Submit a comment

Glucose-Stimulated 45Calcium Efflux from Isolated Rat Pancreatic Islets
Barbara J. Frankel, … , Rudolph E. Fanska, Gerold M. Grodsky
Barbara J. Frankel, … , Rudolph E. Fanska, Gerold M. Grodsky
Published September 1, 1978
Citation Information: J Clin Invest. 1978;62(3):525-531. https://doi.org/10.1172/JCI109156.
View: Text | PDF
Research Article

Glucose-Stimulated 45Calcium Efflux from Isolated Rat Pancreatic Islets

Abstract

Kinetics of 45Ca efflux and insulin release were studied in collagenase-isolated rat islets during 2-h perifusions with calcium-depleted (0.05 mM) bicarbonate-phosphate buffer containing 2.2 mM glucose. Addition of glucose (16.7 mM) suppressed 45Ca efflux by 30%. Removal of glucose caused an “off response” of insulin release. The perifusion of a normal concentration of Ca (2.3 mM) greatly stimulated 45Ca efflux, indicating Ca ↔ 45Ca exchange. When Ca and glucose were superimposed, the effects on 45Ca efflux and insulin release depended upon the order of presentation of the stimuli: when Ca was added to an ongoing 16.7-mM glucose perifusion, biphasic patterns of 45Ca and insulin release were seen; when glucose was superimposed on a Ca perifusion, an inhibition of the Ca-stimulated 45Ca efflux occurred, and a reduced but clearly biphasic insulin response was seen. The subsequent insulin off response after with-drawal of the glucose was also reduced.

Authors

Barbara J. Frankel, Walter T. Imagawa, Michael D. L. O'Connor, Ingmar Lundquist, John A. Kromhout, Rudolph E. Fanska, Gerold M. Grodsky

×

Guidelines

The Editorial Board will only consider comments that are deemed relevant and of interest to readers. The Journal will not post data that have not been subjected to peer review; or a comment that is essentially a reiteration of another comment.

  • Comments appear on the Journal’s website and are linked from the original article’s web page.
  • Authors are notified by email if their comments are posted.
  • The Journal reserves the right to edit comments for length and clarity.
  • No appeals will be considered.
  • Comments are not indexed in PubMed.

Specific requirements

  • Maximum length, 400 words
  • Entered as plain text or HTML
  • Author’s name and email address, to be posted with the comment
  • Declaration of all potential conflicts of interest (even if these are not ultimately posted); see the Journal’s conflict-of-interest policy
  • Comments may not include figures
This field is required
This field is required
This field is required
This field is required
This field is required
This field is required