scholarly journals Immunolocalization of band 3 protein in normal and cystic fibrosis skin.

1986 ◽  
Vol 34 (6) ◽  
pp. 823-826 ◽  
Author(s):  
D J Hazen-Martin ◽  
G Pasternack ◽  
S S Spicer ◽  
D A Sens
Keyword(s):  
Cystic Fibrosis ◽  
Membrane Protein ◽  
Chloride Transport ◽  
Duct Cell ◽  
Band 3 ◽  
Current Evidence ◽  
Band 3 Protein ◽  
Sweat Duct ◽  
Protein Immunoreactivity ◽  
Secretory Coil

Current evidence indicates that the defect in cystic fibrosis (CF) involves chloride transport in various epithelial cells. The sweat gland, one site of altered chloride transport in CF, was examined immunocytochemically for localization of a chloride-channel membrane protein, designated band 3 protein. Immunoreactivity was observed in sweat duct cell membranes of both normal and CF samples, whereas secretory coil regions were entirely unreactive. No difference was observed in the pattern or intensity of immunoreactivity between the two groups at the light microscopic (LM) level of resolution.

scholarly journals Cytosolic protein binding to band-3 protein inhibits endocytosis of isolated human erythrocyte membranes

1982 ◽  
Vol 207 (3) ◽  
pp. 595-598 ◽  
Author(s):  
K A Cordes ◽  
J M Salhany
Keyword(s):  
Membrane Protein ◽  
Integral Membrane Protein ◽  
Band 3 ◽  
Erythrocyte Membranes ◽  
Band 3 Protein ◽  
High Affinity ◽  
Human Erythrocyte Membranes ◽  
Affinity Interaction ◽  
Cytoplasmic Side

Recent studies of haemoglobin binding to the cytoplasmic side of the erythrocyte membrane have shown that the predominant high-affinity interaction occurs with the major integral membrane protein known as band-3 protein and that this interaction may occur within the intact erythrocyte in a manner regulated by cell pH. We report here that haemoglobin and glyceraldehyde 3-phosphate dehydrogenase binding to band-3 protein in isolated membranes can inhibit endocytosis during vesiculation in vitro. The specificity of this effect was demonstrated by showing that myoglobin, which has an affinity for the membrane fully one to two orders of magnitude lower than that for haemoglobin, does not inhibit endocytosis.

scholarly journals Immunocytochemistry of Band 3 Protein in Kidney and Other Tissues of Control and Cystic Fibrosis Patients

1987 ◽  
Vol 21 (3) ◽  
pp. 235-237 ◽  
Author(s):  
D J Hazen-Martin ◽  
G Pasternack ◽  
R A Hennigar ◽  
S S Spicer ◽  
D A Sens
Keyword(s):  
Cystic Fibrosis ◽  
Band 3 ◽  
Band 3 Protein

Comparison of the Action of an Organophosphorus Insecticide and Its Metabolite on Chloride and Sulfate Transport in Erythrocyte Membrane

1996 ◽  
Vol 51 (3-4) ◽  
pp. 226-232 ◽  
Keyword(s):  
Erythrocyte Membrane ◽  
Chloride Transport ◽  
Band 3 ◽  
Anion Transport ◽  
Time Dependent ◽  
Radioactive Isotopes ◽  
Organophosphorus Insecticide ◽  
Dependent Manner ◽  
Band 3 Protein ◽  
Equilibrium Exchange

Abstract Anion Transport, Erythrocyte Membrane. Organophosphorus Insecticides, Methylparathion, Pesticides The effect of the organophosphorus insecticide methylparathion and its main metabolite methylparaoxon on chloride and sulfate equilibrium exchange in pig erythrocytes was investi­ gated using an isotope labelling technique. Efflux of both radioactive isotopes with time follow ed a single exponential. Methylparathion and methylparaoxon inhibited the chloride equilibrium exchange in erythrocyte ghosts in a dose-and time-dependent manner. There was no difference between effects evoked by these two compounds. Methylparathion and methylparaoxon inhibited sulfate efflux from resealed ghosts. The effect was also dose-and time-dependent. Again, there was no difference between the action of both agents. Dixon analysis revealed a non-competitive character of the inhibition of the exchange of both anions with apparent Ki values 183 and 184 μᴍ for methylparathion and methylparaoxon, respec­tively in the case of chloride transport; for sulfate exchange these values were 675 and 648 μᴍ. It was suggested that structural similarity between the parent agent and its metabolite accounts for their identical effects. Methylparathion and methylparaoxon might inhibit the anion exchange indirectly by changing the fluidity of the erythrocyte membrane or directly by binding to the band 3 protein and evoking conformational changes that lead to the inhibi­tion of the anion transport. The insecticides, due to their ability to phosphorylate, might also disturb some regulation processes in the band 3 protein and affect anion transport in this way.

Reversed anion selectivity in cultured cystic fibrosis sweat duct cells

1992 ◽  
Vol 262 (1) ◽  
pp. C32-C38 ◽  
Author(s):  
C. L. Bell ◽  
M. M. Reddy ◽  
P. M. Quinton
Keyword(s):  
Cystic Fibrosis ◽  
Cultured Cells ◽  
Duct Cell ◽  
Normal Subjects ◽  
Sweat Duct ◽  
Human Genetic Disease ◽  
Normal Cells ◽  
Anion Selectivity ◽  
Cl Channels ◽  
Cl Conductance

The human genetic disease cystic fibrosis (CF) is characterized by defective epithelial Cl- conductance (GCl). To distinguish the CF-affected GCl from other Cl- channels, we have studied the properties of GCl in normal and CF cells grown from explanted reabsorptive sweat ducts (RD). The cultured cells from normal subjects retained some of the typical duct cell properties. The Na+ conductance inhibitor amiloride hyperpolarized intracellular potentials (Vm) by 10.4 +/- 1.6 mV (n = 12). Substitution of gluconate for Cl- depolarized Vm by 15.5 +/- 1.1 mV (n = 33). The apparent GCl (G'Cl) of normal cells was sensitive to adenosine 3',5'-cyclic monophosphate (forskolin, 10(-6) M), as evidenced by a significant increase (63%, n = 9) in the Cl- gradient induced depolarization, and more selective for Cl- than I- (substitution of Cl- by I- depolarized Vm by 6.3 +/- 0.3 mV, n = 49). Although the cells from CF subjects were statistically indistinguishable from normal cells based on Vm (-18.5 +/- 1.2 mV, n = 49 vs. -20.1 +/- 1.8 mV, n = 28), CF cells expressed differences in G'Cl, responses to forskolin, and anion selectivity. CF cells had a significantly reduced G'Cl as indicated by blunted responses to imposed Cl- gradients (26% of normal, n = 28). In contrast to our observations in normal cells, the G'Cl of CF cells was insensitive to forskolin.(ABSTRACT TRUNCATED AT 250 WORDS)

Freeze-Fracture Examination of Tight Junctions of Human Eccrine Sweat Glands

1980 ◽  
Vol 38 ◽  
pp. 634-635
Author(s):  
J. V. Briggman ◽  
J. Bigelow ◽  
H. Bank ◽  
S. S. Spicer
Keyword(s):  
Cystic Fibrosis ◽  
Freeze Fracture ◽  
Sweat Glands ◽  
Hypertonic Solution ◽  
Dark Cells ◽  
Clear Cells ◽  
Junctional Complexes ◽  
Secretory Coil ◽  
Eccrine Sweat Glands ◽  
Eccrine Sweat

The prevalence of strands shown by freeze-fracture in the zonula occludens of junctional complexes is thought to correspond closely with the transepi-thelial electrical resistance and with the tightness of the junction and its obstruction to paracellular flow.1 The complexity of the network of junc¬tional complex strands does not appear invariably related to the degree of tightness of the junction, however, as rabbit ileal junctions have a complex network of strands and are permeable to lanthanum. In human eccrine sweat glands the extent of paracellular relative to transcellular flow remains unknown, both for secretion of the isotonic precursor fluid by the coil and for resorption of a hypertonic solution by the duct. The studies reported here undertook, therefore, to determine with the freeze-fracture technique the complexity of the network of ridges in the junctional complexes between cells in the secretory coil and the sweat ducts. Glands from a patient with cystic fibrosis were also examined because an alteration in junctional strands could underlie the decreased Na+ resorption by sweat ducts in this disease. Freeze-fracture replicas were prepared by standard procedures on isolated coil and duct segments of human sweat glands. Junctional complexes between clear cells, between dark cells and between clear and dark cells on the main lumen, and between clear cells on intercellular canaliculi of the coil con¬tained abundant anastomosing closely spaced strands averaging 6.4 + 0.7 (mean + SE) and 9.0 +0.5 (Fig. 1) per complex, respectively. Thus, the junctions in the intercellular canaliculi of the coil appeared comparable in complexity to those of tight epithlia. Occasional junctions exhibited, in addition, 2 to 5 widely spaced anastomosing strands in a very close network basal to the compact network. The fewer junctional complexes observed thus far between the superficial duct cells consisted on the average of 6 strands arranged in a close network and 1 to 4 underlying strands that lay widely separated from one another (Fig. 2). The duct epitelium would, thus, be judged slightly more "leaky" than the coil. Infrequent junctional complexes observed to date in the secretory coil segment of a cystic fibrosis specimen disclosed rela¬tively few closely crowded strands.

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