Cardiovascular changes during acute episodic repetitive hypoxic and hypercapnic breathing in rats

Bakehe, M.; Miramand, J.L.; Chambille, B; Gaultier, C; Escourrou, P.

doi:10.1183/09031936.95.08101675

Cited by 12 publications

(9 citation statements)

References 20 publications

(32 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Moreover, this short cycle duration limited the hypoxia-induced hyperventilation that may induce hypocapnia and cardiovascular changes. We selected a 4% FI O 2 nadir based on our experience and previous studies showing that FI O 2 of less than 5% produced maximal changes in BP and HR (14). We did not record sleep to show sleep disruption, which may have affected our results.…”

Section: Methodologic Considerationsmentioning

confidence: 99%

“…Some of the results of this study have been previously reported in the form of an abstract (13). Days 1,14,and 35), with respective normoxic control animals (NX group) exposed to air in identical chambers (n 5 8-16 per group). Procedure-related effects were assessed using a second control group of unhandled mice (UN group).…”

Section: What This Study Adds To the Fieldmentioning

confidence: 99%

See 1 more Smart Citation

Intermittent Hypoxia Induces Early Functional Cardiovascular Remodeling in Mice

Demattéis¹,

Julien²,

Guillermet³

et al. 2008

Am J Respir Crit Care Med

146

129

View full text Add to dashboard Cite

Intermittent hypoxia induces sequential cardiovascular events suggesting increased chemoreflex and depressed baroreflex, resulting in sympathoadrenal hyperactivity, early hemodynamic alterations with proximal histologic remodeling, and delayed changes in peripheral vasoreactivity. Such early alterations before overt cardiovascular disease strengthen the need for identifying at-risk individuals for systematic treatment.

show abstract

Section: Methodologic Considerationsmentioning

confidence: 99%

Section: What This Study Adds To the Fieldmentioning

confidence: 99%

Intermittent Hypoxia Induces Early Functional Cardiovascular Remodeling in Mice

Demattéis¹,

Julien²,

Guillermet³

et al. 2008

Am J Respir Crit Care Med

146

129

View full text Add to dashboard Cite

show abstract

“…Recent evidence in animals [9][10][11] has demonstrated that repetitive hypoxic stimuli, simulating the chemical changes produced by apnoeas lead to systemic hypertension either during the exposure or during the recovery period. A more direct approach to the pulmonary vascular effects of repetitive hypoxaemia has been used by IWASE et al [12].…”

Section: Aamentioning

confidence: 99%

Time course of pulmonary artery pressure during sleep in sleep apnoea syndrome: role of recurrent apnoeas

Sforza

Laks²,

Grunstein³

et al. 1998

Eur Respir J

View full text Add to dashboard Cite

The increase in pulmonary arterial pressure (Ppa) during acute hypoxia is mainly related to alveolar hypoxaemia inducing vasoconstriction of precapillary pulmonary arterioles [1,2] whereas during chronic hypoxia, mechanical and hormonal factors make the vessels adapt to hypoxia and modify their response to chemical stimulus [3]. Furthermore, the temporal profile of the hypoxaemic stimulus may have a substantial effect on the pulmonary vascular response [4] as suggested by experimental studies allowing that repeated exposure to intermittent hypoxaemia [5] enhances the pulmonary hypoxic pressor response.Previous studies [6] in obstructive sleep apnoea (OSAS) patients have shown that repeated desaturations from obstructive apnoeas induce a transient increase in Ppa that, together with daytime hypoxaemia, is considered to be the key factor responsible for daytime pulmonary hypertension [7,8]. Recent evidence in animals [9][10][11] has demonstrated that repetitive hypoxic stimuli, simulating the chemical changes produced by apnoeas lead to systemic hypertension either during the exposure or during the recovery period. A more direct approach to the pulmonary vascular effects of repetitive hypoxaemia has been used by IWASE et al. [12]. Using a canine model they have demonstrated a progressive increase in systemic and pulmonary arterial pressure during repetitive hypoxaemic exposure. On the basis of these latter findings a trend in the pulmonary arterial pressure response to repetitive hypoxaemia similar to the one produced experimentally may occur in patients with OSAS.The two aims of the present study were: 1) to ascertain whether recurrent apnoea-related oxygen desaturations are associated with a progressive rise in Ppa during the night in OSAS patients; 2) if there was a rise in the expected direction, to determine whether diurnal and nocturnal variables would predict the degree of progressive nocturnal increase in Ppa. Patients and methods PatientsThirty five consecutive patients referred to the sleep laboratory for habitual snoring and possible sleep apnoea We have, therefore, examined the nocturnal trend of Ppa in seven obstructive sleep apnoea syndrome (OSAS) patients and in five snorers. Mean Ppa was measured before, at the start, at the end and after the selected apnoeas. The analysis was performed for each 1 h period for at least 7 h throughout the night on at least 10 randomly selected apnoeas per hour. In snorers, 100 randomly chosen values were measured during every hour of the night. In the morning after the nocturnal study, the Ppa responses to acute hypoxia and hypercapnia were measured.No Ppa changes throughout the 7 h were found during sleep in snorers (Ppa slope:-0.002±0.10 mmHg·h -1 ). In OSAS patients a small but significant increase in Ppa throughout the night was noted, affecting the values before (Ppa slope: 0.7±0.16 mm Hg·h -1 ), at the start of apnoea (Ppa slope: 0.53±0.1 mmHg·h -1 ) as well as at the end (Ppa slope: 0.44±0.08 mmHg·h -1 ) and in the postapnoeic period (Ppa slope: 0.55±0.1 mmHg...

show abstract

“…The method used to promote asphyxia in this study was based on a previous study using a plastic bag to obtain this experimental condition 28 and it seemed reliable because it reproduces bradycardia as reported in literature 29 which induces an initial increase in waking 30 . The recovery of neonatal rats after 60 minutes of asphyxia cannot be attributed to methodological inadequacy because their high resistance is well documented 31 .…”

Section: Discussionmentioning

confidence: 99%

Compensatory rebound of body movements during sleep, after asphyxia in neonatal rats

Suarez

Hoshino

2008

Acta Cir. Bras.

View full text Add to dashboard Cite

Purpose:The usefulness of body movements that occur during sleep when assessing perinatal asphyxia and predicting its longterm consequences is contradictory. This study investigated whether neonatal rats manifest these movements in compensatory rebound after asphyxia, and if these alterations play an important role in its pathogenesis. Methods: Eight neonatal rats (aged 6-48h) were implanted with small EMG and EKG electrodes and sleep movements were recorded over a 30-minute control period. Recordings were continued during asphyxia caused by the enclosure of the animal in a polyvinyl sheet for 60 minutes, followed by a 30-minute recovery period. Results: Heart rate was lowered to bradycardic level during asphyxia causing behavioral agitation and increased waking time during the initial phase (30 minutes). Sleep-related movements were also significantly reduced from 12.5 ± 0.5 (median ± SE/2min) to 9.0 ± 0.44 in the final half of the period (Anova, p<0.05). Movement frequency increased in the recovery period to 15.0 ± 0.49 (Anova, p<0.05). Conclusion: These data show that newborn rats present compensatory rebound of body movements during sleep which may help in the diagnosis of asphyxia and other problems related to sleep parameters. Key words: Sleep. Infant, Newborn. Asphyxia. Motor Activity. Rats. RESUMO Objetivo:A utilidade dos movimentos corporais (MC) que ocorrem durante o sono para diagnosticar e predizer as conseqüências, em longo prazo, da asfixia perinatal é contraditório. Este estudo investigou se ratos recém-nascidos (RN) manifestam MC em resposta compensatória à asfixia, e se estas alterações podem ter alguma importância na sua patogênese. Métodos: Oito ratos RN (6-48h de vida) foram submetidos à implantação de pequenos eletrodos para registros da eletromiografia e eletrocardiografia. Os MC e a freqüência cardíaca (FC) foram registrados durante períodos de 30 min: fase controle (F 1 ), fases de asfixia (F 2 ; F 3 ) e fase de recuperação pós-asfixia (F 4 ). A asfixia foi promovida pelo envolvimento completo do animal com uma lâmina de polivinil. Resultados: A FC diminuiu progressivamente durante F 2 e F 3 até a bradicardia. Em F 2 houve grande agitação dos animais e aumento dos períodos de vigília. Em F 3 houve redução significante dos MC de 12,5 ± 0,5 (Md ± SE/2min) para 9,0 ± 0,44 (P<0,05). A freqüência dos MC aumentou em F 4 para 15,0 ± 0,49. Conclusão: Estes dados mostram que ratos RN com asfixia apresentam MC compensatórios durante o sono que podem ajudar no diagnóstico desta afecção e de outros problemas relacionados aos parâmetros do sono. Descritores: Sono. Recém-Nascido. Asfixia. Atividade Motora. Ratos.

show abstract

Cardiovascular changes during acute episodic repetitive hypoxic and hypercapnic breathing in rats

Cited by 12 publications

References 20 publications

Intermittent Hypoxia Induces Early Functional Cardiovascular Remodeling in Mice

Intermittent Hypoxia Induces Early Functional Cardiovascular Remodeling in Mice

Time course of pulmonary artery pressure during sleep in sleep apnoea syndrome: role of recurrent apnoeas

Compensatory rebound of body movements during sleep, after asphyxia in neonatal rats

Contact Info

Product

Resources

About