Angiotensin II type 1 receptor-mediated reduction of angiotensin-converting enzyme 2 activity in the brain impairs baroreflex function in hypertensive mice.

Angiotensin-converting enzyme 2 (ACE2), a new component of the brain renin-angiotensin system, has been suggested to participate in the central regulation of blood pressure (BP). To clarify the relationship between ACE2 and other brain renin-angiotensin system components, we hypothesized that central angiotensin II type 1 receptors reduce ACE2 expression/activity in hypertensive mice, thereby impairing baroreflex function and promoting hypertension. To test this hypothesis, chronically hypertensive mice (RA) with elevated angiotensin II levels were treated with losartan (angiotensin II type 1 receptor blocker) or PD123319 (angiotensin II type 2 antagonist; 10 mg/kg per day, SC) for 2 weeks.

Angiotensin-converting enzyme 2 overexpression in the subfornical organ prevents the angiotensin II-mediated pressor and drinking responses and is associated with angiotensin II type 1 receptor downregulation.

We recently reported the presence of angiotensin-converting enzyme (ACE)2 in brain regions controlling cardiovascular function; however, the role of ACE2 in blood pressure regulation remains unclear because of the lack of specific tools to investigate its function. We hypothesized that ACE2 could play a pivotal role in the central regulation of cardiovascular function by regulating other renin-angiotensin system components. To test this hypothesis, we generated an adenovirus expressing the human ACE2 cDNA upstream of an enhanced green fluorescent protein (eGFP) reporter gene (Ad-hACE2-eGFP).

Oropharyngeal candidiasis in HIV(+) patients may influence the selection of HIV-1 protease variants.

Approximately 500 HIV-1 protease gene (pro) sequences were obtained from oral tissues (gingival cuff, buccal mucosa, tongue, palate) as well as saliva and peripheral blood mononuclear cells (PBMC) of 80 HIV-1 positive patients by nested amplification and manual sequencing of PCR products. By visual inspection each patient in this study exhibited a unique sequence profile. HIV-1 pro sequences obtained from patients with oropharyngeal candidiasis (OPC(+) patients) had significantly higher numbers of mutations than sequences from OPC(-) patients, but OPC(+) patients were no more likely to accumulate protease inhibitor resistance mutations than OPC(-) patients.