Banca de QUALIFICAÇÃO: MARIA VANESSA DA SILVA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : MARIA VANESSA DA SILVA
DATE: 25/09/2025
TIME: 08:00
LOCAL: Google meet
TITLE:

INVESTIGATION OF THE PROTECTIVE EFFECT OF MELATONIN ON THE PERIOD OF FETAL ORGANOGENESIS IN RATS EXPOSED TO CHRONIC ALCOHOL CONSUMPTION

KEY WORDS:

Morphogenesis; rats, immunohistochemistry, oxidative stress; ethanol; pineal; pregnancy

PAGES: 67
BIG AREA: Ciências Biológicas
AREA: Morfologia
SUBÁREA: Histologia
SUMMARY:

Alcohol consumption during pregnancy can cause a wide range of cognitive, behavioral, and emotional deficits, in addition to promoting congenital anomalies. It easily crosses the placenta, disrupts maternal metabolic pathways, and impairs the development of vital fetal organs such as the brain, liver, and kidneys, resulting in neurodegeneration, liver fibrosis, and a reduction in nephron count, respectively. Melatonin has demonstrated beneficial effects on brain, liver, and kidney damage. Although there is significant evidence regarding the detrimental effects of alcohol consumption during pregnancy on fetal health, there are still gaps in knowledge regarding which specific period of organogenesis is most vulnerable to the effects of this substance. Thus, in this study, we aim to evaluate during which period of brain, liver, and kidney organogenesis in rat offspring alcohol consumption during pregnancy is most deleterious, and whether melatonin can prevent these effects. Thirty 90-day-old virgin albino Wistar rats, weighing approximately 250g, were used for this study. These rats were obtained from the Animal Facility of the Department of Animal Morphology and Physiology at the Federal Rural University of Pernambuco (UFRPE). The animals were divided into six experimental groups: Control - rats not exposed to alcohol and euthanized on E15 and E19 (days 15 and 19 of gestation, respectively); Alcohol - rats subjected to chronic alcohol consumption and euthanized on E15 and E19 (days 15 and 19 of gestation, respectively); Alcohol + Melatonin - Rats subjected to chronic alcohol consumption and euthanized on E15 and E19 (15th and 19th days of gestation, respectively). Alcohol was administered by intragastric gavage at a dose of 3 g/kg, and melatonin was administered by daily injections at a dose of 0.8 mg/kg. Analysis of weights and lengths at E15 and E19 in the alcohol group revealed a significant reduction in dam weight, fetal weight, and length compared to the control and alcohol + melatonin groups. Our study found structural disorganization of the cerebral mesenchyme, which can be identified by changes in the estimated external, borderline, and internal density of the neuroepithelium and by the reduced volume of the telencephalon in the alcohol group at E15 and E19. We also observed a decrease in neuroepithelium thickness at E15, persisting at E19, in the alcohol group, compared to the other groups. Furthermore, at E15, incorrect formation of the telencephalon molecular layer was observed, and at E19, reduced development of the telencephalon ventricles in the alcohol group compared to the other groups. Our findings indicate increased levels of pro-inflammatory cytokines, both IL-6 and TNFα, from E15 to E19 in the alcohol group compared to the other groups. We also observed increased apoptotic cell staining in the alcohol group at E15 and E19, compared to the other experimental groups. Regarding PCNA staining, we observed that the alcohol group had lower cell proliferation at E15 and E19, compared to the other groups. As a partial conclusion, we found that melatonin has great therapeutic potential for preventing the changes caused by chronic alcohol consumption during fetal neurogenesis.

 

COMMITTEE MEMBERS:
Presidente - VALERIA WANDERLEY TEIXEIRA
Interno - EMMANUEL VIANA PONTUAL
Externa à Instituição - ISMAELA MARIA FERREIRA DE MELO
Externo à Instituição - JAIURTE GOMES MARTINS DA SILVA