Abstract

Squid giant axons injected with arsenazo III as an intracellular Ca indicator will also be treated with TTX and TEA to pharmacologically block Na and K currents and will then be voltage clamped from a variety of resting potentials initially specified by changing the [K] in seawater. The family of curves for internal Ca vs. membrane potential will allow one to characterize the dependence of [Ca] in axoplasm on membrane potential. Other measurements will examine the dependence of Ca efflux on membrane potential. Finally, the factors influencing the inactivation of Na/Ca exchange in squid axons will be examined.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS017718-07
Application #
3397794
Study Section
Physiology Study Section (PHY)
Project Start
1981-07-01
Project End
1988-12-31
Budget Start
1987-07-01
Budget End
1988-12-31
Support Year
7
Fiscal Year
1987
Total Cost
Indirect Cost

  Institution

Name
University of Maryland Baltimore
Department
Type
Schools of Medicine
DUNS #
003255213
City
Baltimore
State
MD
Country
United States
Zip Code
21201

  Publications

Requena, J; Whittembury, J; Scarpa, A et al. (1991) Intracellular ionized calcium changes in squid giant axons monitored by Fura-2 and aequorin. Ann N Y Acad Sci 639:112-25
Requena, J; Whittembury, J; Mullins, L J (1989) Calcium entry in squid axons during voltage clamp pulses. Cell Calcium 10:413-23
Mullins, L J; Whittembury, J; Requena, J (1989) Changes in internal ionized Ca2+ and H+ in voltage clamped squid axons. Cell Calcium 10:401-12
Requena, J; Mullins, L J; Whittembury, J et al. (1986) Dependence of ionized and total Ca in squid axons on Nao-free or high-Ko conditions. J Gen Physiol 87:143-59
Vassort, G; Whittembury, J; Mullins, L J (1986) Increases in internal Ca2+ and decreases in internal H+ are induced by general anesthetics in squid axons. Biophys J 50:11-9
Mullins, L J; Requena, J; Whittembury, J (1985) Ca2+ entry in squid axons during voltage-clamp pulses is mainly Na+/Ca2+ exchange. Proc Natl Acad Sci U S A 82:1847-51
Requena, J; Whittembury, J; Tiffert, T et al. (1985) The influence of chemical agents on the level of ionized [Ca2+] in squid axons. J Gen Physiol 85:789-804