Path of osmotic water flow through rabbit gall bladder epithelium

Os, C.H. van; Slegers, J. F. G.

doi:10.1016/0005-2736(73)90412-4

Cited by 37 publications

(20 citation statements)

References 37 publications

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“…First, in both the gallbladder 4 4 The permeability of the gallbladder to water reported here and by Moreno 5 is about 5 times less than that obtained previously by Van Os and Slegers (1973). Our unstirred layer correction only increases PH2o by a factor of 1.3 whereas that used by Van Os and Slegers increases Pn2o by a factor of 10.…”

Section: Large Polar Solutescontrasting

confidence: 71%

Routes of nonelectrolyte permeation across epithelial membranes

1974

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Summary. Radioactive tracer techniques were used to study the permeability of three epithelial membranes, the toad urinary bladder, frog choroid plexus, and rabbit gallbladder, to 16 nonelectrolytes. The general patterns of nonelectrolyte permeation were similar for all three membranes, and similar to those in other biological membranes. The permeability of lipophilic solutes was roughly proportional to their bulk phase oilJwater partition coefficients, but the slope was greater in the toad Nadder than in the gallbladder and plexus. Branched nonelectrolytes were Iess permeable than their straight-chain isomers in both the urinary bladder and gallbladder, but not in the choroid plexus. Small polar solutes permeated more rapidly than expected, and in the urinary bladder and gallbladder the permeation of urea and acetamide, but not water was inhibited by phloretin. This agent also increased 1,7-heptanediol permeability in the urinary bladder but in the gallbladder there was a marked inhibition. In all three epithelia a separate pathway exists for the permeation of large polar solutes, but quantitatively this is least important in the toad bladder. It is concluded that variations in passive nonelectrolyte permeation across epithelia are due to (i) variations in the composition and configuration of membrane lipids, (ii) the presence or absence of pathways for small solutes, and (iii) the absence or presence of pathways for larger polar solutes.We also conclude that there are at least two effects of phloretin on the permeation of nonelectrolytes across biological membranes, and that there are variations in each effect from one membrane to another.Simple epithelial membranes, such as those of the intestine, gallbladder, choroid plexus, renal tubule, and toad urinary bladder, are composed of a sheet of cells held together at the apical surface by tight junctions (zonula occludens). These junctions are formed by the fusion of the plasma membranes of adjacent cells completely around the perimeter of each cell (see

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Section: Large Polar Solutescontrasting

confidence: 71%

Routes of nonelectrolyte permeation across epithelial membranes

1974

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“…This issue was not tested rigorously in the present experiments , since, for the reasons indicated previously, permeation coefficients were measured only at two temperatures. However, a similar assumption has been made by Hays et al [-22] in evaluating the effect of ADH on the EA for water diffusion in toad urinary bladder; and, both in frog skin [18] and in rabbit gall bladder [51], water permeation appears to follow a linear Arrhenius relationship for the temperature range 21-39 ~ Given this caveat, Tables 2 and 3 summarize the results for simultaneous measurements of the apparent activation energies for water and n-butyr- amide permeation. In the absence of ADH (Table 2), E A was 9.35_+0.92 and 19.40 _+ 1.6 kcal per mole for, respectively, Py and n-butyramide permeation; the mean paired difference between these two values was 7.7 + 0.74 (P < 0.002).…”

Section: Apparent Activation Energies For Water and Solute Permeationmentioning

confidence: 63%

Effect of antidiuretic hormone on water and solute permeation, and the activation energies for these processes, in mammalian cortical collecting tubules

et al. 1977

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Summary. The present studies were designed to assess the ways in which antidiuretic hormone (ADH) alters water and solute permeation across isolated, rabbit cortical collecting tubules. In earlier work, it was observed: that ADH produced a tenfold increment in P/(cm per sec), the osmotic water permeability coefficient, and a fourfold increment in PD~ (cm per sec), the diffusional water permeability coefficient; that small hydrophilic solutes such as urea, thiourea and acetamide (each having oil/water partition coefficients __< 0.0008) had vanishingly low permeation coefficients and unity reflection coefficients, even in the presence of ADH; that lumen to bath osmosis involved a transcellular route; and, that the disparity between Ps and Po~, either with or without ADH, could be rationalized in terms of cellular diffusion constraints, i.e., that water transport across luminal membranes was diffusionat.The present experiments evaluated the effects of ADH on diffusion of moderately lipophilic solutes (e.g., butyramide, isobutyramide, and antipyrine, each solute having an oil/water partition > 0.0008) across luminal membranes of rabbit cortical collecting tubules, and the effects of ADH on the apparent activation energies (EA, kcal per mole) for water and solute permeation across these tubules. Three major results were obtained: (1) ADH produced a 60-100 ~ increase in the permeation rates for these solutes. (2) The ADH-dependent apparent E A for water permeation was 9.35_+0.92 kcal per mole, and the ADH-dependent apparent E A for permeation of moderately lipophilic solutes was in the range 15.8-19.6 kcal per mole. (3) The ADH-independent E A values for these transport processes were statistically indistinguishable from the ADH-dependent E A values.When viewed in the context of transport mechanisms for water and solute permeation across synthetic lipid bilayer membrane systems, these results are consistent with the possibility that diffusion of water and moderately lipophilic solutes across mammalian collecting tubules may involve parallel sites in luminal plasma membranes: routes for water diffusion

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“…It is also possible that in the perfused segments, water could have been transported through epithelial cells and membranes, especially when perfusion fluid osmolality was high (500 and 700 mosmol/kg). In the gall bladder, osmotic water flow into the lumen has been proposed to proceed mainly through the epithelial cells and cell membranes, rather than through intercellular spaces and tight junctions (23,25). In the present study of young growing rats and in previous studies of adult rats (5,26), mannitol (with an estimated molecular radius of 4.0 A) and phenol red did not cross the mucosal membrane of either jejunum or ileum in significant amounts ( Table I), suggesting that the permeability of the mucosal membrane to mannitol and phenol red was not markedly different in the intestine of the 2-, 3-, and 7-wk-old rats, and the equivalent "pore" radius of the intestinal epithelium (cell membrane and shunt pathways) were probably not greater than 4 A reported for adult rats (27)(28)(29)(30).…”

Section: Discussionmentioning

confidence: 99%

Maturation of Jejunum and Ileum in Rats

Younoszai¹,

Sapario²,

Laughlin³

1978

J. Clin. Invest.

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A B S T R A C T During osmotic diarrhea, loss of water and electrolytes appears to be greater in infants than in adults. In 2-, 3-, and 7-wk-old rats, we studied net transport of H20, Na, and Cl, during in vivo perfusion of segments of the jejunum and ileum, from solutions with osmolalities of 300, 375, 500, or 700 mosmol/kg. In the jejunal segments, from the hypertonic solutions net transport of H20, Na, and Cl was into the lumen and greater in the 2-than 7-wk-old rats. In the ileal segments, transport of water was into the lumen, transport of Na was minimal and variable, whereas transport of Cl was usually out of the lumen. In 3-wk-old rats, transport rates were intermediate between those in 2-and 7-wk-old rats. The calculated filtration coefficient (microliters of H20 transported per hour per unit osmolality gradient-lumen-serum -per gram dry weight) of water suggested that the resistance to water flow did not increase with rise in luminal hypertonicity in the jejunum of the 2-and 3-wk-old rats, whereas in jejunum of the 7-wk-old rats and in ileum of rats in all three ages, the resistance to water flow increased with the rise in luminal osmolality. The differences in the transport rates and the resistance to water flow, between segments of the 2-, 3-, and 7-wk-old rats, suggested a maturational phenomenon that appears to continue beyond the 3rd wk of life and could have been due to differences in some physical property of the mucosal membrane.

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Path of osmotic water flow through rabbit gall bladder epithelium

Cited by 37 publications

References 37 publications

Routes of nonelectrolyte permeation across epithelial membranes

Routes of nonelectrolyte permeation across epithelial membranes

Effect of antidiuretic hormone on water and solute permeation, and the activation energies for these processes, in mammalian cortical collecting tubules

Maturation of Jejunum and Ileum in Rats

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