The action of polymyxin B at the frog neuromuscular junction

British Journal of Pharmacology
N N Durant, J J Lambert

Abstract

1 The effects of polymyxin B at the neuromuscular junction of the frog were studied by conventional electrophysiological and voltage clamp techniques. 2 At a concentration of 2.5 micrograms/ml polymyxin B produced neuromuscular blockade in 10 to 15 min neuromuscular block was characterized by a depressed e.p.p. quantal content (28 plus or minus 7), which was similar to that determined from endplates exposed to 13 mM magnesium (23 plus or minus 3), and a low e.p.p. quantal size, which was similar to that determined from endplates exposed to 3 microM (+)-tubocurarine. 3 Polymyxin B (0.25 to 0.75 micrograms/ml) decreased mean miniature e.p.pl amplitude with little effect on frequency. At a concentration of 5 micrograms/ml polymyxin B markedly shortened the duration of endplate currents (e.p.cs) and abolished the relationship between holding potential and the time to half-decay at negative potentials greater than -60 mV. This action is consistent with block of open acetylcholine activated ionic channels. 5 4-Aminopyridine (20 micrometers) antagonized the depressed e.p.p. quantal content produced by polymyxin B but did not alter the shortened e.p.c. duration. 6 It is concluded that polymyxin B decreases quantal release and produces ...Continue Reading

References

Dec 4, 1978·Proceedings of the Royal Society of London. Series B, Containing Papers of a Biological Character·B Katz, R Miledi
Apr 1, 1975·Archives of Neurology·M P McQuillen, L Engbaek
Dec 1, 1976·Canadian Journal of Physiology and Pharmacology·J M Wright, B Collier
May 1, 1977·Anesthesia and Analgesia·C LeeE L Nagel
Aug 15, 1977·European Journal of Pharmacology·A L Harvey, I G Marshall
Sep 1, 1978·Journal of Pharmaceutical Sciences·D V Viswanath, H J Jenkins
Oct 25, 1979·Nature·J F FiekersR L Parsons
Jun 1, 1977·The Journal of Physiology·P R Adams
May 1, 1970·Anesthesia and Analgesia·C B PittingerR Adamson
Jan 1, 1972·Annual Review of Pharmacology·C Pittinger, R Adamson
May 1, 1972·The Journal of Physiology·K L Magleby, C F Stevens
Jun 1, 1965·The Journal of Physiology·D Elmqvist, D M Quastel
May 28, 1954·The Journal of Physiology·J DEL CASTILLO, L ENGBAEK
Jun 28, 1954·The Journal of Physiology·J DEL CASTILLO, B KATZ
Oct 28, 1955·The Journal of Physiology·A R MARTIN
Feb 1, 1962·Acta Physiologica Scandinavica·D ELMQVIST, J O JOSEFSSON

❮ Previous
Next ❯

Citations

Apr 1, 1992·Cellular and Molecular Neurobiology·K SzczawinskaV A Eterović
Nov 13, 1984·European Journal of Pharmacology·P T BiesselsA S Horn
Jan 2, 1989·European Journal of Pharmacology·O V BrazilN J Pavani
Oct 15, 1991·European Journal of Pharmacology·P E Light, S J Publicover
Sep 15, 2020·Frontiers in Molecular Neuroscience·Martin KrennFritz Zimprich

❮ Previous
Next ❯

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.

Related Papers

Comparative Biochemistry and Physiology. C, Comparative Pharmacology and Toxicology
A B Ribera, W L Nastuk
Journal of Neurology, Neurosurgery, and Psychiatry
R Sandyk, M J Brennan
© 2021 Meta ULC. All rights reserved