Summary. A system is described for the continuous measurement of blood pressure, heart rate and motor activity by telemetry in conscious marmosets freely ...
Measurement of blood pressure and heart rate by telemetry in conscious unrestrained marmosets Christian R. Schnell & Jeanette M. Wood Cardiovascular Research Department,
Ciba-Geigy, CH-4002, Basel, Switzerland
Summary
A system is described for the continuous measurement of blood pressure, heart rate and motor activity by telemetry in conscious marmosets freely moving in their home cages. Consistent diurnal variations in these parameters were observed under standard conditions. However these parameters were sensitive to changes in the environment. Blood pressure values were similar to those measured by non-telemetric methods in conscious restrained marmosets while heart rate values were significantly lower. Keywords
Primate; Callithrix jacchu8; chronic monitoring; diurnal
Common marmosets (Collithrix ;occhus)
mean arterial pressure (MAP), heart rate
have become increasingly popular as non-
(HR) and motor activity (ACT) of
human primate models in many areas of biomedical research. They offer many advantages in that they are small, easy to handle and breed prolifically in captivity (Deinhardt et 01. 1967). Blood pressure measurements have been made in the marmoset using techniques developed for the rat such as the indirect tail-cuff method (Wood et 01. 1987) or directly via catheters implanted in an artery (Michel et 01. 1984). Marmosets are, however, highly active animals and very sensitive to restraint or repeated instrumentation. Recently, a miniaturized telemetry system for measuring blood pressure, heart rate and motor activity has been developed for use in rats (Brockway et 01. 1991). We have adapted this system for the continuous recording of the same parameters in freely moving, unrestrained marmosets in their home cages. We have used our telemetry system to investigate the basal diurnal rhythms of
marmosets and the influence of environmental conditions on these parameters.
Based on presentation during XlV Congress of the International Primatologieal Society in Strasbourg, France, August 1992
Materials and methods The common marmosets (C. ;occhus, CibaGeigy, Sisseln, Switzerland) used in this study were adults (4-7 years old) of both sexes weighing approximately 350 g. The telemetry system (Data Sciences, Inc., St Paul, Minnesota) used in our station consists of 4 basic components: an implantable transmitter [AM unit, model TAllPA-C40) which continuously senses and transmits information from within the animals, a receiver located within the cage, a matrix interface for coordination of signals from several cages and a computer based data acquisition system for collection, analyses and storage of data. The BP and HR signals are transmitted to a receiver located within the cage which detects the radio waves and reconstructs the original amplified signal. ACT is measured using the variability of the received signal strength as a result of Laboratory Animals (1995) 29. 258-261
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