Right Ventricular Hypertrophy in Guinea Pigs Exposed to Simulated High Altitude

Valdivia, Enrique

doi:10.1161/01.res.5.6.612

Cited by 35 publications

(5 citation statements)

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“…C). The hypertrophic response of the right ventricle to hypoxia is ubiquitous among mammals adapted to low altitude (Valdiva ; Nakanishi et al. ; Sharma et al.…”

Section: Discussionmentioning

confidence: 99%

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Maladaptive phenotypic plasticity in cardiac muscle growth is suppressed in high‐altitude deer mice

et al. 2018

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How often phenotypic plasticity acts to promote or inhibit adaptive evolution is an ongoing debate among biologists. Recent work suggests that adaptive phenotypic plasticity promotes evolutionary divergence, though several studies have also suggested that maladaptive plasticity can potentiate adaptation. The role of phenotypic plasticity, adaptive, or maladaptive, in evolutionary divergence remains controversial. We examined the role of plasticity in evolutionary divergence between two species of Peromyscus mice that differ in native elevations. We used cardiac mass as a model phenotype, since ancestral hypoxia-induced responses of the heart may be both adaptive and maladaptive at high-altitude. While left ventricle growth should enhance oxygen delivery to tissues, hypertrophy of the right ventricle can lead to heart failure and death. We compared left-and right-ventricle plasticity in response to hypoxia between captive-bred P. leucopus (representing the ancestral lowland condition) and P. maniculatus from high-altitude. We found that maladaptive ancestral plasticity in right ventricle hypertrophy is reduced in high-altitude deer mice. Analysis of the heart transcriptome suggests that changes in expression of inflammatory signaling genes, particularly interferonregulatory factors, contribute to the suppression of right ventricle hypertrophy. We found weak evidence that adaptive plasticity of left ventricle mass contributes to evolution. Our results suggest that selection to suppress ancestral maladaptive plasticity plays a role in adaptation.

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“…C). The hypertrophic response of the right ventricle to hypoxia is ubiquitous among mammals adapted to low altitude (Valdiva ; Nakanishi et al. ; Sharma et al.…”

Section: Discussionmentioning

confidence: 99%

“…; Reddy and Bernstein ). Excessive erythropoiesis, pulmonary remodeling, and subsequent right‐ventricle hypertrophy are ubiquitous responses to high‐altitude hypoxia in mammals adapted to low altitude (Valdivia ; Nakanishi et al. ; Sharma et al.…”

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confidence: 99%

Maladaptive phenotypic plasticity in cardiac muscle growth is suppressed in high‐altitude deer mice

et al. 2018

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“…Cardiac hypertrophy in altitude-adapted rats has been observed (TIMIRAS et al, 1957;VALDIVIA, 1957). Generally, hypoxia increases the work output of the heart by elevating heart rate, blood viscosity, and blood volume, subsequently a work hypertophy develops.…”

Section: Discussionmentioning

confidence: 99%

Enzymatic responses and adaptations to swimming training and hypobaric hypoxia in postnatal rats.

1985

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Twenty four male Sprague-Dawley rats, 35 days old, were randomly assigned to one of four groups : 2 resting control groups and 2 swimming groups. The sea level-control and the sea level-swimming groups were housed 5 weeks at 1,011 hPa (760 mmHg) while the hypoxic control and swimming groups were housed for 1 week at 678 hPa, followed by 4 weeks at 611 hPa. The swimming rats were subjected to a swimming program of 30 min, 6 days/week for 5 weeks. Both hypoxia groups developed significantly higher Hb and Hct levels than the sea level groups. The glycogen content in the extensor digitorum longus (EDL) and the deep portion of the vastus lateralis (DVL) muscles of the sea levelswimming group were significantly greater as compared to the hypoxia swimming group. The succinate dehydrogenase (SDH) activity in the sea level-control group was significantly lower in the EDL muscle than in the 3 other groups, and in the DVL muscle lower than that of the sea levelswimming group. Histochemically, hypoxia and swimming training induced significant increases in the fast-twitch-oxidative-glycolytic (FOG) fibers (6-11 %) in soleus muscle, and decreases in the slow-twitch-oxidative (SO) fibers. The EDL muscles had significantly higher percentages of FOG fibers in the hypoxia and swimming groups than in the sea level control group. On the basis of the present study it seems probable that hypoxia is a triggering factor for the conversions of muscle fiber types and the increase in oxidative capacity.

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“…Permanent altitude hypoxia [Valdivia, 1957;H ultgren et al, 1963] as well as intermittent altitude hypoxia [Dean et al, 1968;A ltland and H ighman. 1971;M cG rath et al, 1973] induce in experimental animals right ventricular hypertrophy.…”

Section: Right Ventricular Hypertrophymentioning

confidence: 99%

Reversibility of Pulmonary Hypertension and Right Ventricular Hypertrophy Induced by Intermittent High Altitude Hypoxia in Rats

Ressl¹,

Urbanová²,

Widimský³

et al. 1974

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The effect of intermittent altitude hy- poxia simulated in a hypobaric chamber (7,000 m, 8 h daily, 5 days a week) on the lesser circulation and heart weight was studied in rats. A marked chronic pulmonary hypertension and hypertrophy of the right ventricle after 24 exposures was found. No further rsignificant increase after 60 exposures was reached. Signs of right heart failure were found both after 24 and 60 exposures. 70 days after the removal of the rats from the hypobaric chamber and recovery in normoxic conditions, the right ventricular systolic pressure and right ventricular weight did not differ from controls showing reversibility of pulmonary hypertension and right ventricular hypertrophy even in animals with signs of right heart failure.

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Right Ventricular Hypertrophy in Guinea Pigs Exposed to Simulated High Altitude

Abstract: Guinea pigs exposed to simulated altitudes of 18,000 feet developed right heart dilatation followed by hypertrophy, more conspicuous in the infundibular area of the right ventricle. Under the described experimental conditions, pulmonary artery hypertension may be the etiologic factor.

Cited by 35 publications

References 8 publications

Maladaptive phenotypic plasticity in cardiac muscle growth is suppressed in high‐altitude deer mice

Maladaptive phenotypic plasticity in cardiac muscle growth is suppressed in high‐altitude deer mice

Enzymatic responses and adaptations to swimming training and hypobaric hypoxia in postnatal rats.

Reversibility of Pulmonary Hypertension and Right Ventricular Hypertrophy Induced by Intermittent High Altitude Hypoxia in Rats

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