LEONARDO JENSEN SOCAS
Projetos de Pesquisa
Unidades Organizacionais
LIM/59 - Laboratório de Biologia Celular, Hospital das Clínicas, Faculdade de Medicina
2 resultados
Resultados de Busca
Agora exibindo 1 - 2 de 2
- Blood-brain barrier lesion-a novel determinant of autonomic imbalance in heart failure and the effects of exercise training(2023) RAQUEL, Hiviny de Ataides; PEREGO, Sany M.; MASSON, Gustavo S.; JENSEN, Leonardo; COLQUHOUN, Alison; MICHELINI, Lisete C.Heart failure (HF) is characterized by reduced ventricular function, compensatory activa-tion of neurohormonal mechanisms and marked autonomic imbalance. Exercise training (T) is effective to reduce neurohormonal activation but the mechanism underlying the au-tonomic dysfunction remains elusive. Knowing that blood-brain barrier (BBB) lesion con-tributes to autonomic imbalance, we sought now to investigate its involvement in HF-and exercise-induced changes of autonomic control. Wistar rats submitted to coronary artery ligation or SHAM surgery were assigned to T or sedentary (S) protocol for 8 weeks. After hemodynamic/autonomic recordings and evaluation of BBB permeability, brains were har-vesting for ultrastructural analysis of BBB constituents, measurement of vesicles trafficking and tight junction's (TJ) tightness across the BBB (transmission electron microscopy) and caveolin-1 and claudin-5 immunofluorescence within autonomic brain areas. HF-S rats ver-sus SHAM-S exhibited reduced blood pressure, augmented vasomotor sympathetic activity, increased pressure and reduced heart rate variability, and, depressed reflex sensitivity. HF-S also presented increased caveolin-1 expression, augmented vesicle trafficking and a weak TJ (reduced TJ extension/capillary border), which determined increased BBB permeability. In contrast, exercise restored BBB permeability, reduced caveolin-1 content, normalized vesicles counting/capillary, augmented claudin-5 expression, increased TJ tightness and selectivity simultaneously with the normalization of both blood pressure and autonomic bal-ance. Data indicate that BBB dysfunction within autonomic nuclei (increased transcytosis and weak TJ allowing entrance of plasma constituents into the brain parenchyma) underlies the autonomic imbalance in HF. Data also disclose that exercise training corrects both tran-scytosis and paracellular transport and improves autonomic control even in the persistence of cardiac dysfunction.
- Postprandial increase in glucagon-like peptide-1 is blunted in severe heart failure(2020) ARRUDA-JUNIOR, Daniel F.; MARTINS, Flavia L.; SALLES, Thiago Almeida; JENSEN, Leonardo; DARIOLLI, Rafael; ANTONIO, Ednei L.; SANTOS, Leonardo dos; CRAJOINAS, Renato O.; TUCCI, Paulo J. F.; GOWDAK, Luis Henrique W.; KRIEGER, Jose Eduardo; PEREIRA, Alexandre C.; GIRARDI, Adriana C.The relationship between disturbances in glucose homeostasis and heart failure (HF) progression is bidirectional. However, the mechanisms by which HF intrinsically impairs glucose homeostasis remain unknown. The present study tested the hypothesis that the bioavailability of intact glucagon-like peptide-1 (GLP-1) is affected in HF, possibly contributing to disturbed glucose homeostasis. Serum concentrations of total and intact GLP-1 and insulin were measured after an overnight fast and 15 min after the ingestion of a mixed breakfast meal in 49 non-diabetic patients with severe HF and 40 healthy control subjects. Similarly, fasting and postprandial serum concentrations of these hormones were determined in sham-operated rats, and rats with HF treated with an inhibitor of the GLP-1-degrading enzyme dipeptidyl peptidase-4 (DPP4), vildagliptin, or vehicle for 4 weeks. We found that HF patients displayed a much lower increase in postprandial intact and total GLP-1 levels than controls. The increase in postprandial intact GLP-1 in HF patients correlated negatively with serum brain natriuretic peptide levels and DPP4 activity and positively with the glomerular filtration rate. Likewise, the postprandial increases in both intact and total GLP-1 were blunted in HF rats and were restored by DPP4 inhibition. Additionally, vehicle-treated HF rats displayed glucose intolerance and hyperinsulinemia, whereas normal glucose homeostasis was observed in vildagliptin-treated HF rats. We conclude that the postprandial increase in GLP-1 is blunted in non-diabetic HF. Impaired GLP-1 bioavailability after meal intake correlates with poor prognostic factors and may contribute to the establishment of a vicious cycle between glucose disturbance and HF development and progression.