Linked Life Data

1814930

Source:http://linkedlifedata.com/resource/pubmed/id/1814930

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1992-6-25
pubmed:abstractText
Guinea pig sperm were suspended in calcium-containing medium supplemented with various concentrations of the tetrasaccharide, stachyose. At concentrations up to and including 0.6 M, stachyose was without effect on the A23187-induced acrosome reaction. At 1.0 M stachyose, greater than 97% of sperm retained their acrosome after exposure to A23187, as judged by light microscopy. Electron microscopy demonstrated, however, that exocytotic membrane fusion had occurred, although with substantial retention of the acrosomal matrix. Sperm incubated in 1.0 M stachyose solutions also underwent exocytotic membrane fusion in the absence of A23187 and external calcium. Sperm suspended in 0.175 M ammonium chloride solution progressively lost motility over 30 min, but without acrosomal swelling. By contrast, sperm in 0.19 M ammonium acetate underwent substantial swelling of the acrosome within 2-5 min. 70-80% of these sperm were able to exclude the vital dye propidium iodide with their acrosomes swollen. These sperm underwent acrosomal shrinkage if resuspended in normal medium within 5-10 min, and the majority (60-70%) recovered some motility. These sperm could undergo an A23187-induced acrosome reaction. Electron microscopy indicated that swelling in ammonium acetate solution solubilizes much of the acrosomal matrix and causes internal fusion between adjacent regions of the outer acrosomal membrane. There was no exocytotic membrane fusion in ammonium acetate solution, however. The evidence suggests that there is no stachyose osmolality for guinea pig sperm which will suppress the membrane fusion associated with exocytosis, and that sufficiently high osmolalities cause exocytotic membrane fusion in the absence of calcium.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0021-9533
pubmed:author
pubmed:issnType
Print
pubmed:volume
100 ( Pt 4)
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
761-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
The effect of permeant and impermeant osmoticants on exocytosis in guinea pig sperm.
pubmed:affiliation
Department of Pharmacology, University of Otago Medical School, Dunedin, New Zealand.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't