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Implantation of Combined Telemetric ECG and Blood Pressure Transmitters to Determine Spontaneous Baroreflex Sensitivity in Conscious Mice
Published on: February 14, 2021
Baroreflex sensitivity differs among same strain Wistar rats from the same laboratory
Vitor E Valenti1, Luiz Carlos de Abreu, Hugo Macedo Junior
1Departamento de Medicina, Disciplina de Cardiologia, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP;
Heart International
|November 4, 2011
Summary
Wistar rats exhibit significant variations in baroreflex sensitivity, impacting heart rate regulation. This study highlights the importance of considering individual differences in baroreflex function within the same rat strain.
Area of Science:
- Physiology
- Cardiovascular Research
- Animal Models
Background:
- Previous research identified variable baroreflex sensitivity in Sprague-Dawley rats.
- Baroreflex sensitivity in Wistar rats remains largely uninvestigated.
- Understanding baroreflex variability is crucial for cardiovascular research.
Purpose of the Study:
- To compare baroreflex sensitivity within a cohort of Wistar rats.
- To characterize the range of baroreflex gain in normotensive Wistar rats.
- To establish if baroreflex sensitivity varies significantly in rats from the same strain and laboratory.
Main Methods:
- Male Wistar rats (300-400g) underwent surgical implantation of arterial cannulas.
- Mean arterial pressure and heart rate were continuously monitored.
- Baroreflex sensitivity was assessed using phenylephrine (pressor) and sodium nitroprusside (depressor) challenges, calculating the heart rate change relative to mean arterial pressure change (ΔHR/ΔMAP).
Main Results:
- Approximately 71% of rats showed reduced bradycardic baroreflex gain.
- Around 50% of rats exhibited an increased tachycardic baroreflex gain.
- No significant differences were found in basal mean arterial pressure, heart rate, peak reflex responses, or heart rate range.
Conclusions:
- Significant inter-individual variability in baroreflex sensitivity exists within Wistar rats.
- These findings underscore the need to account for intrinsic baroreflex differences in experimental designs.
- Baroreflex sensitivity is not uniform even in genetically similar rats under controlled laboratory conditions.
