What is the clinical evidence from this study?

Study design: Other. Intervention: Isoproterenol vs. Without exposure / before exposure. Primary outcome: betaAR-mediated inotropic response (LVDP and dP/dt(max)).

What does this research mean for the field?

Sustained exposure to isoproterenol significantly attenuates subsequent beta-adrenergic receptor-mediated inotropic responses and increases inhibitory G protein in adult rabbit hearts, whereas neonatal hearts are relatively resistant to this desensitization. Novelty: ClaimNovelty.INCREMENTAL. Consensus alignment: ConsensusAlignment.NEUTRAL.

January 1, 1999Neonatology

Regulation of Myocardial β-Adrenergic Receptor Function in Adult and Neonatal Rabbits

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Key result

Sustained isoproterenol blunts subsequent betaAR-mediated inotropic responses in adult rabbit hearts more than neonatal hearts.

Why the study?

Developmental differences in myocardial beta-adrenergic receptor desensitization and regulation in immature hearts are not well understood.

Population

Adult and neonatal rabbit hearts and ventricular tissues

Comparison

Sustained exposure to 1 microM isoproterenol vs no exposure

Design

Preclinical isolated heart preparation and biochemical assays

Authors

LSLena S. SunCreighton University

Discussion

Member takes

Implication

May indicate lower neonatal susceptibility to betaAR desensitization; leaves open translation to human infants or clinical beta-agonist use.

Structured PICO

Population

Adult and neonatal rabbits (isolated heart preparation and ventricular tissues)

Intervention

Sustained exposure to 1 microM isoproterenol

Comparator

Without exposure to isoproterenol

Outcome

betaAR-mediated inotropic response (isovolumic left ventricular developed pressure [LVDP] and maximal positive dP/dt of LVDP [dP/dt(max)])surrogate

There are significant developmental differences in myocardial beta-adrenergic receptor desensitization, with adult rabbit hearts showing greater attenuation of inotropic response following sustained isoproterenol exposure compared to neonates.

Cite This Study

Lena S. Sun (1999) studied this question. Isoproterenol vs. Without exposure / before exposure was evaluated on betaAR-mediated inotropic response (LVDP and dP/dt(max)). Sustained exposure to isoproterenol significantly attenuated subsequent betaAR-mediated inotropic responses in adult rabbit hearts, but much less so in neonatal hearts.

synapsesocial.com/papers/6ab0ae44c94af5db5b7f79db https://doi.org/10.1159/000014157

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Implication

May indicate lower neonatal susceptibility to betaAR desensitization; leaves open translation to human infants or clinical beta-agonist use.

Regulation of Myocardial β-Adrenergic Receptor Function in Adult and Neonatal Rabbits

Discussion

Member takes

Implication

Structured PICO

Cite This Study

Regulation of Myocardial β-Adrenergic Receptor Function in Adult and Neonatal Rabbits

Discussion

Member takes

Implication

Structured PICO

Cite This Study

Also Consider

Also Consider