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Changes in cochlear blood flow due to intra-arterial infusions of angiotensin II (3-8) (angiotensin IV) in guinea pigs.
Hear Res. 1998 May; 119(1-2):61-8.HR

Abstract

The effects of a newly discovered form of angiotensin, angiotensin IV (ANGIV), on cochlear blood flow (CBF) have been investigated utilizing the laser Doppler flowmetry (LDF) technique. Two specific questions were addressed: What are the effects of anterior inferior cerebellar artery infusions (AICA) of ANGIV on CBF and do angiotensin fragments other than ANGIV influence CBF in mature male and female guinea pigs. Infusions of ANGIV, and C-terminal shortened fragments were accomplished via micropipette into the AICA and changes in CBF were observed using LDF. The results demonstrated that 10 and 100 pmol/min doses of ANGIV increased CBF 22% and 75% (n = 6; P < 0.01) from baseline, respectively, with little change in mean arterial blood pressure (MAP). Pretreatment with the ANGIV antagonist divalanal-ANGIV (1 nmole/min) blocked increases in CBF due to infusions of 100 pmol/min of ANGIV. The infusion of the C-terminal shortened fragment ANGIV(1-5) and saline had no significant effect on either CBF or MAP. These results provide the evidence for a new subtype of the angiotensin receptor and indicate the likely role of circulating hormones in blood flow regulation in the inner ear.

Authors+Show Affiliations

Kresge Hearing Research Institute, University of Michigan Medical School, Ann Arbor 48109-0506, USA.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

9641319

Citation

Coleman, J K., et al. "Changes in Cochlear Blood Flow Due to Intra-arterial Infusions of Angiotensin II (3-8) (angiotensin IV) in Guinea Pigs." Hearing Research, vol. 119, no. 1-2, 1998, pp. 61-8.
Coleman JK, Lee JI, Miller JM, et al. Changes in cochlear blood flow due to intra-arterial infusions of angiotensin II (3-8) (angiotensin IV) in guinea pigs. Hear Res. 1998;119(1-2):61-8.
Coleman, J. K., Lee, J. I., Miller, J. M., & Nuttall, A. L. (1998). Changes in cochlear blood flow due to intra-arterial infusions of angiotensin II (3-8) (angiotensin IV) in guinea pigs. Hearing Research, 119(1-2), 61-8.
Coleman JK, et al. Changes in Cochlear Blood Flow Due to Intra-arterial Infusions of Angiotensin II (3-8) (angiotensin IV) in Guinea Pigs. Hear Res. 1998;119(1-2):61-8. PubMed PMID: 9641319.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Changes in cochlear blood flow due to intra-arterial infusions of angiotensin II (3-8) (angiotensin IV) in guinea pigs. AU - Coleman,J K, AU - Lee,J I, AU - Miller,J M, AU - Nuttall,A L, PY - 1998/6/26/pubmed PY - 1998/6/26/medline PY - 1998/6/26/entrez SP - 61 EP - 8 JF - Hearing research JO - Hear Res VL - 119 IS - 1-2 N2 - The effects of a newly discovered form of angiotensin, angiotensin IV (ANGIV), on cochlear blood flow (CBF) have been investigated utilizing the laser Doppler flowmetry (LDF) technique. Two specific questions were addressed: What are the effects of anterior inferior cerebellar artery infusions (AICA) of ANGIV on CBF and do angiotensin fragments other than ANGIV influence CBF in mature male and female guinea pigs. Infusions of ANGIV, and C-terminal shortened fragments were accomplished via micropipette into the AICA and changes in CBF were observed using LDF. The results demonstrated that 10 and 100 pmol/min doses of ANGIV increased CBF 22% and 75% (n = 6; P < 0.01) from baseline, respectively, with little change in mean arterial blood pressure (MAP). Pretreatment with the ANGIV antagonist divalanal-ANGIV (1 nmole/min) blocked increases in CBF due to infusions of 100 pmol/min of ANGIV. The infusion of the C-terminal shortened fragment ANGIV(1-5) and saline had no significant effect on either CBF or MAP. These results provide the evidence for a new subtype of the angiotensin receptor and indicate the likely role of circulating hormones in blood flow regulation in the inner ear. SN - 0378-5955 UR - https://www.unboundmedicine.com/medline/citation/9641319/Changes_in_cochlear_blood_flow_due_to_intra_arterial_infusions_of_angiotensin_II__3_8___angiotensin_IV__in_guinea_pigs_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0378-5955(98)00038-0 DB - PRIME DP - Unbound Medicine ER -