title: Responses of PTTH-producing neurosecretory neurons in Lymantria dispar caterpillars exposed to cadmium.
abstract: Lymantria dispar, as most invasive insect species, is very adaptable and reacts quickly to changing environment. Neuroendocrine system first reacts to stress in insects, and specific neurohormonal reorganization may be used in early heavy metal risk assessment. Prothoracicotropic neurohormones (PTTH) control ecdysteroid synthesis (morphogenetic and stress hormones) in insects. In this article, we report the presence of PTTH immunoreactive molecules in L2' dorsolateral neurosecretory neurons (nsn) in caterpillar brains and changes after exposure to pollutant stress of different intensity. For 3 days, after molting into the 4th instar, caterpillars of Lymantria dispar were fed with a high wheat germ diet without (control) or with added cadmium (experimental groups: 10, 30, 100, 250 μg Cd/g dry food weight). Changes in PTTH producing L2' nsn and differences in the intensity of protein bands in the region of PTTH molecular mass (Mr 11-15 kDa) were analyzed. The number of L2' neurons tended to decrease except in the group given the highest cadmium concentration (250 μg). The neurons were enlarged after acute treatment especially in the group given the highest cadmium concentration. The size of L2' nsn nuclei was decreased only in the group fed with 30 μg Cd. Protein band intensity in the Mr region of PTTH remained unchanged in all groups except for the group given the diet with the highest Cd concentration.
authors.affiliation: Department of Insect Physiology and Biochemistry, University of Belgrade, Institute for Biological Research, Siniša Stanković, Despot Stefan Blvd.142, Belgrade 11060, Serbia.
authors.forename: Larisa
authors.initials: L
authors.lastname: Ilijin
authors.forename: Milena
authors.initials: M
authors.lastname: Vlahović
authors.forename: Marija
authors.initials: M
authors.lastname: Mrdaković
authors.forename: Dejan
authors.initials: D
authors.lastname: Mirčić
authors.forename: Dajana
authors.initials: D
authors.lastname: Todorović
authors.forename: Jelica
authors.initials: J
authors.lastname: Lazarević
authors.forename: Vesna
authors.initials: V
authors.lastname: Perić-Mataruga
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D002104:Cadmium / Q000008:administration & dosage / Q000633:toxicity*; D004032:Diet; D004785:Environmental Pollutants / Q000008:administration & dosage / Q000633:toxicity*; D007301:Insect Hormones / Q000378:metabolism*; D009036:Moths / Q000187:drug effects* / Q000502:physiology; D009474:Neurons / Q000378:metabolism; D009490:Neurosecretory Systems / Q000187:drug effects / Q000502:physiology; D013312:Stress, Physiological
chemical_list: D004785:Environmental Pollutants; D007301:Insect Hormones; D002104:Cadmium; C009089:prothoracicotropic hormone