Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 3 of 3
Full-Text Articles in Life Sciences
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 …
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 …