Acetylcholine effect on plasma membrane transport systems of characean cells

• Main Author: Kisnierienė, Vilma
• Other Authors: Rukšėnas, Osvaldas
• Format: Doctoral or Postdoctoral Thesis
• Language: Lithuanian; English
• Published: Institutional Repository of Vilnius University 2014
• Subjects: plant action potentials; plant electrophysiology; plant cholinergic system; Characeae; Nitella flexilis
• Online Access: https://repository.vu.lt/VU:ELABAETD1927918&prefLang=en_US

The main goal of the present study was to investigate the effect of acetylcholine (ACh) on the activity of ion transport systems and action potential (AP) generation dynamics in Nitella flexilis and Nitellopsis obtusa plasma membrane. The measurements were carried out using a conventional microelectrode technique and voltage clamp method. The membrane potential dynamics after repetitively triggered action potentials were explored for evaluation of chemical treatment impact on functionality of plasma membrane transport processes. Action of acetylcholine on membrane bioelectrogenesis as well as the effect of acetilcholinesterase inhibitors on ACh induced membrane potential changes in Characeaen cells was examined. The influence of ACh agonist nicotine on electrical responses of Nitellopsis obtusa cells was investigated and membrane potential depolarization after ACh and nicotine application has been shown. Changes in AP after application of ACh indicate effect of ACh on ion channels involved in AP generation. The main finding is that 5 mM ACh activates K+ ion channels at the rest, Cl- and Ca2+ ion channels after excitation and enhances activation of H+ATPase. The increase in excitability of Nitellopsis obtusa cells after ACh has been demonstrated. AChE activity in Characeaen cells has been supposed based on the electrophysiological data. We propose that membrane potential dynamics triggered by repetitive stimulation could be used in ecotoxicology.