A comparison of rectal and subcutaneous body temperature measurement in the common marmoset

Two methods of measuring body temperature were compared in common marmosets. Subcutaneous temperatures were measured remotely via previously implanted subcutaneous microchips (Plexx BV, IPTT-100) prior to measurement of rectal temperature using a conventional rectal probe. Marmosets were treated with saline or the brain penetrant, 5-HT1A/B/D receptor agonist SKF-99101H (3-(2-dimethylaminoethyl)-4-chloro-5-propoxyindole hemifumarate) (0.3-3 mg/kg SC), which has previously been shown to induce hypothermia in guinea pigs. Body temperature was sampled immediately before drug administration and at 30-min intervals thereafter for a period of 2.5 h. SKF-99101H dose-dependently induced hypothermia in the common marmoset and there was close agreement between rectal and subcutaneous body temperatures, with an average difference in absolute body temperature of 0.26+/-0.02 degrees C. The data show that subcutaneously implanted microchips provide a simple, reliable measure of body temperature in common marmosets which is sensitive to pharmacological intervention, minimizes handling induced stress, and is minimally invasive.