title: Electroporation of inositol 1,4,5-triphosphate induces repetitive calcium oscillations in murine oocytes.
abstract: The purpose of these experiments was to determine the effect of electroporation of IP3 into the cytosol of murine secondary oocytes and evaluate any alterations in [Ca2+]i resulting from Ca2+ release from intracellular stores. In addition, we evaluated the effect of ethanol (ETOH) on the release of Ca2+ from intracellular stores. Oocytes were loaded with the Ca2+ indicator fluo-3 by incubation in 100 microliters drops of medium containing 2 microM fluo-3/AM for 60 min at 37 degrees C. Changes in fluorescence were monitored by use of an inverted microscope which had been connected to a spectrofluorometer. Fluorescent intensity measurements were acquired for a minimum of 416 sec time span or up to 1,248 sec, with integration readings of 1 sec duration obtained every 2 sec throughout the measurement period. The experimental design consisted of comparing the rise in [Ca2+]i of fluo-3 loaded secondary oocytes subjected to electroporation in PBS and Ca(2+)-free PBS, each containing 25 microM IP3, to that elicited by PBS and Ca(2+)-free PBS containing a final concentration of 7% ETOH. Non-pulsed control secondary oocytes were placed in PBS + 25 microM IP3 during monitoring of [Ca2+]i fluorescence. Pulsed control secondary oocytes were placed in Ca(2+)-free PBS, subjected to electroporation pulse, and monitored for [Ca2+]i fluorescence. Electroporation of IP3 was accomplished by placing fluo-3 loaded secondary oocytes between the electrodes of a glass slide fusion chamber which had been overlaid with 300 microliters of PBS + 25 microM IP3 or Ca(2+)-free PBS + 25 microM IP3.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Animal, Dairy and Veterinary Sciences, Biotechnology Center, Utah State University, Logan 84322-4815.
authors.forename: L F
authors.initials: LF
authors.lastname: Rickords
authors.forename: K L
authors.initials: KL
authors.lastname: White
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism; D000431:Ethanol / Q000494:pharmacology; D005260:Female; D066298:In Vitro Techniques; D015544:Inositol 1,4,5-Trisphosphate / Q000502:physiology*; D051379:Mice; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism*
chemical_list: D000431:Ethanol; D015544:Inositol 1,4,5-Trisphosphate; D002118:Calcium