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Acutely Administered Leptin Increases [Ca2+]i and BKCa Currents But Does Not Alter Chemosensory Behavior in Rat Carotid Body Type I Cells

  • Richard L. Pye
  • Eric J. Dunn
  • Ellen M. Ricker
  • Jennifer G. Jurcsisn
  • Barbara L. Barr
  • Christopher N. WyattEmail author
Chapter
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 860)

Abstract

Obesity related pathologies are the health care crisis of our generation. The fat cell derived adipokine leptin has been shown to be a central stimulant of respiration. Very high levels of leptin, however, are associated with the depressed ventilatory phenotype observed in obesity hypoventilation syndrome. Leptin receptors have been identified on carotid body type I cells but how their activation might influence the physiology of these cells is not known.

The acute application of leptin evoked calcium signaling responses in isolated type I cells. Cells increased their Fura 2 ratio by 0.074 ± 0.010 ratio units (n = 39, P < 0.001). Leptin also increased the peak membrane currents in 6 of 9 cells increasing the peak macroscopic currents at +10 mV by 61 ± 14 % (p < 0.02). Leptin administered in the presence of the selective BKCa channel inhibitor Paxilline (0.5 μM) failed to increase membrane currents (n = 5). Interestingly, leptin did not significantly alter the resting membrane potential of isolated type I cells (n = 9) and anoxic/acidic depolarizations were unaffected by leptin (n = 7, n = 6).

These data suggest that leptin receptors are functional in type I cells but that their acute activation does not alter chemosensory properties. Future studies will use chronic models of leptin dysregulation.

Keywords

Carotid body Type I cells Leptin Ca2+ imaging Voltage-clamp Current-clamp 

Notes

Acknowledgements

This work was supported by NIH-1RO1HL091836

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Copyright information

© Springer International Publishing Switzerland 2015

Authors and Affiliations

  • Richard L. Pye
    • 1
  • Eric J. Dunn
    • 1
  • Ellen M. Ricker
    • 1
  • Jennifer G. Jurcsisn
    • 1
  • Barbara L. Barr
    • 1
  • Christopher N. Wyatt
    • 1
    Email author
  1. 1.Department of Neuroscience, Cell Biology and PhysiologyWright State UniversityDaytonUSA

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