Detection of multiple patterns of oscillatory oxygen consumption in single mouse islets of Langerhans

Biochem Biophys Res Commun. 1999 Jun 7;259(2):331-5. doi: 10.1006/bbrc.1999.0784.

Abstract

A novel oxygen microsensor was used to measure oxygen levels in single mouse islets as a function of glucose concentration. Oxygen consumption of individual islets was 5.99 +/- 1.17, 9.21 +/- 2.15, and 12.22 +/- 2.16 pmol/min at 3, 10, and 20 mM glucose, respectively (mean +/- SEM, n = 10). Consumption of oxygen was islet-size dependent as larger islets consumed more oxygen than smaller islets but smaller islets consumed more oxygen per unit volume than larger islets. Elevating glucose levels from 3 to 10 mM induced pronounced fast oscillations in oxygen level (period of 12.1 +/- 1.7 s, n = 6) superimposed on top of large slow oscillations (period of 3.3 +/- 0.6 min, n = 6). The fast oscillations could be completely abolished by treatment with the L-type Ca2+-channel blocker nifedipine (40 microM) with a lesser effect on slow oscillations. Slow oscillations were almost completely dependent upon extracellular Ca2+. The oxygen patterns closely mimic those that have previously been reported for intracellular Ca2+ levels and are suggestive of an important role for Ca2+ in amplifying metabolic oscillations.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Biosensing Techniques
  • Calcium / pharmacology
  • Calcium Channel Blockers / pharmacology
  • Cell Respiration / drug effects
  • Glucose / metabolism
  • Islets of Langerhans / metabolism*
  • Mice
  • Nifedipine / pharmacology
  • Oxygen / analysis
  • Oxygen Consumption*

Substances

  • Calcium Channel Blockers
  • Nifedipine
  • Glucose
  • Oxygen
  • Calcium