Effect of radiation on sucrose detection thresholds of mice.

Abstract

Radiotherapy is one of the most common treatments for head and neck cancers, with an almost obligate side effect of altered taste (Conger 1973). In mice, targeted irradiation of the head and neck causes transient repression of proliferation of basal epithelial cells responsible for taste cell replacement, leading to a temporary depletion of taste sensory cells within taste buds, including Type II taste cells involved in detection of sweet stimuli (Nguyen et al. 2012). These findings suggest that irradiation may elevate sucrose detection thresholds, peaking at 7 days post-irradiation when loss of Type II cells is greatest. To test this hypothesis, sucrose detection thresholds (concentration detected in 50% of presentations) were measured in mice for 15 days after treatment of: 1) irradiation while anesthetized, 2) anesthetic alone, or 3) saline. Mice were trained to distinguish water from several concentrations of sucrose. Mice were irradiated with one 8 Gy dose (RADSOURCE-2000 X-ray Irradiator) to the nose and mouth while under 2,2,2-tribromethanol anesthesia (Avertin). Unexpectedly, mice given anesthesia showed a small elevation in sucrose thresholds compared to saline-injected mice, but irradiated mice show significantly elevated sucrose thresholds compared to either control group, an effect that peaked at 6-8 days post-irradiation. The timing of loss and recovery of sucrose sensitivity generally coincides with the reported maximal reduction and recovery of Type II taste cells (Nguyen et al. 2012). Thus, even a single dose of irradiation can significantly alter detection of carbohydrates, an important consideration for patients undergoing radiotherapy.

from #ORL-AlexandrosSfakianakis via ola Kala on Inoreader http://ift.tt/2xPC5IC