Influence of Integrin-blocking Peptide on Gadolinium- and Hypertonic Shrinking-induced Neurotransmitter Release in Rat Brain Synaptosomes

• Published in: Neurochemical research Vol. 33; no. 7; pp. 1316 - 1324
• Main Authors: Waseem, Tatyana V., Lapatsina, Liudmila P., Fedorovich, Sergei V.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.07.2008; Springer Nature B.V
• Subjects: Animals; Aspartic Acid - metabolism; Biochemistry; Biomedical and Life Sciences; Biomedicine; Brain Chemistry - drug effects; Cations - pharmacology; Cell Biology; Dose-Response Relationship, Drug; Exocytosis - drug effects; Fluorescent Dyes; Gadolinium - pharmacology; gamma-Aminobutyric Acid - metabolism; Hypertonic Solutions - pharmacology; Integrins - antagonists & inhibitors; Nerve Tissue Proteins - metabolism; Neurochemistry; Neurology; Neurosciences; Neurotransmitter Agents - metabolism; Oligopeptides - pharmacology; Original Paper; Pyridinium Compounds; Quaternary Ammonium Compounds; Rats; Rats, Wistar; Sucrose - pharmacology; Synaptosomes - drug effects; Synaptosomes - metabolism; Gadolinium; Hypertonic; Neurotransmitter release; Integrin; Synaptosomes; Exocytosis
• ISSN: 0364-3190; 1573-6903
• DOI: 10.1007/s11064-007-9585-5

Polyvalent cations and hypertonic shrinking of presynaptic endings lead to calcium-independent exocytosis in various synapses. In the present study we have investigated the contribution of integrins to this phenomenon. It was found that hypertonic shrinking, polyvalent cations ruthenium red and gadolinium results in dose-dependent calcium-independent neurotransmitter release in rat brain synaptosomes. The exocytotic mechanism of neurotransmitter release induced by 300 μM gadolinium was additionally verified by the fluorescent dye FM2-10. We found that 200 μM of RGDS peptide, an inhibitor of integrins, decreased polyvalent gadolinium-induced [ 3 H] d -aspartate release by 26%. This compound had no effect upon hypertonicity-induced release. The peptide RGES, a negative control for RGDS; genistein, an inhibitor of tyrosine kinases; and citrate, an inhibitor of lanthanides-induced aggregation were ineffective in both cases. Therefore, we have shown that integrins did not influence hypertonicity-evoked [ 3 H] d -aspartate release, but partially mediated that evoked by gadolinium ions.