Accumulation of sodium and potassium ions in oocytes of the river lamprey Lampetra fluviatilis at the prespawning period

Sherstobitov, A. O.; Lapin, A. V.; Glazunov, V. V.; Nikiforov, Vladimir; Nikiforov, A. A.

doi:10.1134/s0022093011040037

Cited by 2 publications

(2 citation statements)

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“…It should be noted that during the pre-spawning period, the chloride ion content in lamprey oocytes increases on average by 8 mmol/l (by 77%). Previously, we showed (Sherstobitov et al 2011) that from December to May, the intracellular content of sodium and potassium increases by a total of 32 mmol/l. From December to May intracellular Na + content increases on average from 10 mmol to 28 mmol, K + content from 28 mmol to 45 mmol (about 2-fold Chloride transport in lamprey oocytes 13 increase in total Na + and K + content).…”

Section: Discussionmentioning

confidence: 85%

“…A special study of anion transport on oocytes of cyclostomes has not been carried out. However, the study of transport of monovalent cations across the plasma membrane of lamprey oocytes (Sherstobitov et al 2003(Sherstobitov et al , 2008(Sherstobitov et al , 2010(Sherstobitov et al , 2011 showed that sodium and potassium transport is mediated by the ouabain-sensitive Na-Kpump and the bumetanide-sensitive NKCC cotransport mechanism. Thus, a part of the Cltransport in these cells is carried out along the NKCC pathway.…”

Section: Introductionmentioning

confidence: 99%

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Chloride Transport Across the Plasma Membrane of River Lamprey Oocytes During the Prespawning Period оf Their Life Cycle

Sherstobitov,

Nikitina,

Nikiforov

et al. 2024

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The permeability of follicle-enclosed isolated lamprey Lampetra fluviatilis oocytes to chloride was characterized during the pre-spawning season using 36Cl radioactive tracer. At physiological external [Cl-]o concentration of 150 mM a steady state equilibrium of the tracer corresponds to an apparent intracellular [Cl-]i concentration of 10.5 mM in December and 18.6 mM in April, with a half–time for chloride uptake about 20 min. The permeability coefficient for Cl- increased from 1.5 ⋅ 10− 6 cm/s (at 5oC) in December to 7.5 ⋅ 10− 6 cm/s (at 10oC) in May. The chloride influx was linearly dependent on [Cl-]o (0–150 mM) and was temperature dependent with an activation energy 24 kJ/mol at 5-20oC. Depolarization of the plasma membrane in high-K+ media in the presence of valinomycin stimulated Cl- influx approximately 2.5-fold. Decreasing medium tonicity resulted in 3-fold activation of Cl- influx compared with isotonic conditions. Exposure of the cells to 0.1–0.2 mM Cu2+ and 0.2 mM Cd2+ caused acceleration of Cl- influx, while 0.2 mM Pb2+, 0.2 mM Zn2+ and 0.15-5.0 mM (Ca2+ + Mg2+) were without effect. Treatment of the cells with ionophore A23187 in the presence of 5 mM Ca2+ also proved to be ineffective. Bumetanide-sensitive NKCC provided less than 5% of the total Cl- influx. In April, Cu2+ caused approximately 4,5-fold increase in the amiloride-sensitive component of Na+ influx, which most likely represented the NHE mechanism. Obtained results suggest the presence of a channel-mediated entry mechanism for chloride.

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Section: Discussionmentioning

confidence: 85%