Na+ and K+ uptake and exchange by the amphibian oocyte during the first meiotic division

Morrill, Gene A.; Ziegler, David H.

doi:10.1016/0012-1606(80)90063-9

Cited by 33 publications

(16 citation statements)

References 10 publications

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“…Similar to the Na-K pump , the transport systems for thymidine, alanine, chloride, and phosphate show a regulatory decrease. These findings can be added to the previous observations on the transport of Omethyl-glucose (Carvallo et al, 1981), L-leucine (Ecker & Smith, 1971;Pennequin et al, 1975) and a passive component of K + transport that is independent of the alkali ion pump (Ziegler & Morrill, 1977;Morrill & Ziegler, 1980). The decrease of this latter component, together with that of the C1-permeability described here, may be responsible for the decrease of the electrical conductance of the membrane, which has been demonstrated previously (Bell~, Ozon & Stinnakre, 1977;Kado, Marcher & Ozon, 1981).…”

Section: Discussionsupporting

confidence: 72%

“…This suggests that the inhibition of passive ion movements (notably of K +) is controlled independently of the alkali ion pump. It has also been reported that the regulatory changes of potassium permeability occur without concomitant changes of sodium permeability (Morrill & Ziegler, 1980), suggesting that the passive movements of the principal alkali ions are also regulated separately. Thus, many important transport systems shut down at different times and therefore either have different thresholds for responding to the accumulation of the same inhibitor or they are regulated by different processes.…”

Section: Discussionmentioning

confidence: 98%

“…It is quite plausible, therefore, that oocyte maturation involves regulatory activity changes of the many transport systems in the plasma membrane (Pennequin, Schorderet-Slatkine, Drury & Baulieu, 1975;Bellr, Marot & Ozon, 1976;Ziegler & Morrill, 1977;Morrill & Ziegler, 1980; Carvallo, Albuja, Allende & Allende, 1981; Smith, 1981).…”

Section: Introductionmentioning

confidence: 98%

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Regulatory changes of membrane transport and ouabain binding during progesterone-induced maturation ofXenopus oocytes

1984

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During progesterone-stimulated maturation of defolliculated full-grown Xenopus oocytes, the activities of the transport systems for L-alanine, thymidine, chloride, phosphate, and alkali ions decrease. Differences of the extent and time course of these changes suggest that they are controlled by at least partially independent mechanisms. A closer investigation of the Na-K ATPase has shown that in unstimulated oocytes, ouabain produces maximal inhibition when 8-12 X 10(9) molecules are bound per cell. This number is bound during the first phase of a diphasic uptake process. Since this phase can be suppressed by increasing the concentration of external K+ to 45 mmol/liter or more, it is concluded that it refers to binding to the Na-K pump in the plasma membrane. Ouabain bound prior to progesterone-induced germinal vesicle breakdown (GVBD) remains bound after the breakdown, although the Na-K pump loses the capacity to bind ouabain after GVBD in oocytes that had not been exposed to ouabain preceding GVBD. In the presence of Mg++ membranes isolated before regulatory inhibition of pumping and ouabain binding show a Na+-dependent incorporation of 32P from gamma-[32P]-ATP that can be reversed by the addition of K+. The phosphorylation site migrates on LiDS-polyacrylamide gel electropherograms at about 98,000 daltons and can be identified as a Commassie blue-stainable band.

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Section: Discussionsupporting

confidence: 72%

Section: Discussionmentioning

confidence: 98%

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Regulatory changes of membrane transport and ouabain binding during progesterone-induced maturation ofXenopus oocytes

1984

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“…Major biochemical and biophysical changes occur in amphibian oocytes after the resumption of the meiotic divisions, including an increase in both protein synthesis and protein phosphorylation (9, 10, 11, 12) disappearance of an electrogenic Na+, K+ pump (13,14), and a decrease in K+ and C1-conductances of the oocyte plasma membrane (15,16,17). However, many of these studies were done with oocytes which were stripped of their somatic cell investment and/ or were induced by progesterone to undergo meiotic maturation.…”

mentioning

confidence: 99%

Increased Potassium Conductance in Rana Follicles after Stimulation by Pituitary Extract

Weinstein¹,

Morrill²,

Kostellow³

1983

Dev Growth Differ

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Pituitary gonadotropins are believed to induce the somatic cell portion of the amphibian follicle to synthesize and release progesterone which, in turn, induces the resumption of the meiotic divisions in the follicular oocyte. We report here that pituitary extract, at concentrations that induce ovulation and meiosis, causes a rapid hyperpolarization of the follicular oocyte. A similar hyperpolarization is seen in response to porcine LH but not FSH. Voltage clamp studies indicate that this is due to an increase in follicle K+ conductance. An electrical model of the amphibian follicle suggests that pituitary factors act by increasing the K+ conductance of the oolemma, by increasing the extent of oocyte-follicle cell ionic coupling, or by increasing the conductance of follicle cell plasma membrane. The conductance change does not occur in the absence of follicle cells, is not mediated by progesterone, and is not necessary for meiotic maturation, per se, but may play a role in processes which accompany or follow maturation.The vertebrate oocyte is arrested in first meiotic prophase until hormonal stimulation prior to ovulation. Recent studies using amphibian oocytes have elucidated many of the events in the sequence by which gonadotropins induce the resumption of the meiotic divisions. In brief, pituitary gonadotropins induce the somatic cell portion of the follicle to synthesize and release progesterone (1, 2, 3, 4, 5 ) which, in contrast to most of the other known steroid hormone/ receptor systems (6), then acts at the level of the oocyte plasma membrane to initiate meiotic maturation (7, 8).Major biochemical and biophysical changes occur in amphibian oocytes after the resumption of the meiotic divisions, including an increase in both protein synthesis and protein phosphorylation (9, 10, 11, 12) disappearance of an electrogenic Na+, K+ pump (13,14), and a decrease in K+ and C1-conductances of the oocyte plasma membrane (15, 16, 17). However, many of these studies were done with oocytes which were stripped of their somatic cell investment and/ or were induced by progesterone to undergo meiotic maturation. Thus, changes in follicle physiology induced by gonadotropin, the initial physiological stimulus of meiotic maturation, would necessarily not be manifest in these studies. Therefore, in an attempt to reveal early changes in follicle physiology in response to gonadotropin, we investigated the effect of pituitary extract on the electrophysiological properties of follicular oocytes from Rana pipiens. We report here that within one minute after introduction of pituitary extract into the bathing medium, follicles undergo a marked hyperpolarization which is mediated by an increase in K+ conduc-

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“…The coordination between Cl -and Na + currents seems to modulate oocyte maturation in the frog Rana pipiens in which Cl -channels disappear throughout maturation whereas the Na + currents remain active up to the full maturity of the oocyte (Baud 1983). In same species, an hormone-induced depolarization was also associated to a decrease in K + permeability (Morrill and Ziegler 1980). Together with these patterns, the fact that Cl -currents are lost as the oocyte undergoes maturation (Schlichter 1983) suggested that Cl -and Na + channels might play a regulatory role in maturation.…”

Section: The Oocytementioning

confidence: 97%

Ion currents involved in gamete physiology

Gallo¹,

Tosti²

2015

Int. J. Dev. Biol.

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Gametes are electrogenic cells that modify their electrical properties in response to different stimuli. This behavior is due to the occurrence of ion currents flowing through ion channels located on the plasma membranes. The modulation of ion channels has been described during the processes of gamete maturation, activation and fertilization in most of the animal models studied. In particular, predominant ions involved in physiological events in oocyte and sperm have been recognized to be sodium, potassium and calcium. In this review, we give an overview on the occurrence, modulation and function of ion fluxes, from gametogenesis to early fertilization events, from marine animals to human. The implications for a dynamic role of ion currents in gamete physiology and their possible clinical and technological applications are discussed.

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Na+ and K+ uptake and exchange by the amphibian oocyte during the first meiotic division

Cited by 33 publications

References 10 publications

Regulatory changes of membrane transport and ouabain binding during progesterone-induced maturation ofXenopus oocytes

Regulatory changes of membrane transport and ouabain binding during progesterone-induced maturation ofXenopus oocytes

Increased Potassium Conductance in Rana Follicles after Stimulation by Pituitary Extract

Ion currents involved in gamete physiology

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