A rabbit model allowing access to portal vein, vena cava, aorta and duodenum without anesthesia

In studies of hepatic first-pass elimination of drugs gastric emptying, intestinal absorption and metabolism may be factors difficult to control. Direct access to the portal vein and to the duodenum without the need for anesthesia could overcome this problem. A rabbit model was, there for, developed with chronically implanted catheters in the portal vein, the aorta, the vena cava and the duodenum but necessitating a left nephrectomy. Hepatic and renal function before and 14 days after the operation showed no significant differences with respect to serum GOT, GPT, K, Na, Cl, PO4, urea-N, and creatinine levels. Arterial catheters were functioning for an average of 55, venous catheters for 49 and portal catheters for 59 days. Autopsy revealed no major pathology. This model permits the separate study of hepatic and intestinal first-pass effects in unanesthetized and unstressed rabbits.