Functional assessment of toad parotoid macroglands: A study based on poison replacement after mechanical compression

Autor(es)

Jared, Simone G. S. ^[1] ; Jared, Carlos ^[1] ; Egami, Mizue I. ^[2] ; Mailho-Fontana, Pedro L. ^[1] ; Rodrigues, Miguel T. ^[3] ; Antoniazzi, Marta M. ^[1]

Afiliação do(s) autor(es)

^[1] Inst Butantan, Lab Biol Celular, BR-05503000 Sao Paulo - Brazil

^[2] Univ Fed Sao Paulo, EPM, Dept Biol Estrutural & Func, Sao Paulo - Brazil

^[3] Univ Fed Sao Paulo, Inst Biociencias, Dept Zool, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Toxicon; v. 87, p. 92-103, SEP 2014.
• Citações Web of Science: 9

Resumo

Toads have a pair of parotoid macroglands behind the eyes that secrete poison used in passive defence against predators. These macroglands are composed of juxtaposed alveoli, each one bearing a syncytial gland, all connected to the exterior by ducts. When the parotoids are bitten, the poison is expelled on the predator oral mucosa in the form of jets, causing several pharmacological actions. After poison release, the empty secretory syncytia immediately collapse in the interior of their respective alveoli and gradually start refilling. After parotoid manual compression, simulating a predator's bite, we studied, by means of morphological methods, the replacement of the poison inside the alveoli. The results showed that after compression, a considerable number of alveoli remained intact. In the alveoli that were effectively affected the recovery occurs in different levels, from total to punctual and often restrict to some areas of the syncytia. The severely affected alveoli seem not recover their original functional state. The fact that only a part of the parotoid alveoli is compressed during an attack seems to be crucial for toad survival, since the amphibian, after being bitten by a predator, do not lose all its poison stock, remaining protected in case of new attacks. (C) 2014 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 08/57898-0 - Instituto Nacional de Ciência e Tecnologia em Toxinas
• Beneficiário: Osvaldo Augusto Brazil Esteves Sant'Anna
• Modalidade de apoio: Auxílio à Pesquisa - Temático