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Titolo:
CYCLOPIAZONIC ACID INDUCES ACCELERATED PROGRESS OF MEIOSIS IN PIG OOCYTES
Autore:
PETR J; ROZINEK J; JILEK F;
Indirizzi:
RES INST ANIM PROD,UHRINEVES CR-10400 PRAGUE 10 CZECH REPUBLIC
Titolo Testata:
Zygote
fascicolo: 3, volume: 5, anno: 1997,
pagine: 193 - 205
SICI:
0967-1994(1997)5:3<193:CAIAPO>2.0.ZU;2-8
Fonte:
ISI
Lingua:
ENG
Soggetto:
INTRACELLULAR CA2+ STORES; INOSITOL 1,4,5-TRISPHOSPHATE RECEPTOR; GERMINAL VESICLE BREAKDOWN; INDUCED CALCIUM-RELEASE; MEIOTIC MATURATION; BOVINE OOCYTES; MOUSE OOCYTE; MAMMALIAN OOCYTE; HAMSTER OOCYTES; CELL-CYCLE;
Keywords:
CALCIUM; CYCLOPIAZONIC ACID; MATURATION; OOCYTE; PIG;
Tipo documento:
Article
Natura:
Periodico
Citazioni:
64
Recensione:
Indirizzi per estratti:
Citazione:
J. Petr et al., "CYCLOPIAZONIC ACID INDUCES ACCELERATED PROGRESS OF MEIOSIS IN PIG OOCYTES", Zygote, 5(3), 1997, pp. 193-205

Abstract

In mammalian oocytes, calcium plays an important role in the regulation of meiotic maturation. In our study, we used the mycotoxin cyclopiazonic acid (CPA), an inhibitor of calcium-dependent ATPases, to mobilise intracellular calcium deposits during in vitro maturation of pig oocytes. The CPA treatment of maturing oocytes significantly acceleratedthe progress of their maturation. Oocytes entered the CPA-sensitive period after 21 h of in vitro culture. A very short (5 min) exposure toCPA (100 mM) is sufficient to accelerate maturation and it seems thataccelerated maturation can be triggered by a transient elevation of intracellular calcium levels. The effect of CPA is not mediated throughthe cumulus cells, because maturation is accelerated by CPA treatmenteven in oocytes devoid of cumulus cells. Culture of oocytes with the calcium channel blocker verapamil (concentrations ranging from 0.01 to0.04 mM) blocked the progress of oocyte maturation beyond the stage of metaphase I. This block can be overcome by the mobilisation of intracellular calcium deposits after CPA treatment (100 nM). The microinjection of heparin (20 pl, 0.1 mg/ml), the inhibitor of inositol triphosphate receptors, before CPA treatment prevented the acceleration of oocyte maturation. This indicates that CPA mobilises the release of calcium deposits through inositol trisphosphate receptors. On the other hand, the microinjection of procaine (20 pl, 200 nM) or the microinjection of ruthenium red (20 pl, 50 mM), both inhibitors of ryanodine receptors, did not prevent accelerated maturation in CPA-treated oocytes. Ifpresent in pig oocytes, ryanodine receptors evidently play no part inthe liberation of calcium from intracellular stores after CPA treatment.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 29/11/20 alle ore 10:21:49