Melatonin as protective agent for the cytotoxic effects of diazinon in the spermatogenesis in the earthworm Eisenia foetida.
Diazinon (D) is an organophosphorate synthetic insecticide widely used in the world. It inhibits acetylcholinesterase activity and damages reproduction as well as other organic functions mostly by increasing lipid peroxidation. Melatonin (M) is an indolamine secreted by the pineal gland. It performs numerous functions but recently it has been proposed as a good scavenger of oxygen radicals. The earthworm E. foetida is reputed as an excellent bioindicator of environmental chemical pollution. The testicular toxic effect of D and the protective role of M was analyzed in adult E. foetida, at 1, 7, 10, 15 and 30 days after exposure to 1/4, 1/2 and 3/4 of LD50. Sperm counts and the diameter of the seminal receptacles and of their lumina were altered in D exposed worms, which in addition have a lower percentage of survival, decreased weight and show cholinergic effect (coiling of the tail). All these changes were prevented fully or in part by simultaneous exposure to M. The observations confirm that D is a general and testicular toxicant for E. foetida, a good sentinel indicator and stresses the role of M as a protective agent.
Bustos-Obregón
E
E
Program of Morphology, ICBM, Faculty of Medicine, University of Chile, Santiago, Chile. ebustos@med.uchile.cl
González
J R
JR
Espinoza
O
O
D000818:Animals; D001681:Biological Assay; D001835:Body Weight / Q000187:drug effects / Q000502:physiology; D002800:Cholinesterase Inhibitors / Q000378:metabolism / Q000633:toxicity; D019610:Cytoprotection / Q000187:drug effects / Q000502:physiology*; D003976:Diazinon / Q000378:metabolism / Q000633:toxicity*; D004781:Environmental Exposure; D016166:Free Radical Scavengers / Q000378:metabolism; D008297:Male; D008550:Melatonin / Q000494:pharmacology*; D009068:Movement / Q000187:drug effects; D009835:Oligochaeta / Q000187:drug effects* / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology; D013076:Sperm Count; D013091:Spermatogenesis / Q000187:drug effects* / Q000502:physiology; D013094:Spermatozoa / Q000187:drug effects / Q000502:physiology; D015996:Survival Rate; D013737:Testis / Q000187:drug effects* / Q000378:metabolism
D002800:Cholinesterase Inhibitors; D016166:Free Radical Scavengers; D008550:Melatonin; D003976:Diazinon