Cardiac autonomic denervation and expression of neurotrophins (NGF and BDNF) and their receptors during experimental Chagas disease

Abstract

Although cardiac dysautonomia is a distinctive feature of Chagas disease, its clinical and functional significance is still being speculated. Neurotrophic factors are potentially involved; however, studies of their effect in this infection are rare. Ultrastructural abnormalities in autonomic varicosities, levels of both nerve growth factor (NGF), and brain-derived neurotrophic factor (BDNF), as well as the expression of their receptors, were analysed in the heart of a rat model of Trypanosoma infection. Predominantly, at the early stage of the infection, cardiac autonomic varicosities displayed several signs of degeneration parallel to the elevation of cardiac levels of NGF, as well as expression of the receptors TrkA and p75NTR. For BDNF and TrkB, the changes were less conspicuous. Data obtained here can contribute to further clarify the factors related to the autonomic nervous system’s adaptive changes that could determine the evolution of different clinical forms of Chagas disease; mainly, the cardiac form.

Keywords:

• Chagas disease
• Trypanosoma cruzi infection
• cardiac autonomic innervation
• NGF
• BDNF

Acknowledgements

The authors are grateful to the Center of Microscopy at the Universidade Federal de Minas Gerais (http://www.microscopia.ufmg.br), and to the Pró-Reitoria de Pesquisa da UFMG. We are indebted to Carlos Henrique da Silva and Afonso da Costa Viana for their technical assistance.

Disclosure statement

The authors declare no potential conflicts of interest with respect to the authorship and/or publication of this article.

Additional information

Funding

This work was supported by Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq).