Blood sampling from the ovarian vein in the unstressed pregnant guinea pig

A new technique is described which allows sampling of blood from the ovarian vein in the pregnant guinea pig, after recovery from surgery and anesthesia. The technique involves retrograde insertion of a double catheter into the thoracic inferior vena cava from the right jugular vein. The outer catheter serves as a guide for the inner catheter which is advanced into either ovarian vein. The overall rate of success was 45% in 40 animals near term. Sampling of blood from the ovarian vein in the conscious animal remained possible for up to 17 days after surgery. Since in the pregnant guinea pig the ovarian veins drain most of the uteroplacental blood, the technique of retrograde cannulation of the ovarian vein allows study of uteroplacental metabolism in the conscious pregnant animal during prolonged periods.