Carotid Blood Pressure in Normal and Tumor-Bearing Mice

¹ From the Laboratory of Chemical Pharmacology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland

Blood pressure was measured directly in mice after cannulation of the carotid artery. The anesthetic was urethan in a single intraperitoneal dose of 1.4–1.6 mg/gm. The apparatus was a Technitrol Lilly manometer, or a Statham physiological transducer (Model P 23 D) with a Brush ‘Universal analyzer.’ The blood pressure was continuously recorded in some 400 CAF₁ mice, both normal and bearers of Sarcoma 37. In 166 mice without tumor, the mean blood pressure varied from 35–110 mm of mercury; the average was 71 with a S.E. of ± 1. In 233 mice bearing 6-day-old implants of Sarcoma 37, the pressure varied from 40–110 mm.; the average was 78 ± 1 mm. Under these conditions of continuous recording of arterial blood pressure, about 40% of the animals lived for 2 hours; a few survived as long as 6 hours. The various patterns of blood pressure changes are described and illustrated.