title: Effect of transtympanic betamethasone delivery to the inner ear.
abstract: To investigate the effect of transtympanic betamethasone administration on hearing function with histologic correlation, rats were divided into three transtympanic treatment groups: isotonic saline (group I, n = 10), gentamicin (group II, n = 10) and betamethasone (group III, n = 10). Distortion product otoacoustic emission thresholds were compared on day 10. Also histological effects on cellular apoptosis in both the inner and outer hair cells in organ of Corti and spiral ganglion neurons were evaluated. Distortion product otoacoustic emission thresholds were comparable (p > 0.05) between group I and group III in all measurements. Distortion product otoacoustic emission thresholds of group II were significantly elevated in all measurements when compared with group I (p < 0.05) and group III (p < 0.05). In the Terminal deoxynucleotidyl transferase dUTP Nick End Labelling (TUNEL), Caspase-3, Caspase-8 and Caspase-9 staining method the amount of apoptotic cells in group II were significantly elevated in all measurements compared with group I (p < 0.05). In the TUNEL staining method the amount of apoptotic cells in Group III were significantly elevated compared with group I in both the organ of Corti and spiral ganglion neurons (p < 0.05). The overall histological results revealed that the severity of cellular apoptosis caused by betamethasone was somewhere between isotonic saline and gentamicin. Transtympanic betamethasone does not affect inner ear function as measured by distortion product otoacoustic emission responses, but some increase in cellular apoptosis in the organ of Corti and spiral ganglion neurons was observed. These findings suggest that transtympanic betamethasone may have mild ototoxic effects. Further studies are needed to obtain precise results for transtympanic application of betamethasone.
authors.affiliation: Department of Otolaryngology, Kocaeli Derince Research and Training Hospital, Kocaeli Derince Eğitim ve Araştırma Hastanesi Kulak Burun Boğaz Kliniği, 41900, Derince, Kocaeli, Turkey. heozel@yahoo.com.
authors.forename: Halil Erdem
authors.initials: HE
authors.lastname: Özel
authors.affiliation: Department of Otolaryngology, Kocaeli Derince Research and Training Hospital, Kocaeli Derince Eğitim ve Araştırma Hastanesi Kulak Burun Boğaz Kliniği, 41900, Derince, Kocaeli, Turkey.
authors.forename: Fatih
authors.initials: F
authors.lastname: Özdoğan
authors.affiliation: Department of Histology and Embryology, Celal Bayar University School of Vocational Health Service, Manisa, Turkey.
authors.forename: Seren
authors.initials: S
authors.lastname: Gülşen Gürgen
authors.affiliation: Department of Otolaryngology, Kocaeli Derince Research and Training Hospital, Kocaeli Derince Eğitim ve Araştırma Hastanesi Kulak Burun Boğaz Kliniği, 41900, Derince, Kocaeli, Turkey.
authors.forename: Erkan
authors.initials: E
authors.lastname: Esen
authors.affiliation: Department of Otolaryngology, Kocaeli Derince Research and Training Hospital, Kocaeli Derince Eğitim ve Araştırma Hastanesi Kulak Burun Boğaz Kliniği, 41900, Derince, Kocaeli, Turkey.
authors.forename: Adin
authors.initials: A
authors.lastname: Selçuk
authors.affiliation: Department of Otolaryngology, Kocaeli Derince Research and Training Hospital, Kocaeli Derince Eğitim ve Araştırma Hastanesi Kulak Burun Boğaz Kliniği, 41900, Derince, Kocaeli, Turkey.
authors.forename: Selahattin
authors.initials: S
authors.lastname: Genç
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001623:Betamethasone / Q000008:administration & dosage*; D053148:Caspase 3 / Q000378:metabolism; D053181:Caspase 8 / Q000378:metabolism; D003051:Cochlea / Q000187:drug effects / Q000201:enzymology; D007758:Ear, Inner / Q000187:drug effects* / Q000201:enzymology / Q000502:physiology; D005839:Gentamicins / Q000494:pharmacology; D005938:Glucocorticoids / Q000008:administration & dosage*; D018072:Hair Cells, Auditory, Outer / Q000187:drug effects; D020287:In Situ Nick-End Labeling; D008297:Male; D009925:Organ of Corti / Q000187:drug effects; D017084:Otoacoustic Emissions, Spontaneous / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D012684:Sensory Thresholds / Q000187:drug effects / Q000502:physiology; D013136:Spiral Ganglion / Q000187:drug effects; D014432:Tympanic Membrane
chemical_list: D005839:Gentamicins; D005938:Glucocorticoids; D001623:Betamethasone; D053148:Caspase 3; D053181:Caspase 8
keywords: Animal model; Betamethasone; Gentamicin; Hearing loss; Ototoxicity; Transtympanic treatment
references.citation: Neurosci Lett. 2000 Nov 10;294(1):21-4
references.pmid: 11044577
references.citation: Acta Otolaryngol Suppl. 2010 Nov;(563):101-4
references.pmid: 20879828
references.citation: Otol Neurotol. 2010 Apr;31(3):394-403
references.pmid: 20147868
references.citation: Clin Otolaryngol Allied Sci. 1998 Aug;23(4):360-7
references.pmid: 9762501
references.citation: Otol Neurotol. 2007 Dec;28(8):1124-30
references.pmid: 18043438
references.citation: Laryngoscope. 2012 Apr;122(4):877-82
references.pmid: 22374513
references.citation: Laryngoscope. 2012 May;122(5):1154-7
references.pmid: 22447636
references.citation: Otol Neurotol. 2008 Apr;29(3):401-6
references.pmid: 18277312
references.citation: Nanomedicine (Lond). 2010 Nov;5(9):1331-40
references.pmid: 21128717
references.citation: Laryngoscope. 2014 May;124(5):1209-13
references.pmid: 24142776