Hemodynamic and autonomic response to acute hemorrhage in streptozotocin-induced diabetic ratsReport as inadecuate




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Cardiovascular Diabetology

, 9:78

First Online: 25 November 2010Received: 21 September 2010Accepted: 25 November 2010

Abstract

BackgroundThe various autonomic control systems lead to characteristic changes in heart rate HR and blood pressure BP during acute hemorrhage. However, cardiovascular autonomic neuropathy due to diabetes mellitus may interfere with the normal compensation for hemorrhage.

Materials and methodsA controlled graded bleeding 6 - 36% loss of estimated total blood volume: ETBV was performed in streptozotocin-induced diabetic rats STZ rats under a conscious state. Hemodynamic and autonomic responses to acute hemorrhage were examined using analysis of BP-HR variability. The effects of dextran treatment after hemorrhage were also examined.

ResultsA significant reduction in mean arterial pressure began at 12% ETBV loss in STZ rats and 18% in the control rats, respectively. When blood loss reached 18% of TEBV, the decrease in HR was prominent in STD rats due to the activation of a parasympathetic drive, as indicated by the increase in high frequency HF; 0.75~3.0 Hz power in HR variability, while in the control rats this response was not observed. The administration of dextran prevented the activation of the parasympathetic drive in STZ rats during hemorrhaging. In the control rats, the dextran treatment sustained the initial increase in HR with reduced HF power in HR variability.

ConclusionSTZ rats showed different hemodynamic and autonomic responses to acute hemorrhage from the control rats. STZ rats were prone to develop bradycardiac hypotension characterized by marked parasympathetic activation during hemorrhaging. This finding suggests enhancement of the Bezold-Jarisch reflex in STZ rats. Dextran treatment to maintain a normovolemic hemorrhage state inhibits this reflex.

AbbreviationsBPBlood pressure

B-J reflexBezold-Jarisch reflex

BRSBaroreflex Sensitivity

CANCardiovasucular Autonomic Neuropathy

ETBVEstimated Total Blood Volume

HFHigh Frequency

HRHeart Rate

HR-HFThe HF component of HR

HR-LF-HFThe ratio of LF to HF in HR

LFLow Frequency

MAPMean Arterial Pressure

SBPSystolic Blood Pressure

SBP-LFThe LF component of SBP

STZ-ratsStreptozotocin-induced diabetic rats

Electronic supplementary materialThe online version of this article doi:10.1186-1475-2840-9-78 contains supplementary material, which is available to authorized users.

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Author: Aiji Boku - Mitsutaka Sugimura - Yoshinari Morimoto - Hiroshi Hanamoto - Hitoshi Niwa

Source: https://link.springer.com/article/10.1186/1475-2840-9-78







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