Long-Term Catheterization of the Intestinal Lymph Trunk and Collection of Lymph in Neonatal Pigs

Abstract

Catheterization of the intestinal lymph trunk in neonatal pigs is a technique allowing for the long-term collection of large quantities of intestinal (central) efferent lymph. Importantly, the collection of central lymph from the intestine enables researchers to study both the mechanisms and lipid constitutes associated with lipid metabolism, intestinal inflammation and cancer metastasis, as well as cells involved in immune function and immunosurveillance. A ventral mid-line surgical approach permits excellent surgical exposure to the cranial abdomen and relatively easy access to the intestinal lymph trunk vessel that lies near the pancreas and the right ventral segment of the portal vein underneath the visceral aspect of the right liver lobe. The vessel is meticulously dissected and released from the surrounding fascia and then dilated with sutures allowing for insertion and subsequent securing of the catheter into the vessel. The catheter is exteriorized and approximately 1 L/24 hr of lymph is collected over a 7 day period. While this technique enables the collection of large quantities of central lymph over an extended period of time, the success depends on careful surgical dissection, tissue handling and close attention to proper surgical technique. This is particularly important with surgeries in young animals as the lymph vessels can easily tear, potentially leading to surgical and experimental failure. The video demonstrates an excellent surgical technique for the collection of intestinal lymph.

An update on oral drug delivery via intestinal lymphatic transport

“…Big animals (pig, dog) are preferred to smaller ones (rat and mouse) because of physiological and anatomical keenness ( e.g. , biliary secretion) to human 266 , 267 . Moreover, it is easy to simulate pre- and post-prandial states in big animals than in small ones which display constant bile flow regardless of dietary 81 .…”

Low birth weight causes insulin resistance and aberrant intestinal lipid metabolism independent of microbiota abundance in Landrace–Large White pigs

“…At 13 wk of age (7 wk of diet), swine were unfed overnight and weighed and general anesthetic was induced. A cannula was implanted into the superior mesenteric lymph duct and lymph was collected for 1 h into an EDTA-coated Vacutainer as previously described by Uwiera et al (42). Total lymph volume as well as lymph flow rate (lymph volume per hour) was recorded and exsanguination was performed under anesthetic prior to tissue collection.…”

“…Additionally, we also found that SREBP2, INSIG1, LDL receptor, and HMGCR were all down-regulated in swine fed the Western diet. A study in hamsters reported that cholesterol feeding causes a decrease in the intestinal gene expression of HMG-CoA reductase, SREBP2, and the LDL receptor, thus leading to reduced cholesterol synthesis (39,42,60). Insig1 reciprocally controls cholesterol synthesis; however, because the ratio of SREBP cleavage-activating protein (SCAP) to Insig cumulatively regulates this process, it is difficult to infer anything just from the expression of Insig1 (61).…”

Considerations for Choosing Appropriate Animal Models to Study Inflammatory Bowel Disease

“…localization of treatments in specific locations in the small intestine). Furthermore, the collection of both intestinal and non-intestinal lymph provides insight to effects of diets, therapeutic agents, and modulators of immune function on immune surveillance and processes involved in the pathogenesis of IBD ; R. R. E. Uwiera, Mangat, Kelly, T. C. Uwiera, & Proctor, 2016). Importantly, the use of larger animal models to study IBD facilitates the collection of large quantities of tissue without pooling samples, and thereby reduces the numbers of animals required.…”