Pharmacological properties of kryptopyrrole and its oxidation products on isolated sciatic nerve of rat and on guinea-pig ileum.

Abstract

1 Kryptopyrrole (2, 4-dimethyl, 3-ethylpyrrole) inhibited conduction in rat sciatic nerve by a local anaesthetic action. 2 Tone and both spontaneous and electrically-induced contractions of guinea-pig ileum were also inhibited by kryptopyrrole. The concentration of kryptopyrrole required for 50% inhibition of a maximum twitch tension (ID50) was 0.085 mM. 3 Oxidation products of kryptopyrrole with chromatographic properties similar to those of urinary constituents reported in schizophrenia and hepatic porphyrias had little or no effect at similar concentrations. 4 Dose-response curves to exogenous acetylcholine in guinea-pig ileum were shifted to the right by kryptopyrrole, with loss of parallelism and reduction in the maximum contraction. 5 Acetylcholine overflow from ileal segments at rest and during electrical stimulation was reduced by kryptopyrrole. 6 These results on ileal segments are consistent with kryptopyrrole having both a post-junctional site of action, presumably directly on the muscle, and a pre-junctional site reducing the output of acetylcholine from the myenteric plexus. 7 The significance of these findings is discussed in relation to a possible clinical pathological role for these compounds.

• Authors: A Gorchein, L D Mitchell, A T Rogers
• Journal: British journal of pharmacology (Br J Pharmacol) Vol. 65 Issue 1 Pg. 23-7 (Jan 1979) ISSN: 0007-1188 [Print] England
• PMID: 760888 (Publication Type: Journal Article)

Chemical References

• Pyrroles
• kryptopyrrole
• Acetylcholine

Topics

• Acetylcholine (metabolism)
• Action Potentials (drug effects)
• Animals
• Guinea Pigs
• Ileum (drug effects, metabolism)
• In Vitro Techniques
• Male
• Muscle Contraction (drug effects)
• Muscle, Smooth (drug effects, metabolism)
• Oxidation-Reduction
• Pyrroles (pharmacology)
• Rats
• Sciatic Nerve (drug effects)