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Leal AP, Oliveira RS, Perin APA, Borges BT, de Brum Vieira P, Dos Santos TG, Vinadé L, Valsecchi C, Belo CAD. Entomotoxic activity of Rhinella icterica (Spix, 1824) toad skin secretion in Nauphoeta cinerea cockroaches: An octopamine-like modulation. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2018; 148:175-181. [PMID: 29891370 DOI: 10.1016/j.pestbp.2018.04.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 04/21/2018] [Accepted: 04/25/2018] [Indexed: 06/08/2023]
Abstract
Rhinella icterica is a poisonous toad whose toxic secretion has never been studied against entomotoxic potential. Sublethal doses of Rhinella icterica toxic secretion (RITS) were assayed in Nauphoeta cinerea cockroaches, in order to understand the physiological and behavioral parameters, over the insect central and peripheral nervous system. RITS (10 μg/g) injections, induced behavioral impairment as evidenced by a significant decrease (38 ± 14%) in the distance traveled (p < .05), followed by an increase (90 ± 6%) of immobile episodes (p < .001, n = 28, respectively). In cockroaches semi-isolated heart preparations, RITS (16 μg/200 μl) induced a significant irreversible dose-dependent negative chronotropism, reaching ~40% decrease in heart rate in 20 min incubation. In in vivo cockroach neuromuscular preparations, RITS (20, 50 and 100 μg/g of animal weight) induced a time-dependent inhibition of twitch tension that was complete for 20 μg/g, in 120 min recordings. RITS (10 μg/g) also induced a significant increase in the insect leg grooming activity (128 ± 10%, n = 29, p < .01), but not in the antennae counterparts. The RITS increase in leg grooming activity was prevented in 90% by the pretreatment of cockroaches with phentolamine (0.1 μg/g). The electrophysiological recordings of spontaneous neural compound action potentials showed that RITS (20 μg/g) induced a significant increase in the number of events, as well as in the rise time and duration of the potentials. In conclusion, RITS showed to be entomotoxic, being the neuromuscular failure and cardiotoxic activity considered the main deleterious effects. The disturbance of the cockroaches' behavior together with the electrophysiological alterations, may unveil the presence of some toxic components present in the poison with inherent biotechnological potentials.
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Affiliation(s)
- Allan Pinto Leal
- Laboratório de Neurobiologia e Toxinologia, LANETOX, Universidade Federal do Pampa (UNIPAMPA), Av. Antônio Trilha 1847, 97300-000 São Gabriel, RS, Brazil
| | - Raquel Soares Oliveira
- Laboratório de Neurobiologia e Toxinologia, LANETOX, Universidade Federal do Pampa (UNIPAMPA), Av. Antônio Trilha 1847, 97300-000 São Gabriel, RS, Brazil
| | - Ana Paula Artusi Perin
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, prédio 43431, CEP 91501-970 Porto Alegre, RS, Brazil
| | - Bruna Trindade Borges
- Laboratório de Neurobiologia e Toxinologia, LANETOX, Universidade Federal do Pampa (UNIPAMPA), Av. Antônio Trilha 1847, 97300-000 São Gabriel, RS, Brazil
| | - Patrícia de Brum Vieira
- Laboratório de Neurobiologia e Toxinologia, LANETOX, Universidade Federal do Pampa (UNIPAMPA), Av. Antônio Trilha 1847, 97300-000 São Gabriel, RS, Brazil
| | - Tiago Gomes Dos Santos
- Laboratório de Estudos em Biodiversidade Pampiana LEBIP, Universidade Federal do Pampa (UNIPAMPA- SEDE), Av. Antônio Trilha 1847, 97300-000 São Gabriel, RS, Brazil
| | - Lúcia Vinadé
- Laboratório de Neurobiologia e Toxinologia, LANETOX, Universidade Federal do Pampa (UNIPAMPA), Av. Antônio Trilha 1847, 97300-000 São Gabriel, RS, Brazil
| | - Chiara Valsecchi
- Laboratório de Neurobiologia e Toxinologia, LANETOX, Universidade Federal do Pampa (UNIPAMPA), Av. Antônio Trilha 1847, 97300-000 São Gabriel, RS, Brazil
| | - Cháriston André Dal Belo
- Laboratório de Neurobiologia e Toxinologia, LANETOX, Universidade Federal do Pampa (UNIPAMPA), Av. Antônio Trilha 1847, 97300-000 São Gabriel, RS, Brazil; Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, prédio 43431, CEP 91501-970 Porto Alegre, RS, Brazil; Programa de Pós-Graduação em Ciências Biológicas: Bioquímica Toxicológica, (PPGBTox), Universidade Federal de Santa Maria (UFSM), Av. Roraima 1000, 97105-900 Santa Maria, RS, Brazil.
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Spittaels K, Vankeerberghen A, Schoofs L, Torrekens S, Grauwels L, Van Leuven F, De Loof A. Identification, characterization, and immunological localization of a novel myotropic neuropeptide in the Colorado potato beetle, Leptinotarsa decemlineata. Peptides 1995; 16:365-74. [PMID: 7651886 DOI: 10.1016/0196-9781(94)00205-k] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A novel myotropic heptapeptide was isolated from an extract of 54,000 heads of adult Leptinotarsa decemlineata by means of high performance liquid chromatography (HPLC), using the Locusta migratoria oviduct motility bioassay as monitoring system. The full primary structure was established as H-Ala-Tyr-Asn-Gly-Pro-Leu-Ala-NH2. This peptide, designated as Led-MNP-I, has a unique structure and does not belong to any known vertebrate or invertebrate peptide family. Two adjacent Led-MNP-I-immunoreactive perikarya were found in each optic lobe and in each half of all thoracic ganglia. Its absence from the pars intercerebralis and neurohemal organs suggests that Led-MNP-I is not a neurohormone but a neurotransmitter or neuromodulator. Treatment of isolated oviducts with varying concentrations of Led-MNP-I did not elicit significant changes in the level of cAMP concentration, suggesting that cAMP does not act as a second messenger for Led-MNP-I. Instead, Led-MNP-I induces an elevation of IP3. Treatment with Led-MNP-I did not stimulate cAMP production in the Colorado beetle brain, but this could be due to the very small number of receptive cells present. Both tissues contained a forskolin-sensitive adenylate cyclase enzyme.
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Affiliation(s)
- K Spittaels
- Zoologisch Instituut, Katholieke Universiteit Leuven, Belgium
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Sparks TC, Geng C. Analysis of the biogenic amines in the central nervous system of the tobacco hornworm by high-performance liquid chromatography with 16-sensor electrochemical detection. Anal Biochem 1992; 205:319-25. [PMID: 1443580 DOI: 10.1016/0003-2697(92)90442-a] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A method was developed to analyze biogenic amines in extracts of the central nervous system of the tobacco hornworm, Manduca sexta by high-performance liquid chromatography with 16-sensor electrochemical detection (n-EC-HPLC). The amines, precursors, and metabolites were separated in two dimensions. The first dimension involves separation based upon retention time by reversed-phase HPLC, while the second dimension involves separation based upon the characteristic oxidation potentials achieved by n-EC. Biogenic amine identification was based upon maximum oxidation potential and peak height ratios in addition to retention time. The improved resolving power of this method allows for a simplified sample preparation procedure and simultaneous determination of a wide range of compounds, including phenylethylamine, catecholamines, indoleamines, and some of their precursors and metabolites.
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Affiliation(s)
- T C Sparks
- DowElanco Discovery Research, Insect Biochemistry Laboratory, Greenfield, Indiana 46140
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Nässel DR, Meyer EP, Klemm N. Mapping and ultrastructure of serotonin-immunoreactive neurons in the optic lobes of three insect species. J Comp Neurol 1985; 232:190-204. [PMID: 3973090 DOI: 10.1002/cne.902320205] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
With antibodies to serotonin (5-HT) we have mapped immunoreactive neurons in the optic lobes of three species, the blowfly Calliphora, the desert ant Cataglyphis, and the worker bee Apis. The main emphasis in this investigation is on a system of 5-HT-positive neurons connecting the most peripheral neuropil of the optic lobes, the lamina, to more central neuropil regions. To aid in electron microscopical identification of these neurons we used immunocytochemistry at the EM-level and Golgi-EM for Calliphora and horseradish peroxidase (HRP) labelling for the other two insects. The immunoreactive terminals in Calliphora and the HRP-labelled ones in the other insects contain large (c. 100 nm) granular vesicles and smaller (c.60 nm) clear vesicles. In Cataglyphis and Apis the profiles with granular vesicles are presynaptic to second order neurons of the lamina, whereas in Calliphora no synaptic contacts were found. In this animal the 5-HT-positive terminals are situated distal to the synaptic layer of the lamina, in a region of retinal photoreceptor axons and perikarya of the lamina monopolar neurons. In Catagylphis and Apis the interactions of the 5-HT-neurons with the laminar neurons might occur through chemical synapses, whereas in Calliphora neuroactive substance could be released non-synaptically from varicosities distal to the synaptic layer. The possible involvement of 5-HT in control of neuronal activity in the optic lobes is discussed.
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