title: Increased sympathetic activity in normotensive offspring of malignant  hypertensive parents compared to offspring of normotensive parents.
abstract: Malignant hypertension seems to be the consequence of very high blood pressure. Furthermore, an increase in sympathetic and renin-angiotensin system activity is considered to be the main mechanisms producing malignant hypertension. In the present study, 10 offspring of malignant hypertensive (OMH) parents (age 28 +/- 5 years, 7 males, 3 females, 2 white and 8 non-white) and 10 offspring of normotensive (ONT) parents (age 28 +/- 6 years, 2 males, 8 females, 3 white and 7 non-white) were evaluated. The OMH group had significantly higher (P < 0.05) casual blood pressure (125 +/- 10/81 +/- 5 mmHg) compared with ONT (99 +/- 13/67 +/- 5 mmHg). The increase in blood pressure was greater in OMH (Delta SBP = 17 +/- 2 vs Delta SBP = 9 +/- 1 mmHg in ONT) during cold pressor testing, but they had a lower increase in heart rate (Delta HR = 13 +/- 2 vs Delta HR = 20 +/- 3 bpm in ONT) during isometric exercise(handgrip test). Sympathetic activity, measured by microneurography, was significantly higher (P < 0.05) before exercise in OMH (17 +/- 6 vs 11 +/- 4 burst/min in ONT) and exhibited a greater increase (Delta = 18 +/- 10 vs Delta = 8 +/- 3 burst/min in ONT) during isometric exercise. This study showed increased sympathetic activity in OMH before exercise and a greater response during isometric exercise, suggesting an autonomic abnormality before exercise and a greater sympathetic response to physical stress in OMH compared to ONT.
authors.affiliation: Instituto do Coração, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brasil.
authors.forename: H F
authors.initials: HF
authors.lastname: Lopes
authors.forename: F M
authors.initials: FM
authors.lastname: Consolim-Colombo
authors.forename: J A S
authors.initials: JA
authors.lastname: Barreto-Filho
authors.forename: G M G
authors.initials: GM
authors.lastname: Riccio
authors.forename: C E
authors.initials: CE
authors.lastname: Negrão
authors.forename: E M
authors.initials: EM
authors.lastname: Krieger
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D015444:Exercise / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D006974:Hypertension, Malignant / Q000097:blood / Q000235:genetics / Q000503:physiopathology*; D008297:Male; D010290:Parents; D013312:Stress, Physiological / Q000502:physiology*; D013564:Sympathetic Nervous System / Q000503:physiopathology*