Sugimori M, Cherksey B, Llinas R.
Abstr Soc Neurosci. 1991; 17: 1162.
Dept. of Physiology and Biophysics, NYU Medical Center 10016.
Dissociated cerebellar Purkinje cells from guinea pig were studied using whole cell voltage clamp technique (Kay 1989, Dissection of tissue culture, Alan R. Liss Inc.). The properties of synthetic arginine-polyamines derived as possible analogs of the naturally occuring FTX (Cherksey et al 1989, Biol. Bull., 177: 321) were tested as potential calcium channel blockers. Three structures were studied FTX(3:3), FTX(4:3) and FTX(3:4) (see Cherksey et al. this meeting). The results indicate that of these three polyamines FTX(3:3), FTX(4:3) and FTX(3:4) have decreasing abilities of blocking. The most potent FTX(3:3) is capable of reducing calcium currents at the initial dose at the 100 nanomolar level. This block increases in magnitude such that at close to ten micromolar level calcium current is almost totally blocked. A similar set of experiments in which FTX(4:3) and FTX(3:4) permutations of polyamine were tested demonstrate that the FTX(4:3) was approximately one order of magnitude less potent than FTX(3:3) and that the FTX(3:4) permutation was basically not effective. These results indicate that FTX action-like polyamines, which have a dose response curve suggesting a powerful binding to these channels, have been shown to be specific blockers for the so-called P-channel (Llinas et al 1989, PNAS 86:1689). Moreover these polyamines, which do not block the L, T or N type calcium channels (Fox et al 1987, J. Physiol. 394: 149) or the sodium or potassium currents at the levels utilized, may ultimately represent an element of a family of polyamines, normally present in the brain, that regulate channel activity.
Publication Types:
Keywords:
- Calcium
- Calcium Channel Agonists
- Calcium Channel Blockers
- Calcium Channels
- Patch-Clamp Techniques
- Polyamines
- Potassium
- Purkinje Cells
- arginine polyamine
Other ID:
UI: 102212513
From Meeting Abstracts