Technical note: An improved surgical model for the long-term studies of kinetics and quantification of nutrient absorption in swine1,2

Abstract

An improved technique to study kinetics and quantitative absorption of nutrients in pigs is described. Three female pigs (35 kg of BW) were surgically modified with catheters in the hepatic portal vein and carotid artery and an ultrasonic flow probe around the portal vein. Catheter placement and patency was secured using distal modifications (rings and holes) and nonabsorbable suture. Catheters and flow probe cable were tunneled subcutaneously after exteriorization for further protection. Fibrosis and adhesions in the body cavity were minimized by avoiding excessive manipulation and drying of viscera. Pigs were supported during recovery by intravenous fluid therapy of AA and electrolytes until regular feeding resumed. Catheters were flushed daily with heparinized saline (200 IU/L). After 10 d, pigs were fed a diet based on wheat and soybean meal for 6 consecutive 7-d periods. On d 7, blood was collected postprandially every 15 min from -15 to 60 min, 30 to 240 min, 60 to 480 min, and 120 to 720 min. Blood flow was measured simultaneously. Plasma was analyzed for glucose, and net glucose absorption was calculated from plasma portal-arterial differences x plasma flow [blood flow x (1 - hematocrit)]. The specific improvements for long-term use of this model are distal modifications of the catheters, postoperative treatment using parental nutrition and gut motility drug, prevention of infection of body cavity by further tunneling of catheters and blood flow probe cable, and use of ultrasonic blood flow probes and meter. Blood flow measurements using an ultrasonic blood flow probe was not changed after 52 d compared with 10 d post-surgery, indicating the reliability of this model. This catheterized pig model, thus, will allow the long-term study of the kinetics of nutrient absorption.

Minimally-invasive catheterization of portal and mesenteric veins and abdominal aorta for quantitative determination of portal-drained viscera metabolism in pigs

“…Similar results were reported after conventional catheterization, ranging from 6 to 12 wk (Yen and Killefer 1987;Leeuwen et al 1995;Hooda et al 2009;Rodríguez-lópez et al 2013). Occlusion of implanted catheters is a common problem in multicatheterized pigs used for studies.…”

“…Multiple abdominal intravascular catheterization in pigs is also a common surgical procedure and an important research tool in animal nutrition (Bajjalieh et al 1981;Olesen et al 1989;Stoll et al 1998;Yen et al 2004;Hooda et al 2009). Studies used pigs with multiple indwelling catheters implanted in portal, hepatic, and mesenteric veins as well as an artery (carotid artery or abdominal aorta), and the placement of indwelling catheters into abdominal blood vessels was carried out commonly through celiotomy (Yen and Killefer 1987;Stoll et al 1998;Yen et al 2004;Hooda et al 2009;Rodríguez-lópez et al 2013).…”

Bioavailability of vitamin B12 in cows' milk

“…Average body weight at surgery was 48·7 (SEM 1·0) kg. The surgery procedure has been described by Hooda et al (21) . Briefly, the animals were equipped with an ultrasonic flow probe (14 mm flow probe, SB-series: Transonic Systems, Inc., Ithaca, NY, USA) around the portal vein and a catheter inside the portal vein at 3·5 and 2·5 cm before its entry into the liver, respectively.…”

Classical and post-genomic methods to study GIT function with emphasis on the pig

“…Pigs are implanted with cannulas in the portal vein and carotid artery (for blood withdrawal), a jugular vein (for i.v. tracer infusion), and a PBF probe (Hooda et al, 2009). Further, gastric or duodenal cannulas (for enteral tracer infusion) ensure a controlled enteral nutrient and tracer intake.…”

“…This requires the implantation of portal vein and carotid artery catheters and a portal blood flow probe (Stoll et al, 1998;Hooda et al, 2009). Upon initiation of enteral nutrient administration net portal nutrient balance is calculated by the difference of the nutrient concentration [C] in the portal (port) and arterial (art) blood multiplied by the portal blood flow (PBF).…”