The common marmoset has been used in a wide range of toxicological research and as a model for human disease and physiology, including cardiovascular research.
However, due to small body size and high heart rate, the generation of data on non-invasive blood pressure measurements in unsedated marmosets were somehow arbitrary; therefore the non-invasive, accurate determination of blood pressure in this species represents a challenge. A former in-house study rejected normal oscillometry as numerous recordings failed or were not reproducible (mean artery blood pressure (MAP) ranged between 26 and 171 mmHg). The high-definition oscillometry (HDO) technique allows visible, real-time control of each measurement on a screen by the use of blood pressure amplitude scans with up to 16.000 Hz within 10 to 15 s. HDO was used in 18 marmosets to determine the systolic (SYS) and diastolic (DIA) blood pressure, MAP, and the pulse/min. In conscious animals, these parameters were determined between 2 to 4 times, depending on the animal’s compliance.
Ten min after intramuscular injection of ketamine (50 mg/kg), diazepam (0.5 mg/kg), and glycopyrrolate (0.008 mg/kg), the above-mentioned parameters were determined 7 times per individual. Results in conscious marmosets: mean SYS: 142.3 mmHg (standard deviation [SD] 13.2); mean DIA: 64.3 mmHg (SD 7.6); mean MAP: 91.6 mmHg (SD 8.3); pulse/min: 390.7 (SD 41.9). The intraindividual SD ranged as follows: SYS: SD 2 to 13 (mean 7); DIA: SD 1 to 16 (mean 4.2), mean MAP: SD 1 to 15 (mean 4.2). After a first increase in pulse rate directly after induction of anaesthesia, a decrease of SYS, DIA, MAP and the pulse rate was determined in regard to unsedated common marmosets. Results in sedated marmosets: mean SYS: 93.9 mmHg (SD 12.4); mean DIA: 46.3 mmHg (SD 6.9); mean MAP: 63.4 mmHg (SD 8.4); pulse/min: 340.2 (SD 26.0). The intraindividual SD under sedation was even decreased. The MAPs in conscious marmosets determined in this study correspond to those gained by implantable telemetry (MAP 95 mmHg, SD 9) or by indwelling arterial catheters (MAP 107 mmHg, SD 16). Our results demonstrate the feasibility of non-invasive blood ressure measurements by HDO technique in common marmosets, whether conscious or sedated.