Effects of arachnotoxin on intracellular pH and calcium in human spermatozoa

Effects of arachnotoxin on intracellular pH and calcium in human spermatozoa

Author Romero, Fernando Google Scholar
Cunha, Maria Adelaide Autor UNIFESP Google Scholar
Sanchez, Raul Google Scholar
Ferreira, Alice Teixeira Autor UNIFESP Google Scholar
Schor, Nestor Autor UNIFESP Google Scholar
Oshiro, Maria Etsuko Miyamoto Autor UNIFESP Google Scholar
Institution Universidade Federal de São Paulo (UNIFESP)
Univ La Frontera
Abstract Objective: To determine the effect of arachnotoxin (ATx), a venom extracted from the Chilean spider Latrodectus mactans, on intracellular calcium ([Ca2+](i)) and pH (pH(i)) in capacitated human spermatozoa.Design: Spermatozoa were collected from fertile adult men (n = 8). Mobile spermatozoa were collected by the swim up technique and stimulated with the crude extract of ATx and with progesterone (P).Setting: Hospital of the Federal University of São Paulo, São Paulo, Brazil.Main outcome measure(s): [Ca2+](i) was measured in fura2-AM-loaded spermatozoa, and pHi was measured in spermatozoa loaded with the pH-sensitive dye [(2',7')-bis (carboxymethyl)-(5,6)-carboxyfluorescein]-AM (BCECF).Result(s): the ATx and P induced a biphasic change in [Ca2+](i) consisting of a peak followed by a small but sustained elevation. the response to ATx was greatly reduced by pretreatment with P. the ATx caused intracellular acidification, whereas P induced alkalinization. Blockade of the NA(+)/H+ exchanger with ethylisopropylamiloride (EIPA) sharply increased ATx-induced acidification.Conclusion(S): Arachnotoxin increased [Ca2+](i) through the opening of calcium channels and release of calcium from intracellular stores. the ATx reduced pHi in human sperm, possibly by inhibiting the Na+/H+ exchanger.
Keywords arachnotoxin
human sperm
intracellular calcium
pH(i)
NA(+)/H+ exchanger
Language English
Date 2007-06-01
Published in Fertility and Sterility. New York: Elsevier B.V., v. 87, n. 6, p. 1345-1349, 2007.
ISSN 0015-0282 (Sherpa/Romeo, impact factor)
Publisher Elsevier B.V.
Extent 1345-1349
Origin http://dx.doi.org/10.1016/j.fertnstert.2006.11.054
Access rights Open access Open Access
Type Article
Web of Science ID WOS:000247150100016
URI http://repositorio.unifesp.br/handle/11600/29755

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