What question did this study set out to answer?

To investigate whether developmental differences in myocardial tolerance to respiratory and metabolic acidosis are driven by alterations in intracellular pH regulation or intracellular calcium dynamics.

July 1, 1990Circulation ResearchOpen Access

Effect of acidosis on intracellular pH and calcium concentration in the newborn and adult rabbit myocardium.

View Full Paper

Ask AI

Bookmark

Population

Isolated heart and isolated myocyte preparations from newborn (5-7 days old) and adult rabbits.

Comparison

Respiratory or metabolic acidosis vs Adult rabbit myocardium and baseline conditions

Design

Preclinical

Authors

TNToshio NakanishiTokyo Women's Medical University MSM. SeguchiSeirei Hamamatsu General Hospital TTT. TsuchiyaKai Research (United States)

Discussion

Member takes

Implication

Suggests caution extrapolating adult acidosis responses to neonates; leaves open human translation from rabbit models.

Key Points

To investigate whether developmental differences in myocardial tolerance to respiratory and metabolic acidosis are driven by alterations in intracellular pH regulation or intracellular calcium dynamics.
Isolated whole heart and single myocyte preparations from newborn (5–7 days old) and adult rabbits were loaded with fluorescent indicators BCECF for pH and fura-2 for calcium.
Monitored left ventricular pressure, single-cell contraction, and fluorescence emission ratios at specific excitation wavelengths during respiratory and metabolic acidosis.
Depression of myocardial contractile function during respiratory and metabolic acidosis was less pronounced in newborns than in adults.
Intracellular pH decreased in both groups during acidosis, but the magnitude of the decrease was significantly less in newborns compared to adults.
Diastolic and systolic intracellular calcium levels increased during respiratory acidosis, with similar net changes observed between newborn and adult groups.

Structured PICO

Population

Isolated heart and isolated myocyte preparations from newborn (5-7 days old) and adult rabbits.

Intervention

Respiratory or metabolic acidosis

Comparator

Adult rabbit myocardium (for age comparison) and baseline conditions

Outcome

Intracellular pH (pHi), intracellular calcium concentration ([Ca]i), and contractile function (left ventricular pressure and cell contraction magnitude)surrogate

Newborn rabbit myocardium shows greater resistance to acidosis-induced contractile depression than adult myocardium, driven by smaller changes in intracellular pH rather than differences in calcium handling.

Cite This Study

Nakanishi et al. (1990) studied this question.

synapsesocial.com/papers/6a9043586bfd95d7bd4dd514 https://doi.org/10.1161/01.res.67.1.111

View Full Paper

Ask AI

Bookmark

Effect of acidosis on intracellular pH and calcium concentration in the newborn and adult rabbit myocardium.

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Effect of acidosis on intracellular pH and calcium concentration in the newborn and adult rabbit myocardium.

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

Also Consider