Influence of aquatic contaminants in melanomacrófagos of Rhinella schneideri (Anura: Bufonidae)

• Grant number: 11/14607-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2011
• End date: October 31, 2012
• Field of knowledge: Biological Sciences - Zoology - Morphology of Recent Groups
• Principal Investigator: Classius de Oliveira
• Grantee: Juliana Ferreira Antoniassi
• Host Institution: Instituto de Biociências, Letras e Ciências Exatas (IBILCE). Universidade Estadual Paulista (UNESP). Campus de São José do Rio Preto. São José do Rio Preto , SP, Brazil

Abstract

Amphibians share with ectothermic vertebrates, the existence of an extracutaneous pigmentary system consisting of large and irregular cells in various tissues and organs, which are able to produce and store melanin inside. The functional role of these pigment cells in the organs is not well defined, with several assumptions, among them, the processes of detoxification of pollutants and cytoprotective functions related to free radicals. The melanin-containing cells are also found in bodies with hematopoietic cells, which have phagocytic activity similar to macrophages. In these organs, their function is related to phagocytosis of cellular material originating from catabolism. Given the well-known action of melanomacrófagos in the detoxification of pollutants and cytoprotective function, this paper aims to analyze the pigment in the visceral surface and within the organs, spleen, and liver of anuran Rhinella schneideri to the action of different water contaminants: Escherichia coli lipopolysaccharide and hormone 17²-estradiol, which are abundant in aquatic environments polluted due to human activities. Copies will be used 45 males of the species R. schneideri collected in permanent ponds in the region of Sao Jose do Rio Preto - SP. For hormone treatment, will receive injections of 2mg/kg on alternate days and will be reviewed after a period of 3, 7, 15, and 30 days of treatment. For the treatment with lipopolysaccharide from Escherichia coli, will receive a single dose of 3 mg/kg and will be analyzed after 2 hours and 24 hours of administration. Thus, one tries to describe the response of pigment cells to the action of different pollutants in early and late responses, and, this will be carried out morphological, quantitative, and histochemical.(AU)