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Full-Text Articles in Life Sciences
The Effects Of Copper, Cadmium And Zinc On Particle Filtration And Uptake Of Glycine In The Pacific Oyster Crassostrea Gigas, Wenyu Lin, Michael A. Rice, Paul K. Chien
The Effects Of Copper, Cadmium And Zinc On Particle Filtration And Uptake Of Glycine In The Pacific Oyster Crassostrea Gigas, Wenyu Lin, Michael A. Rice, Paul K. Chien
Michael A Rice
1. The filtration rate (volume of water completely cleared of collodial carbon per unit time) by control oysters is 36.60 ml/g hr ± 7.68 (sd).2. Filtration rates decrease with increasing concentrations of Cd2+ and Zn2+.3. In 8–16 mg/l Cu2+, filtration rates are significantly higher than the control, but in Cu2+ concentrations above 32 mg/l, filtration rates are lower than controls.4. Influx of 14C-glycine is characterized by Michaelis-Menten kinetics with Jmax and Kt values of 1.85 ± 0.097 μmol/g hr and 33.7 ± 4.6 μM respectively.5. The uptake rate of glycine from 1 μM solution is 37.79 μmol/g hr.6. In order …
Influx, Net Flux And Transepithelial Flux Of Amino Acids In The Hardshell Clam Mercenaria Mercenaria (Linne): Influence Of Salinity, Michael Rice, Grover Stephens
Influx, Net Flux And Transepithelial Flux Of Amino Acids In The Hardshell Clam Mercenaria Mercenaria (Linne): Influence Of Salinity, Michael Rice, Grover Stephens
Michael A Rice
1.1. The effects of salinity on the uptake and internal distribution of alanine and other free amino acids (FAA) in hardsell clams, Mercenaria, was studied by radiochemical and high performance liquid chromatography (HPLC) techniques.2.2. Exposure of animals to reduced salinity does not alter the rate of unidirectional alanine influx.3.3. In 34%o salinity, entry of labeled alanine reflects the net flux of the amino acid. However, in 17%o salinity, there is a net loss of alanine and other acids, mainly taurine, to the medium.4.4. Reduced salinity induces greater incorporation of radiolabeled FAA into macromolecular fractions throughout the animal.5.5. The major factors …
Influx And Transepithelial Flux Of Amino Acids In The Mussel, Mytilus Edulis., Michael A. Rice, Grover C. Stephens
Influx And Transepithelial Flux Of Amino Acids In The Mussel, Mytilus Edulis., Michael A. Rice, Grover C. Stephens
Michael A Rice
The uptake of amino acids by the non-gill epithelia of the mantle cavity of Mytilus edulis L. was studied and compared with uptake by the gills. Amino acid entry rates and the subsequent distribution of amino acids to the other tissues of the animals were studied using high-performance liquid chromatography and radiochemical techniques. Uptake via the non-gill epithelia lining the mantle cavity was separated from uptake via the gill by employing a preparation in which the gills were surgically removed. Amino acid uptake by such animals was compared with that of suitably sham-operated controls. In short-term experiments (up to 2h), …
Propagation Of Adherent Bacteria On The Brittlestar Ophionereis Annulata (Le Conte) After Enrichment Of Seawater With Amino Acids, Michael A. Rice
Propagation Of Adherent Bacteria On The Brittlestar Ophionereis Annulata (Le Conte) After Enrichment Of Seawater With Amino Acids, Michael A. Rice
Michael A Rice
Epidermal surfaces of the ophiouroid Ophionereis annulata (Le Conte) were examined by scanning electron microscopy. Microvilli, which are characteristic of many transport epithelia, are present on the epidermal surfaces. Epidermal surfaces of freshly-collected brittlestars were compared with brittlestars that were maintained in the laboratory for 48 hours in fresh seawater and in seawater enriched with 20uM glycine. Very few bacteria were observed on the surface of the freshly-collected animals or on animals maintained in the laboratory in fresh seawater. The epidermal surfaces of animals maintained in seawater enriched with 20 uM glycine showed extensive mats of coccoid and bacilloid bacteria. …
Uptake And Internal Distribution Of Exogenously Supplied Amino Acids In The Pacific Oyster, Crassostrea Gigas (Thunberg), Michael A. Rice, Grover C. Stephens
Uptake And Internal Distribution Of Exogenously Supplied Amino Acids In The Pacific Oyster, Crassostrea Gigas (Thunberg), Michael A. Rice, Grover C. Stephens
Michael A Rice
A technique is described in which irrigation of the mantle cavity of oysters, Crassostrea gigas, induces pumping at steady rates. Simultaneous net influx of 10 amino acids (asp, glu, asn, ser, gly, tau, ala, val, phe, lys) is observed by high-performance liquid chromatography (HPLC). Individual amino acids exhibit first-order exponential depletion from an initial medium concentration of 2.0 μM. Influx of radiolabeled alanine corresponds very closely to net entry of alanine as estimated by HPLC. Therefore, net entry of alanine from dilute solution (5 μM) occurs. The entry of alanine is well described by Michaelis-Menten kinetics with a maximum influx …
Autoradiographic Localization Of Exogenously Supplied Amino Acids After Uptake By The Polychaete, Glycera Dibranchiata Ehlers, Paul Chien, Michael Rice
Autoradiographic Localization Of Exogenously Supplied Amino Acids After Uptake By The Polychaete, Glycera Dibranchiata Ehlers, Paul Chien, Michael Rice
Michael A Rice
Localization of amino acid transport sites within the integument of Glycera dibranchiata Ehlers was carried out by freeze-section and freeze-dry histological techniques. The worms were exposed for one hour to the non-metabolizable amino acid analog c(14)-cycloleucine in seawater. Freeze-sectioning and freeze drying of tissue samples allows the localization of water soluble compounds by autoradiography. Amino acid uptake is largely across the parapodial gill surfaces and the epidermis. The gills become rapidly labelled with c(14)-cycloleucine to a greater extent than the epidermal cell layers. Coelomocytes within the gills become radiolabeled in one hour. It is suggested that the rapid labelling of …
Transport Of Dissolved Amino Acids By The Mussel, Mytilus Edulis: Demonstration Of Net Uptake From Natural Seawater, Donal T. Manahan, Stephen H. Wright, Grover C. Stephens, Michael A. Rice
Transport Of Dissolved Amino Acids By The Mussel, Mytilus Edulis: Demonstration Of Net Uptake From Natural Seawater, Donal T. Manahan, Stephen H. Wright, Grover C. Stephens, Michael A. Rice
Michael A Rice
High-performance liquid chromatography provides direct evidence for substantial removal of naturally occurring specific free amino acids during a single passage of water through the mantle cavity of mussels. This occurs during the few seconds required for passage of the water across the gill, and removal proceeds unabated at ambient concentrations as low as 38 nanomoles per liter.