title: Improved islet yield and function by use of a chloride channel blocker during collagenase digestion.
abstract: BACKGROUND
  Protection of pancreatic islets during isolation procedures is mandatory for successful islet transplantation. Chloride channel inhibition has been reported to prevent cell death induced by various stimuli. We examined the effects of the chloride channel blocker, 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid disodium salt (DIDS) and extracellular Cl(-)-free conditions on islet isolation outcomes.
  
  
  METHODS
  Experimental groups were created based on the collagenase solutions used for Wistar rat islet isolation: control group, Hanks' balanced salt solution; DIDS group, 200 μM DIDS; and Cl(-)-free group, sodium gluconate substituted for sodium chloride. We determined whether collagenase digestion induced the death of islet cells through Cl(-) influx into the cells. We then assessed islet yield and the viability of isolated islets.
  
  
  RESULTS
  We observed an increase in intracellular Cl(-) concentration under collagenase digestion conditions using a Cl(-)-sensitive fluorescent dye and subsequent rupture of islet cells. Consequently, islet yields were significantly higher in the DIDS and Cl(-)-free groups than in the control group, and islet morphology of the former groups was preserved. Of streptozotocin-induced diabetic severe combined immunodeficiency mice transplanted with a marginal dose of islets, all seven mice in the DIDS group and six of the seven mice in the Cl(-)-free group became normoglycemic, compared with two of seven mice in the control group (control vs. DIDS, P=0.010; control vs. Cl(-) free, P=0.051).
  
  
  CONCLUSIONS
  Our results indicate that DIDS inhibition of Cl(-) influx into islets protects islets during digestion procedures, offering a new strategy for the improvement of islet isolation outcomes.
authors.affiliation: Department of Organ Regenerative Surgery, Fukushima Medical University, Fukushima, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Anazawa
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Sato
authors.forename: Takuro
authors.initials: T
authors.lastname: Saito
authors.forename: Takao
authors.initials: T
authors.lastname: Tsuchiya
authors.forename: Akira
authors.initials: A
authors.lastname: Kenjo
authors.forename: Takashi
authors.initials: T
authors.lastname: Kimura
authors.forename: Junichiro
authors.initials: J
authors.lastname: Haga
authors.forename: Masao
authors.initials: M
authors.lastname: Miyake
authors.forename: Satoshi
authors.initials: S
authors.lastname: Waguri
authors.forename: Akihiro
authors.initials: A
authors.lastname: Hazama
authors.forename: Mitsukazu
authors.initials: M
authors.lastname: Gotoh
mesh_terms: D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid / Q000494:pharmacology*; D000818:Animals; D018118:Chloride Channels / Q000037:antagonists & inhibitors*; D017364:Collagenases / Q000494:pharmacology*; D005947:Glucose / Q000494:pharmacology; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D016381:Islets of Langerhans Transplantation; D008856:Microscopy, Fluorescence; D009926:Organ Preservation / Q000379:methods*; D051381:Rats; D017208:Rats, Wistar; D020858:Tissue and Organ Harvesting / Q000379:methods*
chemical_list: D018118:Chloride Channels; D007328:Insulin; D017364:Collagenases; D005947:Glucose; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid