angiotensin-i and Starvation

We previously showed that 2 weeks of a severe food restricted (sFR) diet (40% of the caloric intake of the control (CT) diet) up-regulated the circulating renin angiotensin (Ang) system (RAS) in female Fischer rats, most likely as a result of the fall in plasma volume. In this study, we investigated the role of the central RAS in the mean arterial pressure (MAP) and heart rate (HR) dysregulation associated with sFR. Although sFR reduced basal mean MAP and HR, the magnitude of the pressor response to intracerebroventricular (icv) microinjection of Ang-[1-8] was not affected; however, HR was 57 ± 13 bpm lower 26 min after Ang-[1-8] microinjection in the sFR rats and a similar response was observed after losartan was microinjected. The major catabolic pathway of Ang-[1-8] in the hypothalamus was via Ang-[1-7]; however, no differences were detected in the rate of Ang-[1-8] synthesis or degradation between CT and sFR animals. While sFR had no effect on the AT

Topics: Angiotensin I; Angiotensin II; Angiotensin II Type 1 Receptor Blockers; Angiotensin-Converting Enzyme 2; Animals; Arterial Pressure; Autoradiography; Caloric Restriction; Female; Heart Rate; Hypothalamus; Injections, Intraventricular; Losartan; Organum Vasculosum; Paraventricular Hypothalamic Nucleus; Peptide Fragments; Peptidyl-Dipeptidase A; Preoptic Area; Rats; Rats, Inbred F344; Receptor, Angiotensin, Type 1; Renin-Angiotensin System; Starvation; Subfornical Organ