title: Adrenergic ligands that block oviposition in the cattle tick Rhipicephalus microplus affect ovary contraction.
abstract: The tyraminergic/octopaminergic system is central for the control of arthropod oviposition. Previous works demonstrated that the pharmacological perturbation of this system inhibits oviposition in the cattle tick Rhipicephalus microplus. In this work, we describe a physiologically active whole-mount preparation of the contractile tick ovary that allows the quantitative videometrical analysis of ovary contraction in response to different compounds. Eight adrenergic ligands known to inhibit oviposition, including octopamine and tyramine were tested. These compounds exhibited antagonistic effects; octopamine relaxes the ovary preparation while tyramine induces a very strong contraction. The other adrenergic compounds tested were classified as able to contract or relax ovary muscle tissue. Isoprotenerol has a stronger relaxative effect than octopamine. Tyramine induces the biggest contraction observed of all the compounds tested, followed, in descending amount of contraction, by salbutamol, prazosin, epinastine, clonidine and the acaricide amitraz. The effect of these adrenergic ligands on the ovary preparation, explains why these molecules inhibit tick oviposition and suggest a regulatory mechanism for ovary contraction and relaxation during oviposition. Our results also provide a physiological explanation of the egg-laying inhibition effect of amitraz when used on the cattle tick.
authors.affiliation: Centro Nacional de Investigación Disciplinaria en Parasitología Veterinaria, Instituto Nacional de Investigaciones Forestales Agrícolas y Pecuarias INIFAP. Carr. Fed. Cuernavaca-Cuautla No. 8534, Jiutepec, Morelos, México, 62550.
authors.forename: Raquel
authors.initials: R
authors.lastname: Cossío-Bayúgar
authors.affiliation: Centro Nacional de Investigación Disciplinaria en Parasitología Veterinaria, Instituto Nacional de Investigaciones Forestales Agrícolas y Pecuarias INIFAP. Carr. Fed. Cuernavaca-Cuautla No. 8534, Jiutepec, Morelos, México, 62550.
authors.forename: Estefan
authors.initials: E
authors.lastname: Miranda-Miranda
authors.affiliation: Centro Nacional de Investigación Disciplinaria en Parasitología Veterinaria, Instituto Nacional de Investigaciones Forestales Agrícolas y Pecuarias INIFAP. Carr. Fed. Cuernavaca-Cuautla No. 8534, Jiutepec, Morelos, México, 62550.
authors.forename: Manuel
authors.initials: M
authors.lastname: Fernández-Rubalcaba
authors.affiliation: Centro de Investigación en Dinámica Celular, Universidad Autónoma del Estado de Morelos Av. Universidad 1001, Col. Chamilpa, Cuernavaca Morelos, México, 62209.
authors.forename: Verónica
authors.initials: V
authors.lastname: Narváez Padilla
authors.affiliation: Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad, 2001, Apartado Postal 510-3, Cuernavaca, Morelos, México, 62210.
authors.forename: Enrique
authors.initials: E
authors.lastname: Reynaud
mesh_terms: D056810:Acaricides / Q000494:pharmacology*; D018663:Adrenergic Agents / Q000494:pharmacology*; D000420:Albuterol / Q000494:pharmacology; D000818:Animals; D002417:Cattle; D003000:Clonidine / Q000494:pharmacology; D003984:Dibenzazepines / Q000494:pharmacology; D005260:Female; D007093:Imidazoles / Q000494:pharmacology; D007545:Isoproterenol / Q000494:pharmacology; D009655:Octopamine / Q000494:pharmacology; D010053:Ovary / Q000187:drug effects* / Q000502:physiology; D010058:Oviposition / Q000187:drug effects* / Q000502:physiology; D011224:Prazosin / Q000494:pharmacology; D048494:Rhipicephalus / Q000187:drug effects* / Q000502:physiology; D046509:Tissue Culture Techniques; D014052:Toluidines / Q000494:pharmacology; D014439:Tyramine / Q000494:pharmacology; D014741:Video Recording
chemical_list: D056810:Acaricides; D018663:Adrenergic Agents; D003984:Dibenzazepines; D007093:Imidazoles; D014052:Toluidines; D009655:Octopamine; C014983:amitraz; D007545:Isoproterenol; D003000:Clonidine; C053090:epinastine; D000420:Albuterol; D014439:Tyramine; D011224:Prazosin