title: Effects of divalent cations on bovine corneal stromal swelling rates.
abstract: OBJECTIVE
  The corneal stroma swells with edema fluid due to electrostatic repulsion of its negatively charged glycosaminoglycans, and divalent metal cations inhibit edema development. We investigated whether or not nonmetal divalent cations might also inhibit edema development.
  
  
  METHODS
  We investigated the hydration rates of stromas bathed in phosphate-buffered saline (PBS) or phosphate-buffered magnesium sulfate, calcium chloride, hexamethonium dihydrochloride, putrescine dihydrochloride, and ethylenediamine hydrochloride solutions at pH 7.35-7.4.
  
  
  RESULTS
  Hydration rate was fastest in PBS and slower in divalent cation salt solutions (p < 0.05). All metal and nonmetal divalent cations inhibited swelling rates compared to PBS. Ethylenediamine is not divalent at physiological pH and did not significantly inhibit swelling.
  
  
  CONCLUSIONS
  All the divalent cations appear to decrease swelling relatively equally, probably by shielding negative charges on GAGs, reducing their electrostatic repulsions.
authors.affiliation: Biophysics and Physiology Laboratory, Department of Biology, University of West Georgia, Carrollton, Georgia 30118, USA.
authors.forename: Zachary Scott
authors.initials: ZS
authors.lastname: Hogan
authors.forename: Kimberly Leigh
authors.initials: KL
authors.lastname: Brown
authors.forename: Adenike
authors.initials: A
authors.lastname: Ishola
authors.forename: Jane
authors.initials: J
authors.lastname: Gatimu
authors.forename: LaQuetta
authors.initials: L
authors.lastname: Flucker
authors.forename: Joseph William
authors.initials: JW
authors.lastname: Huff
mesh_terms: D000818:Animals; D002122:Calcium Chloride / Q000494:pharmacology; D002413:Cations, Divalent / Q000494:pharmacology*; D002417:Cattle; D015715:Corneal Edema / Q000139:chemically induced* / Q000175:diagnosis; D003319:Corneal Stroma / Q000187:drug effects* / Q000473:pathology; D005029:Ethylenediamines / Q000494:pharmacology; D018738:Hexamethonium / Q000494:pharmacology; D008278:Magnesium Sulfate / Q000494:pharmacology; D011700:Putrescine / Q000494:pharmacology
chemical_list: D002413:Cations, Divalent; D005029:Ethylenediamines; D018738:Hexamethonium; C031234:ethylenediamine; D008278:Magnesium Sulfate; D002122:Calcium Chloride; D011700:Putrescine