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| Author(s): |
Renato Duarte Alvisi
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Medicina Veterinária e Zootecnia (FMVZ/SBD) |
| Defense date: | 2013-08-26 |
| Examining board members: |
Luciano Freitas Felicio;
Jackson Cioni Bittencourt;
Paulo César Maiorka
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| Advisor: | Luciano Freitas Felicio |
| Abstract | |
Melanin-Concentrating Hormone (MCH) has been largely implicated in the control of food intake, body weight and energy homeostasis. Moreover, lactation is an important physiological model to study hypothalamic integration to peripheral sensory signals, such as suckling stimulus and also those related to energy balance. Higher concentrations of MCH mRNA have been found during lactation in the medial preoptic area (MPOA) and in the anterior part of the paraventricular nucleus of hypothalamus, especially around the 19th day of lactation when this hormone reveals its highest peak of mRNA expression, and decrease after weaning. The physiological significance of this phenomenon is unclear. In this sense, the aim of the present study was to contribute to the investigation of sensory and endocrine factors influencing in the expression of MCH and its relationship to neuroendocrine and behavioural changes involving the end of lactation, weaning and perpetuating reproductive cycle. Wistar female rats (n= 56), divided in subgroups of four animals, were sacrificed every day from 15th to 21st day of lactation, with (CS) or without (SS) suckling stimulus. MCH and Fos immunoreactivity (MCH/Fos) was evaluated in the lateral hypothalamic area (LHA), MPOA and incerto-hypothalamic area (IHy). The MPOA showed an inverse relationship between Fos and MCH. Also, we observed an increase in the Fos of the group CS, which was less intense on 18th day when compared to 15th day, while MCH was increased. Besides, no colocalization between MCH and Fos was found. Our results suggest that suckling stimulus is able to influence the MCH around the 19th day of lactation in LHA. Therefore, the areas were we found Fos might have stimulated MCH-producing neurons. Hence, an indirect relationship between the areas of neuronal activation and MCH during suckling stimulus seems likely. (AU) | |
| FAPESP's process: | 10/14469-2 - Endocrine and functional aspects of Melanin-concentrating hormone (MCH) expression during lactation. |
| Grantee: | Renato Duarte Alvisi |
| Support Opportunities: | Scholarships in Brazil - Master |