Single-channel response of hamster oocytes to fertilization with homologous spermatozoa
Biocell
; 30(1): 43-49, abr. 2006. ilus, tab
Article
in English
| LILACS
| ID: lil-448077
Responsible library:
AR40.1
ABSTRACT
Electrophysiological events occur early after fertilization, along with changes in intracellular Ca2+ concentration. Passive electrical parameters were determined in golden hamster oocytes by whole cell patch-clamp method. In separate experiments the effect of 4-aminopyridine on resting oocytes was tested. The single-channel patch clamp configuration was employed to assess the electrical response to fertilization with homologous sperm. Structure of oocytes submitted to patch clamp was evaluated with scanning electron microscopy and found to be preserved.Oocyte diameter was 70.2 ± 2.2 µm; their resting parameters were membrane potential 23.8 ± 0.8 mV; total membrane specific resistance 519.1 ± 94.6 Ù.cm2, and specific capacity 0.99 ± 0.03 µF.cm-2. Total membrane current was decreased by 42 % by 4-aminopyridine.Control oocytes and oocytes exposed to sperm differed in their membrane currents in response to a voltage ramp clamping membrane potential from - 100 mV to + 100 mV. In both cases, currents were largest at the most negative potentials, but sperm-exposed oocytes had larger currents. Additionally, while in controloocytes the current was inward at negative potentials but outward at positive potentials, in the presence of spermatozoa oocytes was inward within the whole voltage range tested. This latter current may represent Ca2+ en try
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Collection:
International databases
Database:
LILACS
Main subject:
Oocytes
/
Mesocricetus
/
Patch-Clamp Techniques
/
Potassium Channel Blockers
/
Fertilization
Limits:
Animals
Language:
English
Journal:
Biocell
Journal subject:
Clulas
Year:
2006
Document type:
Article
Affiliation country:
Argentina
Institution/Affiliation country:
Universidad Nacional de Cuyo/AR