Advances in Clinical and Experimental Medicine
2015, vol. 24, nr 4, July-August, p. 579–584
Publication type: original article
Distribution in Rats Internal Organs of Intraperitoneally Given 125I-Labeled Heptapeptide [2-8]-Leucopyrokinin ([2-8]-LPK), a Truncated Analog of Insect Neuropeptide Leucopyrokinin
1 Medical Higher School in Sosnowiec, Poland
2 Pharmaceutical Research and Production Plant, “Biochefa”, Sosnowiec, Poland
3 Department of Histology and Embriology, Medical University of Silesia, Katowice, Poland
4 Department of Toxicology and Health Protection, Medical University of Silesia, Katowice, Poland
5 Faculty of Chemistry, University of Wroclaw, Poland
Background. It was previously found that synthetic, insect-derived octapeptide leucopyrokinin (LPK) applied directly into the lateral brain ventricle induced a significant antinociceptive effect in rats. Its synthetic truncated analog heptapeptide [2-8]-leucopyrokinin displayed a stronger antinociceptive effect in comparison to native LPK. Moreover it was previously found a high accumulation of these both 125I-labeled peptides in adrenals, as well as in hypothalamus and in hippocampus of rats brain.
Objectives. The aim of the present study was to assess the distribution of 125I-labeled [2-8]-leucopyrokinin in rats’ internal organs an in several parts of the brain after peripheral – intraperitoneal (i.p.) administration.
Material and Methods. The study was performed on male Wistar rats. A synthetic [2-8]-leucopyrokinin ([2-8]-LPK) was iodinated with Na125I. On the day of experiment a solution of 125I-[2-8]-LPK was i.p. injected and the next after 1 and 24 h animals were sacrificed by decapitation. Radioactivity levels in samples of parts of the brain and of internal organs were determined by counter Gamma Auto Count.
Results. A uniform, low accumulation 125I-[2-8]-LPK was found in evaluated samples of the brain and in internal organs.
Conclusion. The results of the present study indicate a weak penetration into the brain and internal organs of intraperitoneally applied 125I-[2-8]-LPK in rats and correspond with previously determined weak biological effects of i.p. injected LPK and [2-8]-LPK.
[2-8]-leucopyrokinin, distribution in rat brain and internal organs, intraperitoneal administration.
- Nachman RJ, Holman GM, Cook BJ: Active fragments and analogs of the insect neuropeptide leucopyrokinin: structure-function studies. Biophys Res Commun 1986, 137, 936–942.
- Holman GM, Cook BJ, Nachman RJ: Isolation, primary structure and synthesis of two neuropeptides from Lecophaea maderae: members of new family of cephalomyotropins. Comp Biochem Physiol 1986, 84 C, 205–211.
- Konopińska D, Rosiński G, Sobótka W: Insect peptide hormones, an overview of the present literature. Int J Peptide Protein Res 1992, 39, 1–11.
- Rykaczewska M, Konopińska D, Brus R, Plech A: Antinociceptive effect of leucopyrokinin in rats. Pol J Pharmacol Pharm 1992, 44, 215–216.
- Plech A, Rykaczewska-Czerwińska M, Bartosz-Bechowski H, Lombarska-Śliwińska D, Małota M, Szewczyk M, Brus R, Konopińska D: Insect neuropeptide leucopyrokinin analogues – synthesis and antinociceptive effect in rats. Pol J Pharmacol 1997, 49, 119–126.
- Rykaczewska-Czerwińska M, Konopińska D, Plech A: Behavioural effects of [2-8]-leucopyrokinin ([2-8]-LPK), an active, synthetic analogue of insect neuropeptide leucopyrokinin (LPK) in rats. Pestycydy/Pesticides 2004, 3–4, 123–132.
- Rykaczewska-Czerwińska M, Konopińska D, Plech A: The effect of the leucopyrokinin analogue: [2-8]-leucopyrokinin on central opioid receptors in rats. Comp Biochem Physiol 2001, 130C, 271–279.
- Rykaczewska-Czerwińska M, Lombarska-Śliwińska D, Konopińska D, Plech A: Effect of insect neuropeptide leucopyrokinin (LPK) on rectal temperature in rats. Preliminarystudy. Pestycydy/Pesticides 2004, 133–139.
- Rykaczewska-Czerwińska M, Lombarska-Śliwińska D, Konopińska D, Plech A: Central termoregulatory effect of insect neuropeptide leukopyrokinin (LPK) in rats. Pestycydy/Pesticides 2005, 125–131.
- Plech A, Rykaczewska-Czerwińska M, Ryszka F, Suszka-Świtek A, Dolińska B, Konopińska D: Distribution of 125I-labeled leucopyrokinin in rats. Intern J Tissue React 2003, 25, 65–71.
- Plech A, Rykaczewska-Czerwińska M, Ryszka F, Suszka-Świtek A, Dolińska B, Konopińska D: Distribution of 125I-labeled [2-8]-leucopyrokinin, active analog of leucopyrokinin in rats. Acta Pol Pharm – Drug Res 2005, 62, 393–397.
- Plech A, Rykaczewska-Czerwińska M, Ryszka F, Suszka-Świtek A, Dolińska B, Kuczer M, Konopińska D: Distribution in rat brain and internal organs of 125I-labeled leucopyrokinin (LPK) injected intraperitoneally. Pestycydy/Pesticides 2005, 153–160.
- Kokot F, Stupnicki R: Metody radioimmunologiczne i radiokompetycyjne stosowane w klinice. PZWL, Warszawa 1986, 123.
- Tallarida RJ, Murray RB: Manual of pharmacologic calculation with computer programs. Springer Verlag, New York 1985, 2nd ed., 100, 145.
- Ryszka F, Chylak M, Dolińska B, Suszka-Świtek A: Uptake of prolactin and thyroliberin by the heart. Intern J Tissue React 2000, 22, 101–104.
- Ryszka F, Dolińska B, Suszka-Świtek A: Distribution of prolactin in selected rat organs and tissues. Intern J Tissue React 2002, 24, 33–36.
- Banks WA, Kastin AJ: Peptides and blood-brain barrier: lipophilicity as a predictor of permeability. Brain Res Bull 1985, 15, 287–292.