa underwent such regulatory volume decrease (RVD) to a lesser extent, with a similar response to quinine. Caput sperm showed no swelling throughout incubation. The chloride channel inhibitor NPPB also caused swelling of cauda spermatozoa and both quinine and NPPB decreased the efficiency of forward progression. RVD of ejaculated spermatozoa was inhibited by the K+ channel blockers quinine and 4-aminopyridine (4-AP) but not by tetraethylammonium, Ba2+ or Gd3+ , or the specific potassium channel blockers charybdotoxin, margatoxin, dendrotoxin, apamin, glybenclamide or clofilium. Quinine and 4-AP also altered ejaculated sperm kinematics as reported in human ejaculated spermatozoa. CONCLUSIONS: Quinine- and 4-AP-sensitive (implying K+) and NPPB-sensitive (implying Cl-) channels are involved in RVD of primate sperm, which develop this volume regulatory ability in the epididymis.
Document Type: Research article
Publication date: 2004-11-01
- Human Reproduction features full-length, peer-reviewed papers reporting original research, clinical case histories, as well as opinions and debates on topical issues. Papers published cover the scientific and medical aspects of reproductive physiology and pathology, endocrinology, andrology, gonad function, gametogenesis, fertilization, embryo development, implantation, pregnancy, genetics, genetic diagnosis, oncology, infectious disease, surgery, contraception, infertility treatment, psychology, ethics and social issues. The highest scientific and editorial standard is maintained throughout the journal along with a rapid rate of publication.