Use of Micropipette-Guided Drug Administration as an Alternative Method to Oral Gavage in Rodent Models

Abstract

Oral gavage (OG) with the use of a cannula attached to a syringe is one of the most common methods used to deliver precise dosing of compounds to the stomach of research animals. Unfortunately, this method comes with difficulties for both the operator and the research animal. Studies have shown that OG may lead to complications, including esophagitis, perforation of the esophagus, and inadvertent tracheal drug administration. In addition, OG is associated with increased plasma and fecal corticosterone levels (due to stress), altered blood pressure, and increased heart rate, which could negatively influence or bias study results. A previously developed alternative method termed micropipette-guided drug administration (MDA) incentivizes the animal to consume treatments readily in a minimally invasive manner. Herein, we present examples of the use of the MDA technique with treatments reconstituted in different vehicles and demonstrate effective delivery of the varied treatments to multiple different mouse strains. We further demonstrate that MDA is a technique that decreases the timing and invasiveness of drug administration and does not affect the gut microbiome composition as assessed by quantitative analysis of core gut microbial species. Overall, MDA may offer a less stressful and effective alternative to OG.