What is the clinical evidence from this study?

Study design: Other. Intervention: alpha 1-adrenergic receptor agonist phenylephrine vs. control. Primary outcome: velocity of unloaded shortening (Vo).

What does this research mean for the field?

Alpha 1-adrenergic receptor stimulation significantly decreases the maximum shortening velocity of skinned single ventricular myocytes, indicating an inhibition of the cross-bridge cycling rate at the myofilament level. Novelty: ClaimNovelty.NOVEL_FINDING. Consensus alignment: ConsensusAlignment.NEUTRAL.

What question did this study set out to answer?

To determine whether alpha-1 adrenergic receptor stimulation directly reduces the maximum shortening velocity of single skinned rat ventricular myocytes.

July 1, 1995Circulation Research

α 1 -Adrenergic Receptor Stimulation Decreases Maximum Shortening Velocity of Skinned Single Ventricular Myocytes From Rats

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Key result

Alpha 1-adrenergic receptor stimulation with phenylephrine significantly decreased the maximum shortening velocity of skinned single ventricular myocytes from rats compared to control.

Why the study?

Does alpha 1-adrenergic receptor stimulation decrease maximum shortening velocity in skinned single ventricular myocytes from rats?

Population

Skinned single ventricular myocytes from rats

Comparison

Incubation with beta-receptor antagonist… vs Incubation with beta-receptor antagonist…

Design

Preclinical

Authors

KSKevin T. StrangUniversity of Wisconsin–Madison RMRichard L. MossUniversity of Vermont

Discussion

Member takes

Implication

Should not alter clinical practice; extends biochemical data on alpha-1 myofilament effects but leaves open human translation.

Key Points

To determine whether alpha-1 adrenergic receptor stimulation directly reduces the maximum shortening velocity of single skinned rat ventricular myocytes.
Isolated rat ventricular myocytes were pretreated with the beta-blocker propranolol in the presence or absence of the alpha-1 agonist phenylephrine, followed by rapid skinning to preserve myofilament phosphorylation.
Unloaded shortening velocity was measured using the slack-test method, and the relation between isometric tension, calcium concentration, and myosin heavy chain isoform composition was evaluated.
Unloaded shortening velocity was significantly lower in myocytes treated with the alpha-1 adrenergic agonist compared to control cells.
Alpha-1 adrenergic stimulation had no detectable effect on the calcium sensitivity of isometric tension.
Myosin heavy chain isoform composition accounted for a significant portion of the observed baseline variation in shortening velocity.

Structured PICO

Does alpha 1-adrenergic receptor stimulation decrease maximum shortening velocity in skinned single ventricular myocytes from rats?

Population

Skinned single ventricular myocytes from rats

Intervention

Incubation with beta-receptor antagonist propranolol in the presence of alpha 1-adrenergic receptor agonist phenylephrine

Comparator

Incubation with beta-receptor antagonist propranolol in the absence of phenylephrine (skinned control cells)

Outcome

Velocity of unloaded shortening (Vo)surrogate

Alpha 1-adrenergic receptor stimulation decreases maximum shortening velocity in rat ventricular myocytes, suggesting inhibition of cross-bridge cycling rate at the myofilament level.

Cite This Study

Strang et al. (1995) studied this question. alpha 1-adrenergic receptor agonist phenylephrine vs. control was evaluated on velocity of unloaded shortening (Vo). Alpha 1-adrenergic receptor stimulation with phenylephrine significantly decreased the maximum shortening velocity of skinned single ventricular myocytes from rats compared to control.

synapsesocial.com/papers/6a15378b79ff98d0de4e44be https://doi.org/10.1161/01.res.77.1.114

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α 1 -Adrenergic Receptor Stimulation Decreases Maximum Shortening Velocity of Skinned Single Ventricular Myocytes From Rats

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

α 1 -Adrenergic Receptor Stimulation Decreases Maximum Shortening Velocity of Skinned Single Ventricular Myocytes From Rats

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

Also Consider