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Insights of the effects of polyethylene glycol 400 on mammalian and avian nerve terminals
Author(s) -
Oshima Mário,
Leite Gildo Bernardo,
RostelatoFerreira Sandro,
Da CruzHöfling Maria Alice,
RodriguesSimioni Léa,
OshimaFranco Yoko
Publication year - 2010
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.21531
Subject(s) - acetylcholine , peg ratio , chemistry , sarcolemma , polyethylene glycol , biophysics , dantrolene , neuromuscular transmission , neurotransmission , stimulation , neostigmine , biochemistry , pharmacology , calcium , endocrinology , membrane , biology , receptor , organic chemistry , finance , economics
Polyethylene glycol (PEG) has been widely used as a solvent among other applications. An ideal solvent is one that does not interfere with an in vitro biological system, unless it is a bioactive agent. Herein, a facilitatory neurotransmission effect was exhibited by PEG (20 μM) in mammalian (67 ± 12.5%, n = 4) and avian (74 ± 6.8%, n = 6) neuromuscular preparations. In curarized preparations, PEG did not reverse the neurotransmission blockade induced by D‐tubocurarine (D‐Tc, 5.8 μM, n = 6) as promoted by neostigmine (12 μM, n = 4). A possible presynaptic action of PEG was ruled out, because quantal acetylcholine (ACh) content was similar to the control Tyrode‐incubated mammalian preparation. PEG showed improved sarcolemmal sensitivity, both under direct (sarcolemma) and indirect stimulation (motor axon), because it was able to release calcium from the sarcoplasmic reticulum, even when 30 μM dantrolene ( n = 5) was previously applied. Neurotransmission decreased at a higher PEG concentration (100 μM, n = −6) in the depolarized membrane, but it did not alter normal muscle fiber morphology. In addition, it partially recovered twitch tension amplitude (55 ± 5.7%) after washing the preparations. More than a simple solvent, we suggest that PEG 400 is able to act on the sarcolemmal membrane, probably at the triad level, which is in line with its well‐known ability as drug carrier. Muscle Nerve, 2010