Banca de DEFESA: HELENA RACHEL DA MOTA ARAUJO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : HELENA RACHEL DA MOTA ARAUJO
DATA : 29/06/2021
HORA: 08:00
LOCAL: https://conferenciaweb.rnp.br/webconf/andre-luis-da-cruz
TÍTULO:

Effects of transition from a fasting state to a postprandial state on the morphology and biochemistry of Boa constrictor (Serpentes, Boidae)

PALAVRAS-CHAVES:

1. Gastrointestinal tract 2. Infrequent feeding 3. Metabolism

PÁGINAS: 188
GRANDE ÁREA: Ciências Biológicas
ÁREA: Zoologia
SUBÁREA: Fisiologia dos Grupos Recentes
RESUMO:

Ambush-foraging vertebrate animals that fed infrequently present alterations considered extreme in the periods of food transition. In the organism these changes occur at different levels due to digestion and are quite evident in the organs related to the gastrointestinal tract. Considering these changes, the analyze of the morphological differences, patterns of substrate modification and issues related to mitochondrial functionality are necessary to understand aspects of the regulation of this process. From this perspective, Boa constrictor being an ambush-foraging snakes, with the ability to withstand long periods of fasting, fit as suitable models for this type of study. Thus, the following thesis aimed to analyze and relate morphological and biochemical aspects between the periods of food transition in Boa constrictor. Two experiments were realized following the standardization: (1) the boas were kept fasting for 2 months; (2) and the fed groups received an amount of food equivalent to 30% of their body mass in mice. In the first experiment (chapters 1, 2 and 3) 23 individuals of Boa constrictor, were kept fasted and subsequently divided into five treatments. The 0DPF group (days post-feeding; fasting, n = 5) was euthanized after the fasting period, while other treatments were fed and euthanized in the following times: 1DPF (n = 5), 2DPF (n = 5), 3DPF (n = 4) and 6DPF (n = 4). Blood was collected from these animals for plasma analysis, and stomach, intestine, liver, heart, lung, and kidney were removed, and their masses were determined for morphological and biochemical analyzes. The second experiment (chapter 4) the boas were divided into two treatments, fasting (control, n = 5) and 2DPF (fed, n = 4) and liver was collected, and the aspects of the mitochondrial functionality were analyzed. In the Chapter 1, masses and organ morphology changes were verified as a result of feeding after the fasting period. The results showed the relationship between the change in morphology and the periods of organ activity. In the Chapter 2, modification of energy substrates (glucose, protein, and lipid) during the food transition process and replacement of substrates of energy reserves were evaluated, also analyzing enzymes related to gluconeogenic pathway. As a result, it was observed that the B. constrictor modify and mobilize the substrates at the beginning of digestion, as well as for the maintenance of the process. In addition, in a few days already begin to replenish the glycogen stocks. In Chapter 3, the activity of enzymes related to glycolytic and oxidative pathways was analyzed, in addition to the relationship with the mitochondrial volume density in tissues. As results it was observed that the intestine has higher oxidative capacity at the beginning of the digestive process compared to the stomach and liver, while the liver seems to have greater glycolytic activity. Mitochondrial volume density did not differ between tissue treatments and did not correlate with the activity of CS. Perhaps the alteration in metabolism seen in the postprandial period may be related to mitochondrial characteristics such as shape and bioenergetics. Chapter 4 analyzed the mitochondrial functionality in the liver of boas considering fasting and fed treatments. The results showed an increase in mitochondrial functionality in the fed group, which is in accordance with the increase in metabolic rate after feeding in these animals, previously known in the literature. In addition, boas’ mitochondria seem adapted to fasting period, when compare your functionality basal values with mammals (mice and rat). Thus, this study broadens the understanding of the processes related to feeding in snakes, from an integrative approach, relating patterns of modification of energetic substrates considering biochemistry and morphology, in different stages of digestion. At the same time, it combined these results with the regulation of enzymes associated with substrate and energy production pathways. Finally, we analyzed a new aspect in this transition period, related to mitochondrial morphofunctionality in snakes.

MEMBROS DA BANCA:
Presidente - 1852987 - ANDRE LUIS DA CRUZ
Externa ao Programa - 6282820 - MARIA DE FATIMA DIAS COSTA
Externo à Instituição - LUIZ HENRIQUE FLORINDO - UNESP
Externa à Instituição - KÊNIA CARDOSO BÍCEGO - UNESP
Externo à Instituição - FERNANDO RIBEIRO GOMES - USP