Rapid effects of aldosterone in primary cultures of cardiomyocytes - do they suggest the existence of a membrane-bound receptor?

Aldosterone acts on its target tissue through a classical mechanism or through the rapid pathway through a putative membrane-bound receptor. Our goal here was to better understand the molecular and biochemical rapid mechanisms responsible for aldosterone-induced cardiomyocyte hypertrophy. We have evaluated the hypertrophic process through the levels of ANP, which was confirmed by the analysis of the superficial area of cardiomyocytes. Aldosterone increased the levels of ANP and the cellular area of the cardiomyocytes; spironolactone reduced the aldosterone-increased ANP level and cellular area of cardiomyocytes. Aldosterone or spironolactone alone did not increase the level of cyclic 3',5'-adenosine monophosphate (cAMP), but aldosterone plus spironolactone led to increased cAMP level; the treatment with aldosterone + spironolactone + BAPTA-AM reduced the levels of cAMP. These data suggest that aldosterone-induced cAMP increase is independent of mineralocorticoid receptor (MR) and dependent on Ca(2+). Next, we have evaluated the role of A-kinase anchor proteins (AKAP) in the aldosterone-induced hypertrophic response. We have found that St-Ht31 (AKAP inhibitor) reduced the increased level of ANP which was induced by aldosterone; in addition, we have found an increase on protein kinase C (PKC) and extracellular signal-regulated kinase 5 (ERK5) activity when cells were treated with aldosterone alone, spironolactone alone and with a combination of both. Our data suggest that PKC could be responsible for ERK5 aldosterone-induced phosphorylation. Our study suggests that the aldosterone through its rapid effects promotes a hypertrophic response in cardiomyocytes that is controlled by an AKAP, being dependent on ERK5 and PKC, but not on cAMP/cAMP-dependent protein kinase signaling pathways. Lastly, we provide evidence that the targeting of AKAPs could be relevant in patients with aldosterone-induced cardiac hypertrophy and heart failure.

Determinacao do perfil dos usuarios e da composicao quimica e nutricional da alimentacao oferecida no restaurante universitario da Universidade Estadual Paulista, Araquara, Brasil / Determination of the user's profile and of the chemical and nutricional composition of the meals offered at the university restaurant of the Universidade Estadual Paulista, Araraquara, Brazil

Este estudo teve como objetivos determinar o perfil e o estado nutricional das refeicoes oferecidas no restaurante universitario da Universidade Estadual Paulista de Araraquara, Brasil. Realizou-se a determinacao quimica do teor de proteinas, lipidios, carboidratos, fibra, cinzas e umidade de amostras das refeicoes fornecidas. A amostra populacional foi constituido de 403 usuarios (212 mulheres e 191 homens). Em relacao ao perfil do usuario, constatou-se que 82,60 por cento encontravam-se na faixa etaria de 18 a 25 anos e 75, 44 por cento dos individuos apresentaram indice de massa corporal dentro da faixa etaria de normalidade. Em media, as refeicoes continham 4,74 por cento de proteinas, 10,84 por cento de lipideos, 24,32 de carboidratos, 3,30 por cento de fibras, 1,00 por cento de cinzas e 55,00 por cento de umidade. Os dados mostraram que as refeicoes do restaurante universitario continham excesso de proteinas e de energia e que se faz necessario realizar ajustes na sua composicao para adequa-la ao perfil da clientela atendida