Properties of Water Channels in Human Red Cells

Macey, Robert I.; Karan, Daniel M.; Farmer, Robert E.L.

doi:10.1007/978-1-4684-0961-1_22

Cited by 42 publications

(44 citation statements)

References 11 publications

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“…Urea shows no saturation kinetics (Fig.3) and well-established inhibitors of water and urea transport in other RBC with UT-B and AQP1 (Table6) inhibit neither P urea nor P d . The E A of P urea is high, 71.2kJmol -1 , and of the same magnitude as other nonelectrolytes that permeate the lipid membrane phase (Wartiovaara, 1949;Macey et al, 1972;Galey et al, 1973;Brahm, 1983a). E A of P d is 41.9kJmol -1 .…”

Section: Do Urea and Water Share A Pathway In Common In Rbc?mentioning

confidence: 86%

The permeability of red blood cells to chloride, urea, and water

Brahm

2013

Journal of Experimental Biology

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SUMMARYThis study extends permeability (P) data on chloride, urea and water in red blood cells (RBC), and concludes that the urea transporter (UT-B) does not transport water. cms -1 (human). DIDS, DNDS and phloretin inhibit P Cl by >99% in all RBC species. PCMBS, PCMB and phloretin inhibit P urea by >99% in Amphiuma, dog and human RBC, but not in chick and duck RBC. PCMBS and PCMB inhibit P d in duck, dog and human RBC, but not in chick and Amphiuma RBC. Temperature dependence, as measured by apparent activation energy, E A , of P Cl is 117.8 (duck), 74.9 (Amphiuma) and 89.6kJmol −1 (dog). The E A of P urea is 69.6 (duck) and 53.3kJmol −1 (Amphiuma), and that of P d is 34.9 (duck) and 32.1kJmol −1 (Amphiuma). The present and previous RBC studies indicate that anion (AE1), urea (UT-B) and water (AQP1) transporters only transport chloride (all species), water (duck, dog, human) and urea (Amphiuma, dog, human), respectively. Water does not share UT-B with urea, and the solute transport is not coupled under physiological conditions.

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Section: Do Urea and Water Share A Pathway In Common In Rbc?mentioning

confidence: 86%

The permeability of red blood cells to chloride, urea, and water

Brahm

2013

Journal of Experimental Biology

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“…The first studies on water transport started in the late fifties on mammalian erythrocytes [3,4]. Evidence for the existence of water channels was based mainly on measures of high osmotic water permeability (inhibited by mercurials) [4,5], on low activation energy for transport [6] and on the ratio of osmotic to diffusion water permeabilities [7].…”

Section: Introductionmentioning

confidence: 99%

“…Evidence for the existence of water channels was based mainly on measures of high osmotic water permeability (inhibited by mercurials) [4,5], on low activation energy for transport [6] and on the ratio of osmotic to diffusion water permeabilities [7]. Only in the nineties the first water channel protein known now as aquaporin 1 (AQP1) was identified in erythrocytes [8] and nowadays many other aquaporins have been recognized in nearly all-living organisms [9].…”

Section: Introductionmentioning

confidence: 99%

Lack of Aquaporin 3 in bovine erythrocyte membranes correlates with low glycerol permeation

Campos

Moura

Oliva

et al. 2011

Biochemical and Biophysical Research Communications

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In general, erythrocytes are highly permeable to water, urea and glycerol.However, expression of aquaporin isoforms in erythrocytes appears to be species characteristic. In the present study, human (hRBC) and bovine (bRBC) erythrocytes were chosen for comparative studies due to their significant difference in membrane glycerol permeability.Osmotic water permeability (P f ) at 23 ºC was (2.89 0.37) 10 -2 and (5.12 0.61) 10 -2 cm s -1 for human and bovine cells respectively, with similar activation energies for water transport. Glycerol permeability (P gly ) for human ((1.37 0.26) 10 -5 cm s -1 ) differed in three orders of magnitude from bovine erythrocytes ((5.82 0.37) 10 -8 cm s -1 ) that also showed higher activation energy for glycerol transport.When compared to human, bovine erythrocytes showed a similar expression pattern of AQP1 glycosylated forms on immunoblot analysis, though in slight higher levels, which could be correlated with the 1.5-fold larger P f found. However, AQP3 expression was not detectable. Immunofluorescence analysis confirmed the absence of AQP3 expression in bovine erythrocyte membranes.In conclusion, lack of AQP3 in bovine erythrocytes points to the lipid pathway as responsible for glycerol permeation and explains the low glycerol permeability and high E a for transport observed in ruminants.

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“…The first experimental evidence for the existence of water channels in cell membranes was obtained for red blood cells (Farmer & Macey, 1970;Macey et al, 1972;Paganelli & Solomon, 1957;Vieira et al, 1970) and renal epithelia (Verkman, 1992), and was based mainly on measures of high osmotic water permeability (inhibited by mercurial reagents) and of low activation energy for water transport.…”

Section: Introductionmentioning

confidence: 99%

Water channels are important for osmotic adjustments of yeast cells at low temperature

Soveral

Veiga²,

Loureiro-Dias

et al. 2006

Microbiology

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The importance of aquaporin expression in water permeability in Saccharomyces cerevisiae was assessed by measuring the osmotic water permeability coefficient (P f ) and the activation energies (E a ) from both hypo-and hypertonic experiments performed with whole protoplasts from four strains differing in aquaporin level of expression: parental, double-deleted and overexpressing AQY1 or AQY2. Double-deleted (lower P f ) and AQY1-overexpressing strains (higher P f ) presented linear Arrhenius plots with E a consistent with fluxes mainly through the lipids [16?3 kcal mol "1 (68?2 kJ mol )], respectively. The Arrhenius plots for the parental (swelling experiments) and overexpressing AQY2 strains (swelling and shrinking experiments) were not linear, presenting a break point with a change in slope around 23 6C. The E a values for these strains, calculated for temperatures ranging from 7 to 23 6C, were lower [9?5 kcal mol "1 (39?7 kJ mol The permeabilities for each strain relative to the deletion strain show that an increase in permeability due to the presence of aquaporins was more relevant at low temperatures. Following our results, we propose that water channels play an important role for osmotic adjustment of yeast cells at low temperature.

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Properties of Water Channels in Human Red Cells

Cited by 42 publications

References 11 publications

The permeability of red blood cells to chloride, urea, and water

The permeability of red blood cells to chloride, urea, and water

Lack of Aquaporin 3 in bovine erythrocyte membranes correlates with low glycerol permeation

Water channels are important for osmotic adjustments of yeast cells at low temperature

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