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Effects of central metformin administration on responses to air-jet stress and on arterial baroreflex function in spontaneously hypertensive rats.
J Hypertens. 1997 Mar; 15(3):285-91.JH

Abstract

OBJECTIVE

To examine effects of intracerebroventricular (ICV) administration of metformin on the responses to environmental stress and on arterial baroreflex function in conscious spontaneously hypertensive rats (SHR).

METHODS

SHR were instrumented with an ICV cannula and prepared for measurements of the mean arterial pressure (MAP), heart rate, and renal sympathetic nerve activity (RSNA) during air-jet stress (AJS). After recovery from a pretreatment AJS period, rats were allocated randomly to ICV administration of either vehicle (saline; n = 9) or 1 mg metformin (which is inactive dose after intravenous administration; n = 8). After stabilization for 1 h, the AJS was repeated. The arterial baroreflex control of the heart rate and RSNA was examined at the end of the experiment.

RESULTS

ICV metformin decreased the baseline heart rate (by 88+/-14 beats/min) and RSNA (by 19+/-8%) in the absence of changes in MAP. ICV vehicle did not affect responses to the AJS [change in MAP (deltaMAP) = +11+/-2 mmHg, change in heart rate (deltaHR) = +54+/-9 beats/min, change in RSNA (deltaRSNA) = +37+/-8%), but pressor, tachycardic, and renal sympathoexcitatory responses to the AJS were inhibited significantly by ICV metformin (deltaMAP = +4+/-3 mmHg, deltaHR = -5+/-5 beats/min; deltaRSNA = +11+/-3%). ICV metformin did not affect the arterial baroreflex range, but it did increase the maximal gain of the arterial baroreflex control of heart rate (-1.46+/-0.25 versus 0.67+/-0.13%/mmHg, P= 0.01) and RSNA (-5.04+/-1.10 versus -2.47+/-0.28%/mmHg, P = 0.053).

CONCLUSIONS

Central metformin administration attenuated the renal sympathoexcitatory response to environmental stress and increased the gain of the arterial baroreflex control of heart rate and RSNA. These actions may contribute to the antihypertensive effect of metformin.

Authors+Show Affiliations

Department of Pharmacology, The Panum Institute, University of Copenhagen, Denmark.No affiliation info available

Pub Type(s)

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

Language

eng

PubMed ID

9468456

Citation

Petersen, J S., and G F. DiBona. "Effects of Central Metformin Administration On Responses to Air-jet Stress and On Arterial Baroreflex Function in Spontaneously Hypertensive Rats." Journal of Hypertension, vol. 15, no. 3, 1997, pp. 285-91.
Petersen JS, DiBona GF. Effects of central metformin administration on responses to air-jet stress and on arterial baroreflex function in spontaneously hypertensive rats. J Hypertens. 1997;15(3):285-91.
Petersen, J. S., & DiBona, G. F. (1997). Effects of central metformin administration on responses to air-jet stress and on arterial baroreflex function in spontaneously hypertensive rats. Journal of Hypertension, 15(3), 285-91.
Petersen JS, DiBona GF. Effects of Central Metformin Administration On Responses to Air-jet Stress and On Arterial Baroreflex Function in Spontaneously Hypertensive Rats. J Hypertens. 1997;15(3):285-91. PubMed PMID: 9468456.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Effects of central metformin administration on responses to air-jet stress and on arterial baroreflex function in spontaneously hypertensive rats. AU - Petersen,J S, AU - DiBona,G F, PY - 1997/3/1/pubmed PY - 1998/2/19/medline PY - 1997/3/1/entrez SP - 285 EP - 91 JF - Journal of hypertension JO - J. Hypertens. VL - 15 IS - 3 N2 - OBJECTIVE: To examine effects of intracerebroventricular (ICV) administration of metformin on the responses to environmental stress and on arterial baroreflex function in conscious spontaneously hypertensive rats (SHR). METHODS: SHR were instrumented with an ICV cannula and prepared for measurements of the mean arterial pressure (MAP), heart rate, and renal sympathetic nerve activity (RSNA) during air-jet stress (AJS). After recovery from a pretreatment AJS period, rats were allocated randomly to ICV administration of either vehicle (saline; n = 9) or 1 mg metformin (which is inactive dose after intravenous administration; n = 8). After stabilization for 1 h, the AJS was repeated. The arterial baroreflex control of the heart rate and RSNA was examined at the end of the experiment. RESULTS: ICV metformin decreased the baseline heart rate (by 88+/-14 beats/min) and RSNA (by 19+/-8%) in the absence of changes in MAP. ICV vehicle did not affect responses to the AJS [change in MAP (deltaMAP) = +11+/-2 mmHg, change in heart rate (deltaHR) = +54+/-9 beats/min, change in RSNA (deltaRSNA) = +37+/-8%), but pressor, tachycardic, and renal sympathoexcitatory responses to the AJS were inhibited significantly by ICV metformin (deltaMAP = +4+/-3 mmHg, deltaHR = -5+/-5 beats/min; deltaRSNA = +11+/-3%). ICV metformin did not affect the arterial baroreflex range, but it did increase the maximal gain of the arterial baroreflex control of heart rate (-1.46+/-0.25 versus 0.67+/-0.13%/mmHg, P= 0.01) and RSNA (-5.04+/-1.10 versus -2.47+/-0.28%/mmHg, P = 0.053). CONCLUSIONS: Central metformin administration attenuated the renal sympathoexcitatory response to environmental stress and increased the gain of the arterial baroreflex control of heart rate and RSNA. These actions may contribute to the antihypertensive effect of metformin. SN - 0263-6352 UR - https://www.unboundmedicine.com/medline/citation/9468456/Effects_of_central_metformin_administration_on_responses_to_air_jet_stress_and_on_arterial_baroreflex_function_in_spontaneously_hypertensive_rats_ L2 - http://dx.doi.org/10.1097/00004872-199715030-00010 DB - PRIME DP - Unbound Medicine ER -