Banca de QUALIFICAÇÃO: JOSÉ MÁRCIO GOMES FERNANDES

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : JOSÉ MÁRCIO GOMES FERNANDES
DATE: 16/08/2021
TIME: 09:00
LOCAL: Video Conferência Google Meet
TITLE:

BIOCHEMICAL EVALUATION OF THE INTESTINAL TUBE OF Culex quinquefasciatus AFTER EXPOSURE TO SUBLETHAL DOSE OF INSECTICIDES

KEY WORDS:

Culicidae, mosquitoes, enzymes, biochemistry, insecticides, oxidative stress.

PAGES: 80
BIG AREA: Ciências Biológicas
AREA: Bioquímica
SUMMARY:

The Culex genre has great sanitary importance in Brazil, being the transmitter of filariasis and, recently, reported as a possible transmitter of Zika Virus. Widespread throughout the country, the practice of using insecticides is the most commonly employed to control the proliferation of mosquitoes. These insecticides usually cause several damages to the animals, either in the activity of some enzymes, such as Acetylcholinesterase (AChE), or in the excessive production of Reactive Oxygen Species (ROS). Even reports of resistance are already described, often characterized by antioxidant enzymes present in these organisms, such as Superoxide Dismutase (SOD) and Catalase (CAT), which protect the animals from damage caused by ROS. Thus, the present study aimed to evaluate the biochemistry and oxidative stress of 3rd and 4th instar larvae of Cx. quinquefasciatus after exposure to a sublethal dose of the organophosphate insecticide Temephos and the Ivermectin derivative, Ivomec. For this purpose, open air tanks were set up to obtain larvae, and then they were exposed to the insecticides for evaluation of the sublethal dose. For the biochemical analysis and oxidative stress, the larval groups were exposed to the CL₅₀ of the insecticides, and later, material was prepared to evaluate the activity of the Na⁺,K⁺-ATPase (NKA) pump, the levels of GSH, Hydrogen Peroxide, Lipoperoxidation and Carbonylated Protein, the activity of the enzymes SOD and acetylcholinesterase (AChE). Here it was shown that the activity of the enzymes SOD and AChE, and the activity of NKA suffered decay when comparing the control group to the insecticide treated groups. The possibility of analyzing the decay of AChE activity is an extremely important finding, since other studies in the literature failed to observe the sensitivity of this enzyme when insecticides were applied. Also, lower levels of H₂O₂, GSH, and lipoperoxidation were quantified. This may be an indication that the mosquitoes studied here come from populations that are resistant to the insecticides used. The only indication of oxidative stress came with increased protein carbonylation in the Temephos treated individuals. This work can aid in the understanding of mosquito biology, as well as hypothesize how insecticide resistance operates in these mosquitoes, and possibly aid in future searches for new and effective ways to control these specimens.

BANKING MEMBERS:
Presidente - 1716846 - VANESSA FARIA CORTES
Externo à Instituição - LUCIANO APARECIDO MEIRELES GRILLO - UFAL
Externo à Instituição - EMERSON GUEDES PONTES - UFRRJ