caa a22 4500 475848543 CHVBK 20180406123921.0 cr unu---uuuuu 170329e20000801xx s 000 0 eng 10.1007/s004050000252 doi (NATIONALLICENCE)springer-10.1007/s004050000252 Preventive magnesium supplement reduces ischemia-induced hearing loss and blood viscosity in the guinea pig [Elektronische Daten] [F. Scheibe, H. Haupt, G. A. Vlastos] The effect of magnesium (Mg) on ischemia-induced hearing loss was investigated in two groups of adult pigmented guinea pigs of either an optimal or suboptimal (physiologically high or low) Mg status maintained by different diets. Total Mg concentrations of the perilymph, cerebrospinal fluid, blood plasma and red blood cells were found to differ significantly between the two groups, as tested in a previous study. Local vascular impairment was produced by unilateral ferromagnetic thrombosis of cochlear blood vessels. Cochlear blood flow (CBF) and hearing function were measured using laser Doppler flowmetry and auditory brain-stem response audiometry, respectively. Ferromagnetic thrombosis resulted in significant reductions of the mean apical CBF in both experimental groups and of the mean basal CBF in the low Mg group compared to the contralateral ears. In the high Mg group, the basal CBF was not decreased. However, the laser Doppler signals revealed considerable interindividual variations and the differences found between the two experimental groups were not significant. In contrast, the hearing loss in the low Mg group was significantly higher than that in the high Mg group. A correlation was found to exist between the vascular impairment and the hearing threshold shift. In a separate series, we also tested the effect of Mg on hemorheology and found both the blood viscosity and blood viscoelasticity to be significantly lower in the high Mg group than in the low Mg group, depending on the shear rates tested. The present findings show that a preventive oral Mg supplement can significantly reduce the rate of ischemia-induced hearing loss and improve blood viscosity in the guinea pig. Springer-Verlag Berlin Heidelberg, 2000 Key words Magnesium supplement nationallicence Cochlear thrombosis nationallicence Hearing loss nationallicence Hemorheology nationallicence Guinea pig nationallicence Scheibe F. Department of Otorhinolaryngology, Charité Hospital, Humboldt University, Schumannstrasse 20-21, 10117 Berlin, Germany e-mail: fred.scheibe@charite.de Tel.: +49-30-28022764, Fax: +49-30-28024088, DE aut Haupt H. Department of Otorhinolaryngology, Charité Hospital, Humboldt University, Schumannstrasse 20-21, 10117 Berlin, Germany e-mail: fred.scheibe@charite.de Tel.: +49-30-28022764, Fax: +49-30-28024088, DE aut Vlastos G. A. Emory University School of Medicine, Division of Cardiology, 1639 Pierce Drive, Suite 319 WMB, Atlanta, GA 30322, USA, US aut https://doi.org/10.1007/s004050000252 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s004050000252 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Scheibe F. Department of Otorhinolaryngology, Charité Hospital, Humboldt University, Schumannstrasse 20-21, 10117 Berlin, Germany e-mail: fred.scheibe@charite.de Tel.: +49-30-28022764, Fax: +49-30-28024088, DE aut NATIONALLICENCE 700 1- Haupt H. Department of Otorhinolaryngology, Charité Hospital, Humboldt University, Schumannstrasse 20-21, 10117 Berlin, Germany e-mail: fred.scheibe@charite.de Tel.: +49-30-28022764, Fax: +49-30-28024088, DE aut NATIONALLICENCE 700 1- Vlastos G. A. Emory University School of Medicine, Division of Cardiology, 1639 Pierce Drive, Suite 319 WMB, Atlanta, GA 30322, USA, US aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer