Citocinas pró inflamatórias, eixo hipotálamo-hipófiseadrenal e papel do BDNFna mediação da neurogênese hipocampal no infarto do miocárdio em ratos

Abstract

Myocardial infarction (MI) is the most prevalent nowadays syndrome. Similarly impressive, depression has caused many damages to health and the global economy. Epidemiologically, these different clinical conditions have a bidirectional relationship. Several studies in rats, in recent years, associated the emergence of analog signals depression post pathophysiological IM changes, among which the activation of pro-inflammatory factors and the activation of the hypothalamic-pituitary-adrenal endocrine axis (HPA). The objective of this study was: to study, in different rat groups, a short-term protocol, four days and a long, twenty-five days, the above features, besides elucidating the involvement of brain-derived neurotrophic factor (BDNF ) and hippocampal neurogenesis in the onset of depression induced experimental IM by ki-67 protein, cell proliferation marker. For this purpose, male Wistar rats (200-250 g) were subjected to IM through ligation of the left coronary artery and underwent preference for sucrose test and the open field test. They were measured: cardiac TNF-α, plasma and hypothalamic concentrations of TNF-α and IL-1β. In endocrine handle, plasma concentrations of adrenocorticotropic hormone (ACTH) and corticosterone and hypothalamic levels of corticotropin releasing hormone (CRH). Finally, we measured plasma concentrations of BDNF to the association with the neurogenesis of the hippocampus, an important region in the pathophysiology of depression. In the long protocol, infarcted animals showed similar signs of depression compared to those operated fake animals. Concomitantly, showed elevated levels of TNF-α and IL-1β, CRH, ACTH and corticosterone plasma levels and reduced BDNF, suggesting decreased proliferation of granule cells in the hippocampus and hence the emergence of depression in response to MI. Although further studies are required, it is believed that this study has translational impact serving experimental basis for the development of more effective future pharmacologic strategies to better quality and life expectancy of patients with myocardial infarction.