Effects of Intracellular Zinc Chelator In Vivo on Taurine Transport,Taurine Concentrations and Taurine Transporter in Rat Retina Cells

We examined characteristics of taurine transport across renal brush-border membranes (BBM) of the garter snake (Thamnophis sirtalis), a species that demonstrates both net reabsorption and secretion of taurine in vivo. Transport was examined by a rapid filtration technique at 25 degrees C. Inwardly directed Na+ gradient specifically stimulated taurine uptake. Under initial taurine equilibrium condition, a small overshoot of taurine uptake driven by an inwardly directed NaCl gradient could be observed. No stimulation of taurine uptake was observed under Na+ equilibrium or K+, Li+, or choline gradients conditions. Reptilian renal BBM taurine transport also displayed specific Cl- requirement: replacement of NaCl by NaSCN or Na(+)-gluconate gradients inhibited taurine uptake. The uptake was stimulated under Cl- gradient compared with Cl- equilibrium conditions. Taurine transport was not stimulated by H+ gradient in either direction, although it was inhibited by acidic pH (less than 7.0). Amiloride and furosemide had no effects. The transport was electrogenic, stimulated by an inside negative membrane potential, and inhibited by other beta-amino acids. Overall, the reptilian BBM transport system for taurine resembles those observed in both mammalian and fish renal BBM.

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A novel neuroprotective role of a small peptide from flesh fly, 5-S-GAD in the rat retina in vivo

Brain Research ◽

10.1016/j.brainres.2008.09.021 ◽

2008 ◽

Vol 1240 ◽

pp. 196-203 ◽

Cited By ~ 11

Author(s):

Yoshiki Koriyama ◽

Hideji Tanii ◽

Mamoru Ohno ◽

Takahito Kimura ◽

Satoru Kato

Keyword(s):

Small Peptide ◽

Flesh Fly ◽

Rat Retina

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The cholecystokinin system in the rat retina: receptor expression and in vivo activation of tyrosine phosphorylation pathways

Neuropeptides ◽

10.1016/j.npep.2003.10.004 ◽

2003 ◽

Vol 37 (6) ◽

pp. 374-380 ◽

Cited By ~ 6

Author(s):

Maria J. Bragado ◽

Julio Perez-Marquez ◽

Luis J. Garcia-Marin

Keyword(s):

Tyrosine Phosphorylation ◽

Receptor Expression ◽

Rat Retina

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Functional characterization and chromosomal localization of a cloned taurine transporter from human placenta

Biochemical Journal ◽

10.1042/bj3000893 ◽

1994 ◽

Vol 300 (3) ◽

pp. 893-900 ◽

Cited By ~ 138

Author(s):

S Ramamoorthy ◽

F H Leibach ◽

V B Mahesh ◽

H Han ◽

T Yang-Feng ◽

...

Keyword(s):

Pigment Epithelium ◽

Retinal Pigment ◽

Functional Characterization ◽

Transport Activity ◽

Coding Region ◽

Taurine Transporter ◽

Taurine Transport ◽

Beta Alanine ◽

Acid Protein ◽

Human Chromosome 3

A cDNA clone highly related to the rat brain taurine transporter has been isolated from a human placental cDNA library. Transfection of this cDNA into HeLa cells results in a marked elevation of taurine transport activity. The activity of the cDNA-induced transporter is dependent on the presence of Na+ as well as Cl-. The Na+/Cl-/taurine stoichiometry for the cloned transporter is 2:1:1. The transporter is specific for taurine and other beta-amino acids, including beta-alanine, and exhibits high affinity for taurine (Michaelis-Menten constant approximately 6 microM). The clone consists of a coding region 1863 bp long (including the termination codon), flanked by a 376 bp-long 5′ non-coding region and a 625 bp-long 3′ non-coding region. The nucleotide sequence of the coding region predicts a 620-amino acid protein with a calculated M(r) of 69,853. Northern-blot analysis of poly(A)+ RNA from several human tissues indicates a complex expression pattern differing across tissues. The principal transcript, 6.9 kb in size, is expressed abundantly in placenta and skeletal muscle, at intermediate levels in heart, brain, lung, kidney and pancreas and at low levels in liver. Cultured human cell lines derived from placenta (JAR and BeWo), intestine (HT-29), cervix (HeLa) and retinal pigment epithelium (HRPE), which are known to possess Na(+)- and Cl(-)-coupled taurine transport activity, also contain the 6.9 kb transcript. Somatic cell hybrid and in situ hybridization studies indicate that the cloned taurine transporter is localized to human chromosome 3 p24-->p26.

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