Abstract
Vascular changes contribute to age-related hearing loss but the mechanisms involved in microvascular reactivity, particularly in the aged ear, are still incompletely understood. In this study, possible age-related changes in cochlear blood flow (CBF) and vascular reactivity were studied in presbycusic mice (C57BL/6) and young, age-matched, and old controls (CBA/J) without presbycusis. Reactivity was monitored by laser Doppler flowmetry and assessed by change in cochlear vascular conductance (VC) (defined as the ratio of CBF to blood pressure) in response to round window-applied sodium nitroprusside, a vasodilating agent. Mean VC response of C57BL/6 mice differed from controls both in maximum response and in post-drug recovery time. In C57BL/6 mice, mean VC increased about 28%, in contrast to an increase of over 40% in young and age-matched CBA/J controls. A less elevated VC response, similar to that of the presbycusic mice, was shown by aged (20-21 month) controls. Also, VC response in C57BL/6 mice was sustained throughout the 60 min observation period, while response of most CBA/J controls recovered in 50 min or less. These changes suggest age-dependent, pathologically-related altered responsiveness in cochlear vascular reactivity.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 189-194 |
| Number of pages | 6 |
| Journal | Hearing Research |
| Volume | 86 |
| Issue number | 1-2 |
| DOIs | |
| State | Published - 1995 |
| Externally published | Yes |
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Keywords
- Laser Doppler flowmetry
- Persbycusis
- Sodium nitroprusside
ASJC Scopus subject areas
- Sensory Systems
Cite this
Age-related changes in cochlear vascular conductance in mice. / Nadine Brown, J.; Miller, Josef M.; Nuttall, Alfred.
In: Hearing Research, Vol. 86, No. 1-2, 1995, p. 189-194.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Age-related changes in cochlear vascular conductance in mice
AU - Nadine Brown, J.
AU - Miller, Josef M.
AU - Nuttall, Alfred
PY - 1995
Y1 - 1995
N2 - Vascular changes contribute to age-related hearing loss but the mechanisms involved in microvascular reactivity, particularly in the aged ear, are still incompletely understood. In this study, possible age-related changes in cochlear blood flow (CBF) and vascular reactivity were studied in presbycusic mice (C57BL/6) and young, age-matched, and old controls (CBA/J) without presbycusis. Reactivity was monitored by laser Doppler flowmetry and assessed by change in cochlear vascular conductance (VC) (defined as the ratio of CBF to blood pressure) in response to round window-applied sodium nitroprusside, a vasodilating agent. Mean VC response of C57BL/6 mice differed from controls both in maximum response and in post-drug recovery time. In C57BL/6 mice, mean VC increased about 28%, in contrast to an increase of over 40% in young and age-matched CBA/J controls. A less elevated VC response, similar to that of the presbycusic mice, was shown by aged (20-21 month) controls. Also, VC response in C57BL/6 mice was sustained throughout the 60 min observation period, while response of most CBA/J controls recovered in 50 min or less. These changes suggest age-dependent, pathologically-related altered responsiveness in cochlear vascular reactivity.
AB - Vascular changes contribute to age-related hearing loss but the mechanisms involved in microvascular reactivity, particularly in the aged ear, are still incompletely understood. In this study, possible age-related changes in cochlear blood flow (CBF) and vascular reactivity were studied in presbycusic mice (C57BL/6) and young, age-matched, and old controls (CBA/J) without presbycusis. Reactivity was monitored by laser Doppler flowmetry and assessed by change in cochlear vascular conductance (VC) (defined as the ratio of CBF to blood pressure) in response to round window-applied sodium nitroprusside, a vasodilating agent. Mean VC response of C57BL/6 mice differed from controls both in maximum response and in post-drug recovery time. In C57BL/6 mice, mean VC increased about 28%, in contrast to an increase of over 40% in young and age-matched CBA/J controls. A less elevated VC response, similar to that of the presbycusic mice, was shown by aged (20-21 month) controls. Also, VC response in C57BL/6 mice was sustained throughout the 60 min observation period, while response of most CBA/J controls recovered in 50 min or less. These changes suggest age-dependent, pathologically-related altered responsiveness in cochlear vascular reactivity.
KW - Laser Doppler flowmetry
KW - Persbycusis
KW - Sodium nitroprusside
UR - http://www.scopus.com/inward/record.url?scp=0029160274&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0029160274&partnerID=8YFLogxK
U2 - 10.1016/0378-5955(95)00070-K
DO - 10.1016/0378-5955(95)00070-K
M3 - Article
VL - 86
SP - 189
EP - 194
JO - Hearing Research
JF - Hearing Research
SN - 0378-5955
IS - 1-2
ER -