Danuta Konopińska

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1. The neuropeptide proctolin (Arg-Tyr-Leu-Pro-Thr) both potentiates neurally evoked contractions and causes contractures of insect skeletal muscle. In the hindleg extensor tibiae muscle of the locust, Schistocerca gregaria, the proctolin analogue [Afb (p-NO2)2]-proctolin is also able to potentiate neurally evoked contractions but is approximately(More)
Continuing our studies on proctolin (Arg-Tyr-Leu-Pro-Thr) we performed the synthesis and biological evaluation of 52 analogues substituted in position 2, 3, 4, and 5 of the peptide chain. The peptides were bioassayed for cardiotropic activity in vitro on Tenebrio molitor and myotropic activity on foregut of Schistocerca gregaria. Twenty analogues retained(More)
The effect of the ant venom neuropeptide--poneratoxin (PoTX)--on neuromuscular transmission in rat diaphragm tissue was studied by means of intracellular recordings of spontaneous miniature endplate potentials (MEPPs) and of nerve evoked endplate potentials (EPPs). A 2 microM concentration of PoTX caused a pronounced but transient increase in MEPPs(More)
The antinociceptive effect of intracerebroventricular injections of [2-8]-leucopyrokinin (LPK), a truncated leucopyrokinin analogue, was determined in rats, by means of a tail immersion test. We found a significant antinociceptive effect of three i.c.v. doses of [2-8]-LPK: 1, 5 and 10 nmol. Pre-treating animals with naloxone hydrochloride (1 mg/kg i.p.)(More)
The brain and internal organs distribution of 125I-labeled [2-8]-leucopyrokinin ([2-8]-LPK), a truncated analog of leucopyrokinin (LPK), an insect myotropic peptide injected into the lateral brain ventricle was determined in rats. A high accumulation of this analog in adrenals and in the hypothalamus and hippocampus of the brain was found. A lesser but(More)
It has been previously found in our laboratory that insect neuropeptide leucopyrokinin and [2-8]-leucopyrokinin, a truncated analog without the first aminoacid of leucopyrokinin peptide chain exert an antinociceptive effect in rats. The present study confirmed our previous results, and moreover it has been found that [d-Ala(5)]-[2-8]-leucopyrokinin, an(More)
The distribution in parts of the brain and internal organs of 125J-labeled leucopyrokinin (LPK), an insect myotropic peptide injected into the lateral brain ventricle was determined in rats. A high accumulation of this peptide in adrenals and in the hypothalamus and hippocampus of the brain was found. A lesser but significant LPK accumulation in other(More)
To explain the role of the Thr5 residue of proctolin (Arg-Tyr-Leu-Pro-Thr) in the myotropic activity of this insect neuropeptide, we synthesized two groups of its analogues: 1) Arg-Tyr-Leu-Pro-X-OH with X = Val (1), D-Val (2), Ile (3), D-Ile (4), Ala (5), D-Ala (6), Asn (7), Gln (8), Ser (9), Pro (10), Phe (11), Asp (12), Glu (13), Arg (14), D-Arg (15), Lys(More)
The central action of periplanetin CC-1 (Pea-HrTH) (Glp-Val-Asn-Phe-Ser-Pro-Asn-TrpNH2), octapeptide of the insect adipokinetic hormone family (AKH-family), isolated from American cockroach-Periplaneta americana, was studied in Albino Swiss mice (20-25 g). CC-1 was injected intracerebroventricularly (i.c.v.) in the volume of 5 microliters at the dose of 50(More)
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