title: Taurine attenuates bilirubin-induced neurotoxicity in the auditory system in neonatal guinea pigs.
abstract: OBJECTIVE
  Previous work showed that taurine protects neurons against unconjugated bilirubin (UCB)-induced neurotoxicity by maintaining intracellular calcium homeostasis, membrane integrity, and mitochondrial function, thereby preventing apoptosis from occurring, in primary neuron cultures. In this study, we investigated whether taurine could protect the auditory system against the neurotoxicity associated with hyperbilirubinemia in an in vivo model.
  
  
  METHODS
  Hyperbilirubinemia was established in neonatal guinea pigs by intraperitoneal injection of UCB. Hearing function was observed in electrocochleograms (ECochGs) and auditory brainstem responses (ABRs) recorded before and 1, 8, 24, and 72 h after UCB injection. For morphological evaluations, animals were sacrificed at 8h post-injection, and the afferent terminals beneath the inner hair cells (IHCs), spiral ganglion neurons (SGNs), and their fibers were examined.
  
  
  RESULTS
  It was found that UCB injection significantly increased latencies and inter-wave intervals, and thresholds of ABR and compound action potentials, and caused marked damage to type I SGNs, their axons, and terminals to cochlear IHCs. When baby guinea pigs were pretreated with taurine for 5 consecutive days and then injected with bilirubin, electrophysiological abnormalities and morphological damage were attenuated significantly in both the peripheral and central auditory system.
  
  
  CONCLUSIONS
  From these observations, it was concluded that taurine limited bilirubin-induced neural damage in the auditory system. These findings may contribute to the development of taurine as a broad-spectrum agent for preventing and/or treating hearing loss in neonatal jaundice.
authors.affiliation: Department of Otorhinolaryngology, Affiliated Sixth People's Hospital of Shanghai Jiaotong University, 600 Yishan Road, Shanghai 200233, China.
authors.forename: Hai-Bo
authors.initials: HB
authors.lastname: Ye
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.forename: Wei-Tian
authors.initials: WT
authors.lastname: Zhang
authors.forename: Hai-Bo
authors.initials: HB
authors.lastname: Shi
authors.forename: Shan-Kai
authors.initials: SK
authors.lastname: Yin
mesh_terms: D000818:Animals; D001300:Audiometry, Evoked Response; D001663:Bilirubin / Q000494:pharmacology; D016057:Evoked Potentials, Auditory, Brain Stem; D006168:Guinea Pigs; D006199:Hair Cells, Auditory, Inner / Q000187:drug effects*; D006801:Humans; D006932:Hyperbilirubinemia / Q000150:complications* / Q000188:drug therapy; D007231:Infant, Newborn; D009474:Neurons / Q000187:drug effects*; D020258:Neurotoxicity Syndromes / Q000188:drug therapy*; D013654:Taurine / Q000008:administration & dosage*
chemical_list: D013654:Taurine; D001663:Bilirubin