Heterogeneity of the β-amino-preferring transport system in rat kidney cortex. Differential influence of glutathione oxidation

Chesney, Russell W.; Jax, Diane K.

doi:10.1016/0005-2736(77)90210-3

Cited by 22 publications

(14 citation statements)

References 22 publications

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“…Thus, an examination of these conditions is germaine. In adult cortex, amino acid uptake was almost entirely dependent on aerobic metabolism; taurine accumulation also requ&ed aerobic metabolism (7)(8)(9). Concentrative uptake was not totally abolished by an aerobiosis in tissue from newborn animals.…”

Section: Speculationmentioning

confidence: 95%

“…Taurine accumulation by adult rat and mouse slices is sodiumdependent at both transport skes and only other /3-amino acids, of all amino acids examined, inhibited the uptake of taurine in a competitive fashion at both sites (7)(8)(9). Thus, an examination of these conditions is germaine.…”

Section: Speculationmentioning

confidence: 98%

“…Heterogeniety of taurine transport into adult Sprague-Dawley rat cortex slices was found (7,8). The first uptake system had an apparent Km of 0.1-0.2 mM and the second system values of 13-15 mM, akin to those concentrations found in the mouse (9).…”

Section: Speculationmentioning

confidence: 99%

“…Thin wrtex slices were prepared as previously described (7)(8)(9) and cortex slices were made from newborn and 2-week-old animals using only the surface of the kidney. By examination under a microscope, these slices contained only cortex cells.…”

Section: Preparation Of Tissuesmentioning

confidence: 99%

“…Slices were removed, blotted, weighed, boiled, and the supernate counted as described (7,8). The medium was altered in several ways for certain studies: choline or potassium choloride were substituted for NaCl in a stepwise fashion so as to maintain constant osmolality.…”

Section: Tissue Incubationmentioning

confidence: 99%

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Developmental Aspects of Renal β-Amino Acid Transport II. Ontogeny of Uptake and Efflux Processes and Effect of Anoxia

Chesney

Jax

1979

Pediatr Res

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SummaryRenal cortex slices from newborn, tweek, and 4-week-old Sprague-Dawley rats had reduced initial rates of taurine uptake compared io adult slices after short (< 30 min) incubation periods. From birth onward, steady-state accumulation occurred by at least two sodium-dependent uptake systems. The first system had an "apparent KmlW = 0.1 mM and a Vmax varying from 1.8 to 5.1 pmoles/ml ICF/120 min at four ages. The second uptake mode had an apparent Kmz = 12-16 mM and a Vmax of 45 pmoles/ml ICF/120 min. Emux of taurine was reduced in slices from younger animals possibly accounting for taurinuria. Only other p-amino acids inhibited accumulation.Anoxia inhibited uptake at high concentrations (> 1.0 mM) at each age, but taurine accumulation at low concentrations (< 0.4 mM) was relatively protected from anoxia in neonatal (< 36 hr of age) tissue. Preincubation in taurine-free medium for 120 min enhanced low concentration, but not high concentration uptake in neonatal and 2-week slices.After preincubation in dibutyryl cyclic AMP (dbcAMP) enhanced uptake of taurine was found in adult cortex, but not in neonatal cortex.The ontogeny of renal taurine transport in cortex slices a p peared to involve faster initial uptake rates and faster efflux as well as greater dependence on aerobic metabolism with maturation. Age-related differences in the response to preincubation and cyclic nucleotides were also indicative of maturational events in renal tubular amino acid transport. SpeculationTaurinuria found in the immature rat may involve decreased initial uptake rates and/or decreased efflux, but heterogeniety of transport processes across the antiluminal membrane was apparent at birth. Preincubation in taurine-free medium increased the rate of taurine accumulation by immature cortex, but changes in transport processes across the brush border membrane may account for the decrease in taurinuria found after the age of 2 weeks.

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Section: Speculationmentioning

confidence: 95%

Section: Speculationmentioning

confidence: 98%

Section: Speculationmentioning

confidence: 99%

Section: Preparation Of Tissuesmentioning

confidence: 99%

Section: Tissue Incubationmentioning

confidence: 99%

See 3 more Smart Citations

Developmental Aspects of Renal β-Amino Acid Transport II. Ontogeny of Uptake and Efflux Processes and Effect of Anoxia

Chesney

Jax

1979

Pediatr Res

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Taurine transport by isolated flounder renal tubules

1982

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Previous in vivo clearance studies (Schrock et al., '82) have revealed that taurine is secreted by marine fish kidneys. In the present study taurine secretion by the flounder (Pseudopleuronectes americanus) renal tubule was investigated by assaying the transport of 14C-taurine in vitro. Collections from isolated fluid-secreting flounder tubules confirmed the presence of a tubular mechanism for taurine secretion. The flounder renal tubule concentrated taurine in the lumen at a lumen/bath ratio of 25, with the movement across the peritubular membrane identified as the concentrating step of taurine transport. Studies with teased flounder renal tubules identified transport as Na+ and C1- dependent. Taurine transport was inhibited by beta alanine, gamma-aminobutyric acid, and hypotaurine. In a study of the hormonal control of taurine transport, only the adrenal steroid dexamethasone stimulated taurine uptake by the flounder renal tubules. Transport was not affected by the second messengers adenosine 3'5'-cyclic monophosphate, guanosine 3'5'-cyclic monophosphate, adenosine, or Ca++ ionophore (A12384).

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