Acıbadem Üniversitesi Sağlık Bilimleri Dergisi 2011 , Vol 2, Issue 2
Effects of Electrical Stimulation and K+ Depolarization On The Release and Contents of Acetlcholine and Choline In Superfused Slices From Rat Striatum
İsmail Hakkı Ulus
Acıbadem Üniversitesi Tıp Fakültesi, Farmakoloji, İstanbul, Türkiye Effects of electrical stimulation and potassium depolarization on acetylcholine and choline release and synthesis in rat brain striatal slices

Objective: The aim of the study was to determine effects of electrical stimulation and potassium depolarization on acetylcholine and choline release and synthesis in rat brain striatal slices

Methods: Striatal slices from rat brain were perfused with physiological medium under basal and stimulated conditions, either with electrically or high potassium medium, for 120 min. Acetylcholine and choline contents of the perfusate and tissue were assayed radioenzymatically.

Results: Striatal slices released 376±20 pmol/mg protein/120 min acetylcholine and 2375±85 pmol/mg protein/120 min choline into the perfusate at rest. When sliced stimulated by high potassium or electrically, acetylcholine release into the perfusate were increased by 5-6 folds and reached to 2360±85 or 2830±174 pmol/mg protein/120 min, respectively. Choline release into perfusate was not change during electrical stimulation. During high potassium depolarization, choline release increased by 50% at first 20-min period but decreased by 25% during the whole of 120-min period. The tissue contents of acetylcholine, but not choline, decreased slightly (by 20%; p<0.05) during electrical stimulation. While during high potassium depolarization the tissue acetylcholine and choline contents were both decreased (p<0.001), by greater extend, by about 80% and 50%, respectively. Acetylcholine and choline synthesis were 391±21 and 2435±170 pmol/mg protein, 2345±165 and 2203±95 pmol/mg protein or 960±65 and 1241±105 pmol/mg protein at rest, during electrical stimulation or high potassium depolarization, respectively.

Conclusion: These data show that electrical stimulation and potassium depolarization have different effect on acetylcholine and choline synthesis and release in striatal slices. Electrical stimulation enhances synthesis and release of acetylcholine and choline, while stimulation with high potassium results with increase in acetylcholine synthesis and release and decline in choline release and production. Keywords : striatal slices, acetlcholine, choline, eletrical stimulation, K+ depolarization