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Penicillin‐induced potentiation of glycine receptor‐operated choride current in rat ventro‐medial hypothalamic neurones
Author(s) -
Tokutomi Naofumi,
Agopyan Nadia,
Akaike Norio
Publication year - 1992
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1992.tb14295.x
Subject(s) - long term potentiation , glycine , chemistry , patch clamp , endocrinology , electrophysiology , medicine , biophysics , receptor , biochemistry , biology , amino acid
1 Effects of penicillin G (PCN) on glycine (Gly)‐evoked Cl − current ( I Gly ) were investigated in acutely dissociated rat ventro‐medial hypothalamic (VMH) neurones by the whole cell mode of patch clamp technique. 2 When PCN was applied simultaneously with Gly, PCN depressed I Gly like a Cl − channel blocker. 3 The PCN‐induced blocking action was clearly observed at a low PCN concentration (30 u), while the maximal blockade was achieved by 600 u (units per 10 ml) PCN. 4 When tested solution containing both PCN and Gly was quickly substituted with one containing Gly only, a new rebound‐like transient current ( I T ) which also passed through Cl − channel, was elicited. 5 The peak amplitude of I T induced by PCN at concentrations higher than 100 u was greater than that induced by glycine alone. We termed this phenomenon PCN‐induced potentiation of I Gly . In all cells tested, PCN potentiated I Gly . 6 At a lower PCN concentration below 30 u, I T generation was not clear in the presence of 10 −5 m γ‐aminobutyric acid. With PCN a higher concentration than 300 u, I T amplitude was treater than that of the original peak I Gly . This was observed in 18 neurones out of 21. The maximal amplitude of the I T was achieved with 600 u PCN.