Linked Life Data

9540823

Source:http://linkedlifedata.com/resource/pubmed/id/9540823

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1998-4-23
pubmed:abstractText
Acrosome reaction inactivation (ARI) is a process that renders sperm irreversibly refractory to the egg jelly (the natural inducer of the acrosome reaction, AR). This process triggered by the egg jelly, is associated with an increase in [Ca2+]i. However, we show here that a rise in [Ca2+]i alone is not sufficient to induce ARI, since artificially increasing [Ca2+]i with either an ionophore or rising external pH, does not trigger ARI. Contrary to the AR which strictly requires Ca2+, ARI can be triggered almost equally well by Sr2+. On the other hand, Mn2+ inhibits ARI and, as we showed earlier, does not affect AR. These observations indicate that the mechanisms involved in ARI differ from those leading to AR. In addition, we report here that high external pH (a non-physiological inducer of AR) triggers the AR in previously inactivated sperm by opening the same Ca2+ channels activated by the egg jelly. Considering that the opening of Ca2+ channels is one of the earliest responses triggered by the egg jelly and that ARI requires the egg jelly receptor to be activated, we have concluded that ARI involves the uncoupling between the egg jelly receptor and Ca2+ channels. Furthermore, intracellular pH (pHi) determinations, in the presence or absence of ionomycin to substitute for the uncoupled Ca2+ channels, indicate that pHi regulation is also impaired in inactivated sperm. In conclusion, ARI is a manifestation of the uncoupling of the egg jelly receptor from the different ion transport systems required for the acrosome reaction.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
1401
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
329-38
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Acrosome reaction inactivation in sea urchin sperm.
pubmed:affiliation
Departamento de Bioquímica, CINVESTAV-IPN, Mexico D.F., Mexico.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't