Effects of estrogen therapy on hearing in postmenopausal women

Kılıçdağ, Esra Bulgan; Yavûz, Halûk; Bağış, Tayfun; Tarım, Ebru; Erkan, Alper Nabi; Kazanci, Ferah

doi:10.1016/j.ajog.2003.06.001

Cited by 95 publications

(87 citation statements)

References 22 publications

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“…Studies with atorvastatin-treated mice have shown decreased expression of intercellular and vascular adhesion molecules in the aortic wall, suggesting that reducing endothelial inflammatory effects may contribute to improved hair cell function by influencing the blood supply to the inner ear (Syka et al 2007). A similar paradox was found for estrogens, which have been suggested by many to have favorable vascular effects that are protective of hearing (Kilicdag et al 2004;Hultcrantz et al 2006); estradiol valerate was identified in our study as being ototoxic to hair cells of the zebrafish lateral line. Whether any protective effects of simvastatin or estrogen will exceed the potential ototoxic effects on hair cells is unknown, and testing in vivo in a mammalian model is needed to provide further insight into this question.…”

Section: Some Drugs May Have Both Protective and Toxic Effectsmentioning

confidence: 86%

Using the Zebrafish Lateral Line to Screen for Ototoxicity

Chiu

Cunningham

Raible

et al. 2008

JARO

178

134

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The zebrafish is a valuable model for studying hair cell development, structure, genetics, and behavior. Zebrafish and other aquatic vertebrates have hair cells on their body surface organized into a sensory system called the lateral line. These hair cells are highly accessible and easily visualized using fluorescent dyes. Morphological and functional similarities to mammalian hair cells of the inner ear make the zebrafish a powerful preparation for studying hair cell toxicity. The ototoxic potential of drugs has historically been uncovered by anecdotal reports that have led to more formal investigation. Currently, no standard screen for ototoxicity exists in drug development. Thus, for the vast majority of Food and Drug Association (FDA)-approved drugs, the ototoxic potential remains unknown. In this study, we used 5-day-old zebrafish larvae to screen a library of 1,040 FDA-approved drugs and bioactives (NINDS Custom Collection II) for ototoxic effects in hair cells of the lateral line. Hair cell nuclei were selectively labeled using a fluorescent vital dye. For the initial screen, fish were exposed to drugs from the library at a 100-μM concentration for 1 h in 96-well tissue culture plates. Hair cell viability was assessed in vivo using fluorescence microscopy. One thousand forty drugs were rapidly screened for ototoxic effects. Seven known ototoxic drugs included in the library, including neomycin and cisplatin, were positively identified using these methods, as proof of concept.Fourteen compounds without previously known ototoxicity were discovered to be selectively toxic to hair cells. Dose-response curves for all 21 ototoxic compounds were determined by quantifying hair cell survival as a function of drug concentration. Dose-response relationships in the mammalian inner ear for two of the compounds without known ototoxicity, pentamidine isethionate and propantheline bromide, were then examined using in vitro preparations of the adult mouse utricle. Significant dose-dependent hair cell loss in the mouse utricle was demonstrated for both compounds. This study represents an important step in validating the use of the zebrafish lateral line as a screening tool for the identification of potentially ototoxic drugs.

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Section: Some Drugs May Have Both Protective and Toxic Effectsmentioning

confidence: 86%

Using the Zebrafish Lateral Line to Screen for Ototoxicity

Chiu

Cunningham

Raible

et al. 2008

JARO

178

134

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“…Moreover, WLs and IPLs of shorter values have been shown during the periovular phase with respect to the luteal phase and follicular phase for WL I and IPLs I-V in ABR in premenopausal women before and after taking oral contraceptives [14]. Estrogen treatment in postmenopausal has been shown to be associated with women showed slowing down of hearing loss in aging postmenopausal women [26].…”

Section: Discussionmentioning

confidence: 99%

Pre- and Postovulatory Auditory Brainstem Response in Normal Women

Upadhayay

Paudel

Singh

et al. 2011

Indian J Otolaryngol Head Neck Surg

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Studies with ovarian hormones on auditory brainstem response (ABR) have conflicting reports although women have ABR shorter than men. This study compared ABR between pre-and postovulatory phases of menstrual cycle in consenting 40 healthy female volunteers (age 19 ± 2.35 years). The study was conducted under standard laboratory conditions (room temperature 26 ± 2°C) using Neuropack (Nihon Kohden machine, NM-420S; H636, Japan) and earphone dynamic receiver ELEGA (Type DR-531; no.237, Japan) in sound proof room. Ears were stimulated simultaneously using standard protocol. ABR was recorded in pre-and postovulatory phases. Ovulation was estimated by measuring basal body temperature. The ABR wave latencies (WLs) I, II, III, IV, V and inter-peak latencies (IPLs) I-III, III-V, I-V were compared between the two phases of menstrual cycle using paired t test. The postovulatory phase had shorter WL V (5.71 ± 0.18 ms vs. 5.81 ± 0.19 ms, p \ 0.01), IPL III-V (1.89 ± 0.16 ms vs. 1.94 ± 0.19 ms, p \ 0.05), and I-V (3.88 ± 0.16 ms vs. 3.95 ± 0.18 ms, p \ 0.05) than in preovulatory. Other WLs and IPLs showed decreasing trend in postovulatory phase. ABR is better in postovulatory phase as compared to preovulatory phase probably due to progesterone hormone which might be involved in modulating auditory hearing pathway at postovulatory phase.

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“…For example, human females have enhanced auditory brainstem response performance over males (Don et al, 1993;Jerger and Hall, 1980), but both sexes show marked deficits with increasing age (Jerger and Hall, 1980) that can be slowed with estrogen treatment in postmenopausal women (Kilicdag et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

Seasonal plasticity of auditory hair cell frequency sensitivity correlates with plasma steroid levels in vocal fish

Rohmann

Bass

2011

Journal of Experimental Biology

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SUMMARYVertebrates displaying seasonal shifts in reproductive behavior provide the opportunity to investigate bidirectional plasticity in sensory function. The midshipman teleost fish exhibits steroid-dependent plasticity in frequency encoding by eighth nerve auditory afferents. In this study, evoked potentials were recorded in vivo from the saccule, the main auditory division of the inner ear of most teleosts, to test the hypothesis that males and females exhibit seasonal changes in hair cell physiology in relation to seasonal changes in plasma levels of steroids. Thresholds across the predominant frequency range of natural vocalizations were significantly less in both sexes in reproductive compared with non-reproductive conditions, with differences greatest at frequencies corresponding to call upper harmonics. A subset of non-reproductive males exhibiting an intermediate saccular phenotype had elevated testosterone levels, supporting the hypothesis that rising steroid levels induce non-reproductive to reproductive transitions in saccular physiology. We propose that elevated levels of steroids act via long-term (days to weeks) signaling pathways to upregulate ion channel expression generating higher resonant frequencies characteristic of nonmammalian auditory hair cells, thereby lowering acoustic thresholds.

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Effects of estrogen therapy on hearing in postmenopausal women

Cited by 95 publications

References 22 publications

Using the Zebrafish Lateral Line to Screen for Ototoxicity

Using the Zebrafish Lateral Line to Screen for Ototoxicity

Pre- and Postovulatory Auditory Brainstem Response in Normal Women

Seasonal plasticity of auditory hair cell frequency sensitivity correlates with plasma steroid levels in vocal fish

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