Biomaterial Database

NMR studies of intracellular sodium ions in amphibian oocytes, ovulated eggs, and early embryos. 1985

R K Gupta, and A B Kostellow, and G A Morrill

23Na NMR, in combination with an anionic paramagnetic shift reagent dysprosium bis(tripolyphosphate), has been used to study intracellular Na+ in Rana oocytes, ovulated eggs, and early cleavage embryos. The technique allows accurate and simultaneous determination of both extracellular space and intracellular Na+ concentration. In prophase-arrested, follicle-enclosed oocytes, only about 17% of the total oocyte Na+ (approximately 40 mmol/kg of cells) was NMR-visible. Homogenizing oocytes in 0.24 M sucrose did not significantly affect the 23Na resonance. About 30% of the total oocyte Na+ was associated with the yolk platelets isolated at room temperature by differential centrifugation. NMR analysis, however, did not yield a detectable 23Na signal from these intact platelets. Thus, while yolk platelets are rich in Na+, this Na+ does not contribute to the oocyte 23Na NMR signal. Denuded oocytes, obtained by removing the follicular epithelium, gained about 10 mmol of total Na+/kg of cells and exhibited a comparable increase in NMR-visible Na+, suggesting the existence of compartments with varying degree of NMR visibility within the oocyte. Partially relaxed 23Na Fourier transform NMR spectra revealed the existence of at least two major intracellular compartments of NMR-visible Na+ with different magnetic environments and relaxation behavior in denuded oocytes. Since platelet Na+ appears to be NMR-invisible, one of the two observed compartments may be the nucleus. Progesterone action on the amphibian oocyte caused measurable changes in NMR-visible Na+. By ovulation (second metaphase), there is a gain in total egg Na+, and the NMR-visible Na+ is also increased. Following fertilization, however, there is some loss of total cell Na+ but, by the 2-4 cell stage, about 70% of the total Na+ becomes NMR-visible. These results indicate that a sizable fraction of the Na+ in follicle-enclosed, prophase oocyte is sequestered and located in NMR-invisible compartments and that changes in NMR-visible intracellular Na+ occur following hormonal and developmental stimuli.

UI	MeSH Term	Description	Entries
D007424	Intracellular Fluid	The fluid inside CELLS.	Fluid, Intracellular,Fluids, Intracellular,Intracellular Fluids
D008677	Metaphase	The phase of cell nucleus division following PROMETAPHASE, in which the CHROMOSOMES line up across the equatorial plane of the SPINDLE APPARATUS prior to separation.
D009682	Magnetic Resonance Spectroscopy	Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).	In Vivo NMR Spectroscopy,MR Spectroscopy,Magnetic Resonance,NMR Spectroscopy,NMR Spectroscopy, In Vivo,Nuclear Magnetic Resonance,Spectroscopy, Magnetic Resonance,Spectroscopy, NMR,Spectroscopy, Nuclear Magnetic Resonance,Magnetic Resonance Spectroscopies,Magnetic Resonance, Nuclear,NMR Spectroscopies,Resonance Spectroscopy, Magnetic,Resonance, Magnetic,Resonance, Nuclear Magnetic,Spectroscopies, NMR,Spectroscopy, MR
D009865	Oocytes	Female germ cells derived from OOGONIA and termed OOCYTES when they enter MEIOSIS. The primary oocytes begin meiosis but are arrested at the diplotene state until OVULATION at PUBERTY to give rise to haploid secondary oocytes or ova (OVUM).	Ovocytes,Oocyte,Ovocyte
D010060	Ovulation	The discharge of an OVUM from a rupturing follicle in the OVARY.	Ovulations
D011374	Progesterone	The major progestational steroid that is secreted primarily by the CORPUS LUTEUM and the PLACENTA. Progesterone acts on the UTERUS, the MAMMARY GLANDS and the BRAIN. It is required in EMBRYO IMPLANTATION; PREGNANCY maintenance, and the development of mammary tissue for MILK production. Progesterone, converted from PREGNENOLONE, also serves as an intermediate in the biosynthesis of GONADAL STEROID HORMONES and adrenal CORTICOSTEROIDS.	Pregnenedione,Progesterone, (13 alpha,17 alpha)-(+-)-Isomer,Progesterone, (17 alpha)-Isomer,Progesterone, (9 beta,10 alpha)-Isomer
D011418	Prophase	The first phase of cell nucleus division, in which the CHROMOSOMES become visible, the CELL NUCLEUS starts to lose its identity, the SPINDLE APPARATUS appears, and the CENTRIOLES migrate toward opposite poles.	Prophases
D011894	Rana pipiens	A highly variable species of the family Ranidae in Canada, the United States and Central America. It is the most widely used Anuran in biomedical research.	Frog, Leopard,Leopard Frog,Lithobates pipiens,Frogs, Leopard,Leopard Frogs
D002453	Cell Cycle	The complex series of phenomena, occurring between the end of one CELL DIVISION and the end of the next, by which cellular material is duplicated and then divided between two daughter cells. The cell cycle includes INTERPHASE, which includes G0 PHASE; G1 PHASE; S PHASE; and G2 PHASE, and CELL DIVISION PHASE.	Cell Division Cycle,Cell Cycles,Cell Division Cycles,Cycle, Cell,Cycle, Cell Division,Cycles, Cell,Cycles, Cell Division,Division Cycle, Cell,Division Cycles, Cell
D004625	Embryo, Nonmammalian	The developmental entity of a fertilized egg (ZYGOTE) in animal species other than MAMMALS. For chickens, use CHICK EMBRYO.	Embryonic Structures, Nonmammalian,Embryo, Non-Mammalian,Embryonic Structures, Non-Mammalian,Nonmammalian Embryo,Nonmammalian Embryo Structures,Nonmammalian Embryonic Structures,Embryo Structure, Nonmammalian,Embryo Structures, Nonmammalian,Embryo, Non Mammalian,Embryonic Structure, Non-Mammalian,Embryonic Structure, Nonmammalian,Embryonic Structures, Non Mammalian,Embryos, Non-Mammalian,Embryos, Nonmammalian,Non-Mammalian Embryo,Non-Mammalian Embryonic Structure,Non-Mammalian Embryonic Structures,Non-Mammalian Embryos,Nonmammalian Embryo Structure,Nonmammalian Embryonic Structure,Nonmammalian Embryos,Structure, Non-Mammalian Embryonic,Structure, Nonmammalian Embryo,Structure, Nonmammalian Embryonic,Structures, Non-Mammalian Embryonic,Structures, Nonmammalian Embryo,Structures, Nonmammalian Embryonic