Hypo- and hyperosmolal saline and raffinose on kidney cortical cell volume at 37 degrees C

Abstract

Cell water content was measured in respiring rat renal cortical slices incubated in hypo- and hyperosmolal saline with and without raffinose and ouabain for 60 min at 37 degrees C. At 60 min, hyposmolal saline (228 mosmol/kg H2O) caused a 16% swelling of cells, whereas addition of 73 mM raffinose (299 mosmol/kg H2O) caused a 33% shrinkage. Physiological saline plus raffinose (364 mosmol/kg H2O) caused a 28% cell shrinkage, whereas addition of saline (385 mosmol/kg H2O) produced only a 10% decrease in cell volume. The effects of raffinose were reversible. At physiological Na concentrations, osmole for osmole raffinose was 4 times as effective in shrinking cells as saline, but only 2 times as effective at Na of 112 mM. Osmotic effectiveness of saline changed, that of raffinose did not. Ouabain caused no changes in cell volume and did not prevent the effect of raffinose. In conclusion, there is no volume regulation to nonelectrolyte solutes and only partial volume regulation to saline, and this is due to differential osmotic effects of these solutes, that of saline decreasing from low to high Na.

Metabolic and ionic responses of trout hepatocytes to anisosmotic exposure

“…In contrast to hyposmotic medium, hyperosmolarity left V O2 of trout hepatocytes unaltered, despite the fact that the cells were still in a shrunken state at the time respiratory rate was assessed (Fig.·2). Similar observations have been reported for kidney cortex (Gyory et al, 1981) and L-929 cells (Clegg and Gordon, 1985), in which hyperosmotic conditions were also without effect on VO 2 . It has been hypothesised by Clegg and Gordon (1985) that this reflects the highly structured organisation of cellular metabolism, which may render endogenous respiration of the cells largely independent of metabolite concentration in the aqueous cell compartments.…”

Respiratory metabolism of L‐929 cells at different water contents and volumes

“…These and other similar earlier studies have been summarized in a book by Olmstead (1966). More recently Gyory et al (1981) showed that a 32% reduction in rat kidney cortex cell volume (probably amounting to a 50% water loss) had no effect on the rate of endogenous oxygen consumption, using the trisaccharide raffinose as the "nonpenetrating" solute to decrease water activity in the medium. Olson and Holtzman (1982) found that rat cerebral astocytes (in primary culture) and 3T3 fibroblasts exhibited no change in the rate of endogenous respiration when the osmolarity of the medium was tripled (equivalent at least to our 0.6 m sorbitol-supplemented DBS).…”

Isovolumetric regulation of isolated S2 proximal tubules in anisotonic media.

“…Previous studies ofrenal volume regulation have used tissue slices, cell suspensions, isolated tubules, and single cells (1)(2)(3)(4)(5)(6)(7)(8)(22)(23)(24)(25)(26)(27)(28)(29)(30). In all of these studies the medium osmolality was changed suddenly, which is uncharacteristic of osmotic changes that might be encountered in pathophysiologic states in vivo.…”