Biomedical subjects

Lea Delbridge

Publications and source records attributed to Lea Delbridge.

3 recordsLinked to original sources

PubMed2002

Low doses of angiotensin converting enzyme inhibitors and angiotensin type 1 blockers have a synergistic effect but high doses are less than additive.

BACKGROUND: Angiotensin converting enzyme (ACE) inhibitors and angiotensin type I (AT(1)) receptor blocking drugs block the effects of angiotensin II by different mechanisms. This study examined the effect of combination of different doses of the two drugs on blood pressure (BP). METHODS: Blood pressure was measured by telemetry in spontaneous hypertensive rats (SHRs) and the acute response to losartan (L), captopril (C), or their combination in equal amounts was measured for doses of 0, 1.25, 2.5, 5, 10, 20, and 40 mg/kg. RESULTS: The effect of the combination of low doses of the two drugs was more than additive (synergistic) with 80% of the full response achieved with L-2.5 + C-2.5. In higher doses the response was less than additive, but a greater decrease (P <.01) in systolic BP (44.6 +/- 2.5 mm Hg) was achieved with the combination than with captopril (37.1 +/- 2.7 mm Hg), which was greater (P <.05) than with losartan (32.9 +/- 2.4 mm Hg). CONCLUSIONS: The interaction between ACE inhibitors and AT(1) blockers depends on the dose used, but the combination has greater BP-lowering effects than either drug as monotherapy.

Angiotensin-Converting Enzyme Inhibitors↗

PubMed2002

Evolution of a student model-building program.

We describe the design and development of a highly interactive model-building program to assist students from a diverse range of academic backgrounds to understand the baroreceptor reflex. Our approach is to have students work in small groups to construct their own simple model of such a control system. This model then provides the basis for a structural framework for students to add further complexity without losing overall perspective and allows exploration of deeper issues. Our program is suitable for many disciplines and student backgrounds and provides a visual representation of a difficult concept, providing a basis to ground further knowledge. Audit trail data have been analyzed to identify and resolve areas of student difficulty, and extensive surveys and observations on students' use of the program over three years in several courses have been used to test and improve its effectiveness.

Baroreflex↗

PubMed2002

Interaction of ACE inhibitors and AT(1)-receptor blockers on maximum blood pressure response in spontaneous hypertensive rats.

This study in spontaneous hypertensive rats (SHR) was designed to determine whether a greater fall in blood pressure (BP) could be achieved with the combination of an angiotensin-converting enzyme inhibitor (ACE-I) and an AT(1)-receptor blocking drug than with higher doses of either drug alone. The peak effect of captopril occurred 3 4 hours post-dose and a plateau response was achieved with 10 mg/kg. The peak effect of losartan occurred 7 8 hours post-dose and a plateau response was achieved with 10 mg/kg. Increasing the dose of either drug caused no greater fall in BP, but increased the duration of the effect. Captopril, 10 mg/kg, administered with losartan 10 mg/kg caused a greater fall in BP than captopril or losartan, 20 mg/kg. This was present after acute doses or after one week of daily therapy. The combination of ACE-I and AT(1)-blocking drugs is more effective than either therapy alone and may be a useful combination to manage hypertension and/or cardiac failure.

Angiotensin Receptor Antagonists↗