Aldosterone in ovine fetal circulation is mainly of fetal origin. Three of the renin-angiotensin system (RAS) parameters (renin, renin substrate and angiotensin II) originate in the fetus. The fetal RAS responds to stimulation (furosemide administration, hemorrhage, hypoxemia) or inhibition (phenylephrine or angiotensin II infusion) in a manner similar to that of the adult. The response of the ...

The beneficial effects of angiotensin converting enzyme (ACE) inhibitors in heart failure appear to be independent, at least in part, of their effect on blood pressure. The existence of a local cardiac renin angiotensin system is often suggested as an explanation. It has been known for some time that a substantial proportion of arterially delivered angiotensin I is converted to angiotensin II b...

Angiotensin II, a peptide hormone that regulates blood pressure, has been proposed as a protective factor against cerebral malaria based on a genetic analysis. In vitro studies have documented an inhibitory effect of angiotensin II on Plasmodium growth, while studies using chemical inhibitors of angiotensin II in mice showed protection against experimental cerebral malaria but not major effects...

We previously found that angiotensin II infusion into rat causes iron deposition in the kidney and heart, which may have a role in the regulation of profibrotic genes expression as well as tissue fibrosis. In the present study, we have investigated whether angiotensin II can also induce iron accumulation in the liver. Prussian blue staining detected frequent iron deposition in the interstitium ...

To examine whether hypoxia-inducible factor (HIF)-1α mediates the profibrotic effects of angiotensin II, we treated cultured renal medullary interstitial cells with angiotensin II and found that it increased HIF-1α levels. This was accompanied by a significant upregulation of collagen I/III, the tissue inhibitor of metalloproteinase-1, elevation of the proliferation marker proliferating cell nu...

We used the calcium-sensitive fluorescent indicator quin 2 to monitor changes in cytosolic free calcium concentration ([Ca2+]i) associated with angiotensin II receptor activation in cultured vascular smooth muscle cells isolated from rat aorta. Resting [Ca2+]i in unstimulated vascular smooth muscle cells was 198 +/- 7 nM. Angiotensin II induced concentration-dependent rapid increases in [Ca2+]i...

BACKGROUND Abnormal iron deposition may cause oxidant-induced damage in various organs. We have previously reported that continuous administration of angiotensin II to rats results in an overt iron deposition in the renal tubular epithelial cells, which may have a role in angiotensin II-induced renal damage. In the present study, we investigated the role of iron in the development of cardiac in...

The relative contribution of circulating versus tissue renin-angiotensin systems to the tissue expression of angiotensin peptides in the kidney remains unresolved. To address this issue, intrarenal and urinary levels of the peptide products of the renin-angiotensin system were assessed in a tissue angiotensin-converting enzyme knockout (tisACE-/-) mouse model. Systolic blood pressure was signif...

The mechanisms of drug dependence and rewarding properties of opiates are not exactly known and several neurotransmitters seem to be involved. It is possible that the rennin-angiotensin system could interact with the opioid system, since it has been shown that angiotensin II(Ang) and ACE inhibitors have analgesic, anticonvulsant and antidepression effects and in some cases they could antagonize...

Myogenic and angiotensin contractions of afferent arterioles generate reactive oxygen species. Resistance vessels express neutrophil oxidase-2 and -4. Angiotensin II activates p47(phox)/neutrophil oxidase-2, whereas it downregulates NOX-4. Therefore, we tested the hypothesis that p47(phox) enhances afferent arteriolar angiotensin contractions. Angiotensin II infusion in p47(phox) +/+ but not -/...