Biomaterial Database

An analysis of transport, exchange, and binding of sodium and potassium in isolated amphibian follicles and denuded oocytes. 1977

G A Morrill, and D Ziegler, and V S Zabrenetzky

The uptake and efflux of 22Na and 42K were studied in fully grown, prophase-arrested Rana pipiens follicles and denuded oocytes. Follicles and denuded oocytes contained large stores of both cations, although only 15--30% of the total Na+ and 1--2% of the total K+ pools exchanged within the 12-h period studied. 22Na uptake and efflux in follicles exhibited two-step kinetics with a smaller rapidly exchanging fraction (12--15%, t0-5 approximately 15 min), and a larger slow fraction (t0-5 approximately 0-5 day). Denuded oocytes displayed a single kinetic fraction with a rate constant similar to the slow fraction of follicles, suggesting that the fast fraction was associated with the follicular epithelium. Both follicles and denuded oocytes exhibited fast and slow 42K uptake kinetic fractions, although the follicular fast fraction was considerably larger. Conversely, whereas follicular 42K efflux also proceeded with two-step kinetics, 42K efflux from denuded oocytes appeared as a single slow fraction. Thus, a large portion of the fast K+ fraction taken up by the follicles is attributable to the somatic cells of the follicular envelopes. Na+ and K+ activities were measured in the cytoplasm of the in situ (follicular) oocyte using cation-selective microelectrodes. After correcting for Na+ and K+ associated with the follicular envelopes, only about 6% of the total ooplasmic Na+ and less than 1% of the K+ could be accounted for as bound or sequestered.

UI	MeSH Term	Description	Entries
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
D010063	Ovum	A mature haploid female germ cell extruded from the OVARY at OVULATION.	Egg,Egg, Unfertilized,Ova,Eggs, Unfertilized,Unfertilized Egg,Unfertilized Eggs
D011188	Potassium	An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
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
D002467	Cell Nucleus	Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)	Cell Nuclei,Nuclei, Cell,Nucleus, Cell
D005260	Female		Females
D006080	Ovarian Follicle	An OOCYTE-containing structure in the cortex of the OVARY. The oocyte is enclosed by a layer of GRANULOSA CELLS providing a nourishing microenvironment (FOLLICULAR FLUID). The number and size of follicles vary depending on the age and reproductive state of the female. The growing follicles are divided into five stages: primary, secondary, tertiary, Graafian, and atretic. Follicular growth and steroidogenesis depend on the presence of GONADOTROPINS.	Graafian Follicle,Atretic Follicle,Ovarian Follicles,Atretic Follicles,Follicle, Atretic,Follicle, Graafian,Follicle, Ovarian,Follicles, Atretic,Follicles, Graafian,Follicles, Ovarian,Graafian Follicles
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001001	Anura	An order of the class Amphibia, which includes several families of frogs and toads. They are characterized by well developed hind limbs adapted for jumping, fused head and trunk and webbed toes. The term "toad" is ambiguous and is properly applied only to the family Bufonidae.	Bombina,Frogs and Toads,Salientia,Toad, Fire-Bellied,Toads and Frogs,Anuras,Fire-Bellied Toad,Fire-Bellied Toads,Salientias,Toad, Fire Bellied,Toads, Fire-Bellied