Ionic Mechanisme Action Of Severals Amino Acids on Leech Ganglia

Author

Abdul Manan Mat Jais

Proceeding

The Fifteenth Malaysian Biochemical Society In Conference : Focus on Biochemistry in Malaysia in the 1990's, Faculty Of Medicine Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia.

Date

3/9/1990

Keyword

leech, Hirudo medicinalis, ionic mechanisms, amino acids

Abstract

Intracellular recordings were made from Retzius cells of the leech, Hirudo medicinalis, and ionic mechanisms of L-glutamate, ibotenate, quisqualate and kainate were examined. In Na+ free Ringer, all the amino acids responses were abolished or greatly reduced. However, the increase in Ca** (10 mM) resulted in the recovery of the kainate, and some of the quisqualate reaction. Cobalt had blocked the kainate response in Na* free high Ca+* Ringer. All the amino acids responses were associated with an increase in conductance: L-glutamate and ibotenate are dependent on sodium; quisqualate is mainly sodium dependent with a small calcium component; but the calcium can completely substitute for the sodium vrNa+free high Ca** Ringer. These studies provide evidence that L-glutamate and ibotenate act on a common receptor, while quisqualate and kainate on different receptors.