Short-Term Administration of Common Anesthetics Does Not Dramatically Change the Endogenous Peptide Profile in the Rat Pituitary

Cell-cell signaling peptides (e.g., peptide hormones, neuropeptides) are among the largest class of cellular transmitters and regulate a variety of physiological processes. To identify and quantify the relative abundances of cell-cell signaling peptides in different physiological states, liquid chromatography-mass spectrometry-based peptidomics workflows are commonly utilized on freshly dissected tissues. In such animal experiments, the administration of general anesthetics is an important step for many research projects. However, acute anesthetic administration may rapidly change the measured abundance of transmitter molecules and metabolites, especially in the brain and endocrine system, which would confound experimental results. The aim of this study was to evaluate the effect of short-term (<5 min) anesthetic administration on the measured abundance of cell-cell signaling peptides, as evaluated by a typical peptidomics workflow. To accomplish this goal, we compared endogenous peptide abundances in the rat pituitary following administration of 5% isoflurane, 200 mg/kg sodium pentobarbital, or no anesthetic administration. Label-free peptidomics analysis demonstrated that acute use of isoflurane changed the levels of a small number of peptides, primarily degradation products of the hormone somatotropin, but did not influence the levels of most other peptide hormones. Acute use of sodium pentobarbital had negligible impact on the relative abundance of all measured peptides. Overall, our results suggest that anesthetics used in pituitary peptidomics studies do not dramatically confound observed results.

Automated summary

Cell-cell signaling peptides play important roles in various physiological processes, and liquid chromatography-mass spectrometry-based peptidomics workflows are commonly used to identify and quantify their relative abundances. However, acute administration of anesthetics may affect the measured abundance of cell-cell signaling peptides, especially in the brain and endocrine system. This study evaluated the effect of short-term anesthetic administration on the measured abundance of these peptides and found that isoflurane had a minor impact on the levels of some peptides, while sodium pentobarbital had negligible impact.