Role of Brain and Peripheral Angiotensin II in Hypertension and Altered Arterial Baroreflex Programmed during Fetal Life in Rat
| Autor: | Anne Monique Nuyt, Daniel Abran, Ngoc Loan Oanh Le, Isabelle Lahaie, Gilles Cambonie, Patrick Pladys, Gaétan Thibault |
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| Rok vydání: | 2004 |
| Předmět: |
Male
medicine.medical_specialty Offspring Angiotensin-Converting Enzyme Inhibitors Blood Pressure Baroreflex Receptor Angiotensin Type 1 Renin-Angiotensin System Fetus Pregnancy Protein Deficiency Internal medicine Renin–angiotensin system medicine Animals Rats Wistar Angiotensin II receptor type 1 business.industry Angiotensin II Brain Subfornical organ Rats Blood pressure medicine.anatomical_structure Losartan Endocrinology Enalaprilat Hypertension Pediatrics Perinatology and Child Health Female Dietary Proteins business medicine.drug |
| Zdroj: | Pediatric Research. 55:1042-1049 |
| ISSN: | 1530-0447 0031-3998 |
| DOI: | 10.1203/01.pdr.0000127012.37315.36 |
| Popis: | Intrauterine programming of hypertension is associated with evidence of increased renin-angiotensin system (RAS) activity. The current study was undertaken to investigate whether arterial baroreflex and blood pressure variability are altered in a model of in utero programming of hypertension secondary to isocaloric protein deprivation and whether activation of the RAS plays a role in this alteration. Pregnant Wistar rats were fed a normal-protein (18%) or low-protein (9%) diet during gestation, which had no effect on litter size, birth weight, or pup survival. Mean arterial blood pressure (MABP; 126 +/- 3 mm Hg 9% versus 108 +/- 4 mm Hg 18%; p0.05) and blood pressure variability were significantly greater in the adult offspring of the 9% protein-fed mothers. Arterial baroreflex control of heart rate, generated by graded i.v. infusion of phenylephrine and nitroprusside, was significantly shifted toward higher pressure; i.v. angiotensin-converting enzyme inhibitor normalized MABP and shifted the arterial baroreflex curve of the 9% offspring toward lower pressure without affecting the 18% offspring. For examining whether brain RAS is also involved in programming of hypertension, angiotensin-converting enzyme inhibitor and losartan (specific AT(1) receptor antagonist) were administered intracerebroventricularly; both significantly reduced MABP of the 9% but not the 18% offspring. Autoradiographic receptor binding studies demonstrated an increase in brain AT(1) expression in the subfornical organ and the vascular organ of the lamina terminalis in the 9% offspring. These data demonstrate a major tonic role of brain and peripheral RAS on hypertension associated with antenatal nutrient deprivation. |
| Databáze: | OpenAIRE |
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