Meeting Abstract

P2.123  Jan. 5  Influence of anesthesia methods on steroid levels in amphibians WIDDER, P. D.**; HUSAK, J. F.; MOORE, I. T.; BELDEN, L. K.; Virginia Tech widder@vt.edu

Few studies have examined the influence of anesthesia on steroid levels in amphibians, and these studies have been limited to the stress hormone corticosterone. However, if one aims to examine steroid levels and/or relate traits to those hormone levels, it is important to know if anesthetic agents cause changes in hormone levels or otherwise interfere with measurements of these hormones. In amphibians, approved anesthetics can take anywhere from a few minutes to more than a half an hour to produce the desired amount of sedation, while stress hormones can be detectably elevated in as little as 3 minutes. This leads to the question of whether anesthetics work quickly enough to prevent handling induced elevations in corticosterone. We used radioimmunoassay methods to examine how the use of two common and readily available anesthetics for amphibian ecological studies, MS-222 and 20% benzocaine, influenced testosterone, estradiol and corticosterone levels. We compare these to initial hormone levels (within 3 minutes) and levels after 30 minutes of restraint in wood frog, Rana sylvatica, tadpoles and red backed salamander, Plethodon cinereus, adults.