Cortical granule exocytosis in sea urchin eggs is inhibited by drugs that alter intracellular calcium stores

C. L. Stapleton, L. L. Mills, D. E. Chandler

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

In sea urchin eggs fertilization is accompanied by cortical granule exocytosis, a secretory event thought to be initiated by release of intracellularly sequestered calcium. We have examined the effect of two drugs on this process: chlortetracycline (CTC), a known chelator of intracellular calcium, and 8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate (TMB-8), an antagonist of intracellular calcium release in both skeletal and smooth muscle. Preincubation of eggs for 10 min with either CTC or TMB-8 blocked sperm entry, inhibited the burst of 45Ca2+ efflux normally seen postinsemination, and prevented fertilization envelope elevation. Half-maximal inhibition occurred with 200 μM CTC and 60 μM TMB-8. Electron microscopy confirmed that cortical granule exocytosis had been blocked, although inhibition was not due to a direct effect on exocytosis. CTC and TMB-8 had no effect on Ca2+-stimulated granule fusion in isolated egg cortices. Rather, these drugs block the early events in egg activation: sperm incorporation and triggering of exocytosis. These two effects appear to be independent since addition of either drug just before insemination permits sperm entry but inhibits calcium release and cortical granule exocytosis.

Original languageEnglish (US)
Pages (from-to)289-299
Number of pages11
JournalJournal of Experimental Zoology
Volume234
Issue number2
StatePublished - 1985

Fingerprint

cortical granules
Sea Urchins
exocytosis
Exocytosis
Chlortetracycline
Echinoidea
chlortetracycline
Eggs
Calcium
calcium
drugs
Spermatozoa
Pharmaceutical Preparations
fertilization (reproduction)
Fertilization
Ovum
spermatozoa
sperm capacitation
Insemination
chelating agents

ASJC Scopus subject areas

  • Animal Science and Zoology

Cite this

Cortical granule exocytosis in sea urchin eggs is inhibited by drugs that alter intracellular calcium stores. / Stapleton, C. L.; Mills, L. L.; Chandler, D. E.

In: Journal of Experimental Zoology, Vol. 234, No. 2, 1985, p. 289-299.

Research output: Contribution to journalArticle

Stapleton, C. L. ; Mills, L. L. ; Chandler, D. E. / Cortical granule exocytosis in sea urchin eggs is inhibited by drugs that alter intracellular calcium stores. In: Journal of Experimental Zoology. 1985 ; Vol. 234, No. 2. pp. 289-299.
@article{d2ddf8e60e254c25b44f9382ecba0fed,
title = "Cortical granule exocytosis in sea urchin eggs is inhibited by drugs that alter intracellular calcium stores",
abstract = "In sea urchin eggs fertilization is accompanied by cortical granule exocytosis, a secretory event thought to be initiated by release of intracellularly sequestered calcium. We have examined the effect of two drugs on this process: chlortetracycline (CTC), a known chelator of intracellular calcium, and 8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate (TMB-8), an antagonist of intracellular calcium release in both skeletal and smooth muscle. Preincubation of eggs for 10 min with either CTC or TMB-8 blocked sperm entry, inhibited the burst of 45Ca2+ efflux normally seen postinsemination, and prevented fertilization envelope elevation. Half-maximal inhibition occurred with 200 μM CTC and 60 μM TMB-8. Electron microscopy confirmed that cortical granule exocytosis had been blocked, although inhibition was not due to a direct effect on exocytosis. CTC and TMB-8 had no effect on Ca2+-stimulated granule fusion in isolated egg cortices. Rather, these drugs block the early events in egg activation: sperm incorporation and triggering of exocytosis. These two effects appear to be independent since addition of either drug just before insemination permits sperm entry but inhibits calcium release and cortical granule exocytosis.",
author = "Stapleton, {C. L.} and Mills, {L. L.} and Chandler, {D. E.}",
year = "1985",
language = "English (US)",
volume = "234",
pages = "289--299",
journal = "Journal of Experimental Zoology Part B: Molecular and Developmental Evolution",
issn = "1552-5007",
publisher = "John Wiley and Sons Inc.",
number = "2",

}

TY - JOUR

T1 - Cortical granule exocytosis in sea urchin eggs is inhibited by drugs that alter intracellular calcium stores

AU - Stapleton, C. L.

AU - Mills, L. L.

AU - Chandler, D. E.

PY - 1985

Y1 - 1985

N2 - In sea urchin eggs fertilization is accompanied by cortical granule exocytosis, a secretory event thought to be initiated by release of intracellularly sequestered calcium. We have examined the effect of two drugs on this process: chlortetracycline (CTC), a known chelator of intracellular calcium, and 8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate (TMB-8), an antagonist of intracellular calcium release in both skeletal and smooth muscle. Preincubation of eggs for 10 min with either CTC or TMB-8 blocked sperm entry, inhibited the burst of 45Ca2+ efflux normally seen postinsemination, and prevented fertilization envelope elevation. Half-maximal inhibition occurred with 200 μM CTC and 60 μM TMB-8. Electron microscopy confirmed that cortical granule exocytosis had been blocked, although inhibition was not due to a direct effect on exocytosis. CTC and TMB-8 had no effect on Ca2+-stimulated granule fusion in isolated egg cortices. Rather, these drugs block the early events in egg activation: sperm incorporation and triggering of exocytosis. These two effects appear to be independent since addition of either drug just before insemination permits sperm entry but inhibits calcium release and cortical granule exocytosis.

AB - In sea urchin eggs fertilization is accompanied by cortical granule exocytosis, a secretory event thought to be initiated by release of intracellularly sequestered calcium. We have examined the effect of two drugs on this process: chlortetracycline (CTC), a known chelator of intracellular calcium, and 8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate (TMB-8), an antagonist of intracellular calcium release in both skeletal and smooth muscle. Preincubation of eggs for 10 min with either CTC or TMB-8 blocked sperm entry, inhibited the burst of 45Ca2+ efflux normally seen postinsemination, and prevented fertilization envelope elevation. Half-maximal inhibition occurred with 200 μM CTC and 60 μM TMB-8. Electron microscopy confirmed that cortical granule exocytosis had been blocked, although inhibition was not due to a direct effect on exocytosis. CTC and TMB-8 had no effect on Ca2+-stimulated granule fusion in isolated egg cortices. Rather, these drugs block the early events in egg activation: sperm incorporation and triggering of exocytosis. These two effects appear to be independent since addition of either drug just before insemination permits sperm entry but inhibits calcium release and cortical granule exocytosis.

UR - http://www.scopus.com/inward/record.url?scp=0021917784&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0021917784&partnerID=8YFLogxK

M3 - Article

VL - 234

SP - 289

EP - 299

JO - Journal of Experimental Zoology Part B: Molecular and Developmental Evolution

JF - Journal of Experimental Zoology Part B: Molecular and Developmental Evolution

SN - 1552-5007

IS - 2

ER -