Renal sugar transport in the winter flounder: V. secretion of 2-deoxy-D-galactose

1978 ◽  
Vol 234 (5) ◽  
pp. F424-F431
Author(s):  
J. B. Pritchard ◽  
G. Booz ◽  
A. Kleinzeller
Keyword(s):  
Sugar Transport ◽  
Winter Flounder ◽  
Free Sugar ◽  
Renal Tubules ◽  
Pseudopleuronectes Americanus ◽  
Clearance Ratio ◽  
Renal Handling ◽  
Cell Clearance

Isolated renal tubules and renal clearance techniques were used to characterize the renal handling of 2-deoxy-D-galactose (2-d-Gal) by the winter flounder (Pseudopleuronectes americanus). In vitro, energy-dependent, pH-sensitive uptake of 2-d-Gal (2–100 micron) was seen at the antiluminal face of the cell. Clearance measurements showed net secretion of 2-d-Gal in vivo. The mean clearance of 2-d-Gal in 18 fish was 0.98 +/- 0.16 ml/h while the glomerular filtration rate (GFR) was only 0.37 +/- 0.10 ml/h. Secretion was associated with marked renal accumulation of both 2-d-Gal and phosphorylated derivatives (2-d-Gal-1-phosphate). Tissue-to-plasma ratios (T/P) averaged 19 for free sugar and 59 for total sugar. Both clearance ratio and T/P were reduced to approximately 1 by injection of galactose (2.5 mmol/kg) simultaneously with 2-d-Gal (25 mumol/kg). Phlorizin (2.5 mumol/kg) increased net 2-d-Gal secretion, whereas glucose (2.5 mmol/kg) produced no change in secretion. Both compounds depressed 2-d-Gal T/P. This result suggests the presence of readsorptive transport at the brush border, sensitive to glucose and phlorizin.

Renal sugar transport in the winter flounder. VI. Reabsorption of D-mannose

1982 ◽  
Vol 242 (4) ◽  
pp. F415-F422 ◽  
Author(s):  
J. B. Pritchard ◽  
G. W. Booz ◽  
A. Kleinzeller
Keyword(s):  
Plasma Concentrations ◽  
Sugar Transport ◽  
Winter Flounder ◽  
Pseudopleuronectes Americanus ◽  
Paralichthys Lethostigma ◽  
Southern Flounder ◽  
Cotransport System ◽  
Stimulation Experiments

The transport of D-mannose (Man) in flounder kidney was studied using renal clearance techniques in vivo and brush border membrane (BBM) vesicles in vitro. At plasma concentrations of 50-100 microM Man, the winter flounder (Pseudopleuronectes americanus) reabsorbed up to 70% of the filtered sugar. Man phosphates, but not free Man, accumulated in renal cells. Reabsorption of Man was reduced by phlorizin, D-glucose, methyl-alpha-D-glucoside, methyl-alpha-D-mannoside, and 2-deoxy-D-glucose. In BBM vesicles a Na+-dependent, phlorizin-sensitive overshoot in Man uptake (10 microM) was seen. Na+-dependent Man uptake was saturable, with an apparent Km of 127 microM. The transport properties for Man were identical in BBM vesicles from the winter flounder and southern flounder (Paralichthys lethostigma). The transport specificity was determined by cis-inhibition and trans-stimulation experiments with BBM. Glucose, galactose, 1,5-anhydro-D-mannitol (i.e., 1-deoxymannose), 2-deoxy-2-fluoro-D-glucose, and methyl-alpha-mannoside were shown to share the carrier-mediating mannose transport. 2-Deoxyglucose, methyl-alpha-2-deoxy-D-glucoside, and both the isomers (alpha and beta) of methyl-D-glucoside did not. In contrast, alpha-methyl-D-glucoside inhibited D-glucose transport both in vivo and in BBM vesicles. It is concluded that Man reabsorption in the flounder occurs via a Na+-cotransport system that also handles glucose but that differs from the glucose/methyl-alpha-D-glucoside reabsorptive pathway in that 1) an oxygen on C-1 is not required, and 2) an axial configuration for -OH on C-2 (C1 conformation) is readily accommodated.

Renal sugar transport in the winter flounder. I. Renal clearance studies

1976 ◽  
Vol 231 (2) ◽  
pp. 603-607 ◽  
Author(s):  
JB Pritchard ◽  
A Kleinzeller
Keyword(s):  
Renal Tubule ◽  
Sugar Transport ◽  
Renal Tissue ◽  
Total Sugar ◽  
Winter Flounder ◽  
Free Sugar ◽  
Pseudopleuronectes Americanus ◽  
Renal Handling ◽  
Luminal Membrane ◽  
Clearance Studies

The renal handling of several sugars was examined using clearance techniques in the winter flounder Pseudopleuronectes americanus. The nonmetabolizable sugar alpha-methyl-D-glucoside was extensively reabsorbed, with consequent accumulation in renal tissue to nearly twice plasma concentration. Both glucose and phlorizin abolished reabsorption and reduced tissue-to-plasma ratios (T/P). D-Galactose was reabsorbed. However, the T/P for free galactose was only 0.6 (total sugar was 1.7). Glucose and phlorizin produced only a transient decrease in reabsorption and no change in T/P. 2-Deoxy-D-glucose showed neither net reabsorption nore secretion. Nevertheless, kidney T/P were inexcess of 6 for total sugar and 1.2 for free sugar, indicating entry through the peritubular face of the tubule. Neither glucose nor phlorizin altered 2-deoxy-D-glucose clearance, but both reduced T/P for total sugar (2.4) and free sugar (0.7). Thus, several systems govern the handling of these sugars at the luminal membrane of the renal tubule, just as has been previously demonstrated at the peritubular membrane in this species.

Renal sugar transport in the winter flounder. II. Galactose transport system

1976 ◽  
Vol 231 (2) ◽  
pp. 608-613 ◽  
Author(s):  
A Kleinzeller ◽  
GR Dubyak ◽  
JM Mullin
Keyword(s):  
Sugar Transport ◽  
Basal Membrane ◽  
Ring Structure ◽  
Close Packing ◽  
Winter Flounder ◽  
Sugar Uptake ◽  
Renal Tubules ◽  
Pseudopleuronectes Americanus ◽  
Galactose Transport ◽  
Hexose Carrier

The structural specificity of the transport of 0.5 mM D-galactose and 2-deoxy-D-galactose by teased renal tubules of the winter flounder Pseudopleuronectes americanus was investigated. The sugar uptake reflects preponderantly transport at the antiluminal membrane of tubular cells. Both sugars compete for the transport sites, indicating the sharing of a common carrier. 1) The structural requirements for the hexose-carrier interaction were defined by an inhibiton analysis using 12 structurally analogous sugars (5 mM): a (pyranose) ring structure; a free hydroxyl on C1; free hydroxyls (equatorial configuration) on C3 and C4; an oxygen on C6. Close packing in the vicinity of C2 is indicated. 2) Consonant with the requirement of a free C1-OH, beta-methyl-D-galactoside is not transported 3) Increasing concentrations (0.05-0.5 mM) of phlorizin and phloretin inhibit sugar uptake by lowering cellular levels of phosphorylated hexoses, whereas the levels of free sugars are not depressed. The possibility of an interaction of the sugar at C1-0H with a phosphorylated group at the carrier as the first step in the translocation process of both hexoses across the basal membrane is raised.

Melanophore β-adrenoceptors in patterning in a flatfish, Pseudopleuronectes americanus

2007 ◽  
Vol 85 (6) ◽  
pp. 695-702 ◽  
Author(s):  
D. Burton
Keyword(s):  
Salt Solution ◽  
Winter Flounder ◽  
Dark Band ◽  
Pigment Dispersion ◽  
In Vitro Experiments ◽  
Pseudopleuronectes Americanus ◽  
Adrenoceptor Agonists

In vitro experiments were performed on melanophores bourne on scale slips sampled from three major areas (general background, dark band, and white spot) of the integumentary pattern of winter flounder, Pseudopleuronectes americanus (Walbaum, 1792). The effects of the respective β1- and β2-adrenoceptor agonists dobutamine and terbutaline and antagonists atenolol and ICI 118551 on pattern-related melanosome aggregation in response to exogenously applied L-noradrenaline were determined, as well as their effects on melanosome dispersion in balanced salt solution. The results demonstrate β1-adrenoceptor mediation in flatfish melanosome dispersion, with pattern-related variation, and also provide further evidence for β2-subtype involvement. Based on mammalian physiology, two β-subtypes will facilitate melanophore responsiveness to both neural and circulatory catecholamines. The in vivo role of these β-subtypes is discussed in relation to previously described attributes of the patterning behaviour of this species, which incorporates balances between α- and β-adrenoceptors. Dark band melanophores display a β-adrenoceptor bias, in contrast with other areas of the pattern, which would be consistent with their capacity for pigment dispersion in stressed flounders and with the slow paling of these bands during background-related responses.

Sugar absorption and secretion by winter flounder intestine

1981 ◽  
Vol 240 (5) ◽  
pp. G392-G400
Author(s):  
R. J. Naftalin ◽  
A. Kleinzeller
Keyword(s):  
Sugar Transport ◽  
Winter Flounder ◽  
Transport Systems ◽  
Secretory Process ◽  
Free Sugar ◽  
Pseudopleuronectes Americanus ◽  
Experimental Conditions ◽  
Sugar Absorption ◽  
Net Flux ◽  
Secretory System

Transport of sugars by winter flounder (Pseudopleuronectes americanus) intestine has been examined, and the following observations have been made. 1) No net absorption of D-galactose was found in controls; however, mucosally applied 0.1 mM phlorizin stimulated the mucosal-serosal flux with net sugar secretion. 2) Net absorption of methyl glycosides was inhibited by D-galactose, 0.1 mM ouabain, and phlorizin (without induction of secretion). 3) Net secretion of 2-deoxy-D-galactose was found without cellular accumulation of free sugar. The secretory process had a Km of 10 mM and was inhibited by serosally applied 0.1 mM phloretin, bilateral replacement of Ringer Na+ by choline, serosal ouabain, and D-galactose. 4) No net absorption or secretion of 2-deoxy-D-glucose was found with a variety of experimental conditions. 5) At least two active transport systems for sugars appear to be operative in the flounder intestine: a conventional Na+-dependent sugar transport system across the brush border that allows net absorption and a Na+-dependent secretory system that apparently also operates across the mucosal border. Because D-galactose is transported by both systems, there is no net flux of this sugar. Several possible models for the net secretory system are discussed.

Renal handling of the polar DDT metabolite DDA (2,2-bis[p-chlorophenyl] acetic acid) by marine fish

1977 ◽  
Vol 233 (2) ◽  
pp. F126-F132
Author(s):  
J. B. Pritchard ◽  
K. J. Karnaky ◽  
A. M. Guarino ◽  
W. B. Kinter
Keyword(s):  
Acetic Acid ◽  
Water Solubility ◽  
Metabolic Inhibitors ◽  
Pseudopleuronectes Americanus ◽  
Renal Handling ◽  
Chlorophenol Red ◽  
Tubular Lumen ◽  
Uptake Studies

The renal handling of 2,2-bis(p-chlorophenyl) acetic acid (DDA) was examined in the isolated tubules of the winter flounder (Pseudopleuronectes americanus) in vitro in conjunction with clearance studies in the flounder and in the aglomerular goosefish (Lophius americanus). In vitro, both uptake studies and autoradiography showed extensive energy-dependent accumulation within the cytoplasm of tubular cells and the tubular lumen. The uptake was strongly inhibited by p-aminohippurate and chlorophenol red. A second component of uptake was insensitive to metabolic inhibitors or organic acids and represented tissue binding. In vivo, both species showed net secretion which was inhibited by probenecid. Comparison of DDT and DDA distribution and excretion emphasized the importance of the greater water solubility of DDA and of its secretory transport, since DDA was excreted at over 200 times the rate of DDT. Liver, kidney, and bile also showed elevated DDA tissue-to-plasma ratios. Thus, the organic acid system mediates the accumulation and excretion of DDA in these fish.

Induction of Winter Flounder Antifreeze Protein Messenger RNA at 4 C in vivo and in vitro

1986 ◽  
Vol 59 (6) ◽  
pp. 679-695 ◽  
Author(s):  
Jeffrey L. Price ◽  
Brian B. Gourlie ◽  
Yuan Lin ◽  
Ru Chih C. Huang
Keyword(s):  
Messenger Rna ◽  
Antifreeze Protein ◽  
Winter Flounder

Experimental Cystinuria: the Cycloleucine Model. I. Amino Acid Interactions in Renal and Intestinal Epithelia

1975 ◽  
Vol 53 (6) ◽  
pp. 1027-1036 ◽  
Author(s):  
André G. Craan ◽  
Michel Bergeron
Keyword(s):  
Amino Acids ◽  
Renal Tubules ◽  
Intestinal Epithelia ◽  
Luminal Membrane ◽  
Luminal Side ◽  
Convoluted Tubules ◽  
Dibasic Amino Acids ◽  
Everted Sacs

The injection of cycloleucine (1-aminocyclopentanecarboxylic acid (ACPC)) into rats produces a hyperexcretion of dibasic amino acids and cystine, an aberration resembling cystinuria. This may constitute a model of experimental cystinuria, and the transport of amino acids involved in this disease was studied with the techniques of everted intestinal sacs (in vitro) and microinjections into renal tubules (in vivo). In everted sacs from normal rats, there was a decrease in transfer and in accumulation of L-cystine (0.03 mM), L-lysine (0.065 mM) and L-valine (0.065 mM) when ACPC was on the mucosal (luminal) side. Dibasic amino acids such as L-ariginine and L-lysine caused a similar inhibition of the transport of L-cystine. However, when ACPC was on the serosal (antiluminal) side, a lesser effect was noted while arginine and lysine had no effect. Intestinal sacs from treated rats (ACPC, 300 mg/kg × 3 days) transferred and accumulated as much L-cystine as those from control rats. The interaction between cycloleucine and L-cystine was competitive at the luminal and non-competitive at the antiluminal side of the intestine. Cycloleucine inhibited L-lysine transport in a non-competitive fashion at either side of the intestine. L-Lysine also interacted in a non-competitive fashion with L-cystine transport at the luminal membrane. In proximal convoluted tubules, the presence of L-arginine or ACPC caused a decrease in the transport of L-cystine and L-lysine. L-Valine exerted no effect. Furthermore, L-lysine and ACPC did not impair the reabsorption of L-valine significantly.These results suggest a functional heterogeneity between luminal and antiluminal membranes of renal and intestinal epithelia and the existence, at both membranes, of different transport sites for cystine and dibasic amino acids.

scholarly journals Differential in vivo Sensitivity of Melanophores and Xanthophores to Catecholamines in Winter Flounder (Pseudopleuronectes Americanus Walbaum) Integumentary Patterns

1985 ◽  
Vol 114 (1) ◽  
pp. 649-659
Author(s):  
D. Burton
Keyword(s):  
Winter Flounder ◽  
Pseudopleuronectes Americanus ◽  
Adrenoceptor Antagonist ◽  
Adrenoceptor Agonist ◽  
Albedo Change ◽  
Differential Responses

The catecholamines, adrenalin, dopamine and noradrenalin induce differential aggregation of melanophores in black-adapted winter flounder, Pseudopleuronectes americanus, paralleling patterning responses to albedo change. These differential responses to catecholamines suggest that the patterning mechanism in this species is largely dependent on a balance between neural aggregating and dispersing elements. The α-adrenoceptor agonist phenylephrine evokes paling in all pattern components in blackadapted flounder, whilst the α-adrenoceptor antagonist phentolamine darkens white-adapted flounders. The α-adrenoceptor agonist isoproterenol and the α-adrenoceptor antagonist propranalol have no effect on chromatophores of white-adapted flounder, but induce pallor in blackadapted flounder, which is interpreted as non specific. Noradrenalin elicits patterning responses in chromatically decentralized flounder, although the duration of pallor is shorter. The xanthophores, which are dispersed by a pituitary factor, will aggregate in response to high catecholamine doses.

‘Facilitation’ of Melanophore Responses in Winter Flounder Pseudopleuronectes Americanus

1992 ◽  
Vol 168 (1) ◽  
pp. 289-299
Author(s):  
D. BURTON ◽  
M. P. O'DRISCOLL
Keyword(s):  
Response Rates ◽  
Winter Flounder ◽  
Repeated Injection ◽  
Pseudopleuronectes Americanus ◽  
Black And White ◽  
Skin Samples

Melanophores of winter flounder (Pseudopleuronectes americanus) subjected to repeated transfers between black and white backgrounds display pronounced enhancement of the rates of melanosome aggregation and dispersion. Melanosome aggregation in response to repeated injection of noradrenaline displays a similar enhancement. In vitro preparations of microscopic skin samples on scales removed during successive cycles of background changes also display increasing melanophore response rates to K+ stimulation. It is concluded that a physiological ‘priming’ mechanism is involved peripherally at the melanophore level and it is proposed that this represents a form of facilitation. Also, it is deduced from these experiments that a modulation of the microtubular channels associated with melanosome translocation is probably the basis of the facilitation process.

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