Apart from its role in elevating red blood cell number, erythropoietin (Epo) exerts protective functions brain, retina and heart upon ischaemic injury. However, the physiological non-erythroid of Epo remain unclear. Here we use a transgenic mouse line (Tg21) constitutively overexpressing human brain to investigate Epo's impact on ventilation hypoxic exposure. Tg21 mice showed improved ventilatory response severe acute hypoxia moreover acclimatization chronic Furthermore, following bilateral...

Abstract Study Objectives We tested the hypothesis that estradiol (E2) protects against cardiorespiratory disorders and oxidative stress induced by chronic intermittent hypoxia (CIH) in adult female rats. Methods Sprague-Dawley rats (230–250 g) were ovariectomized implanted with osmotic pumps delivering vehicle or E2 (0.5 mg/kg/d). After 14 days of recovery, exposed to CIH (21%–10% O2: 8 h/d, 10 cycles per hour) room air (RA). 7 RA exposure, we measured arterial pressures (tail cuff),...

Ventilatory long-term facilitation (LTF; defined as gradual increase of minute ventilation following repeated hypoxic exposures) is well described in adult mammals and hypothesized to be a protective mechanism against apnea. In newborns, LTF absent during the first postnatal days, but its precise developmental pattern unknown. Accordingly, this study describes development. Additionally, we tested hypothesis that chronic intermittent hypoxia (CIH) from birth alters was estimated vivo using...

The effect of chronic hypoxia on gender differences in physiology and neurochemistry chemosensory pathways was studied prepubertal adult rats living at sea level (SL; Lyon, France) or high altitude (HA; La Paz, Bolivia, 3,600 m). HA had higher hematocrit (Ht%), Hb concentration, resting ventilatory rate (Ve 100 ), tyrosine hydroxylase (TH) activity carotid bodies (CB) than SL animals. At SL, females lower Ht% (46.0 ± 0.8 vs. 50.4 0.6% HA, P < 0.05 43.8 0.9 47.1 0.8% 0.05) (16.1 0.3 17.7...

While erythropoietin (Epo) and its receptor (EpoR) have been widely investigated in brain, the expression function of soluble Epo (sEpoR) remain unknown. Here we demonstrate that sEpoR, a negative regulator Epo's binding to EpoR, is present mouse brain down‐regulated by 62% after exposure normobaric chronic hypoxia (10% O 2 for 3 days). Furthermore, while normoxic minute ventilation increased 58% control mice following hypoxic acclimatization, sEpoR infusion during challenge efficiently...

We tested the hypothesis that ovarian steroids stimulate breathing through a dopaminergic mechanism in carotid bodies. In ovariectomized female rats raised at sea level, domperidone, peripheral D 2 -receptor antagonist, increased ventilation normoxia (minute = +55%) and acute hypoxia (+32%). This effect disappeared after 10 daily injections of (progesterone + estradiol). At high altitude (3,600 m, Bolivian Institute for High-Altitude Biology-IBBA, La Paz, Bolivia), neutered females had...

We tested the hypothesis that nuclear progesterone receptor (nPR) is involved in respiratory control and mediates stimulant effect of progesterone. Adult female mice carrying a mutation nPR gene (PRKO mice) wild-type controls (WT) were implanted with an osmotic pump delivering vehicle or (4 mg/kg/day). The instrumented EEG neck EMG electrodes connected to telemetry transmitter. animals placed whole body plethysmograph 7 days after surgery record ventilation, metabolic rate, EMGs for 4...

Phylogeographic studies showed that house mice ( Mus musculus ) originated in the Himalayan region, while common rats Rattus rattus and norvegicus come from lowlands of China India. Accordingly, it has been proposed its origins gave mice, but not rats, ability to invade ecological niches at high altitudes (pre-adaptation). This proposal is strongly supported by fact are distributed throughout world, practically absent above 2,500 m. Considering mammals colonize high-altitude environments...

Ecological studies show that mice can be found at high altitude (HA - up to 4000 m) while rats are absent these altitudes, and there no data explain this discrepancy. We used adult laboratory have been raised for more than 30 generations in La Paz, Bolivia (3600 m), compared their hematocrit levels, right ventricular hypertrophy (index of pulmonary hypertension) alveolar surface area the lungs. also whole-body plethysmography, indirect calorimetry pulse oxymetry measure ventilation,...

Abstract Aim We tested the hypothesis that estradiol (E 2 ) reduces aortic oxidative stress and endothelial dysfunction in ovariectomized ( OVX female rats exposed to room air RA or chronic intermittent hypoxia CIH ). Methods used intact treated with vehicle E (0.5 mg/kg/d) (21%‐10% O , 10 cycles/h, 8 h/d) for 7 35 days, measured arterial pressure, heart rate plasma endothelin‐1 levels. also thoracic samples, activities of pro‐oxidant enzymes NADPH NOX xanthine oxidase XO ), antioxidant...

Abstract Aim Chronic intermittent hypoxia (CIH) induces systemic (hypertension) and central alterations (mitochondrial dysfunction underlying cognitive deficits). We hypothesized that agonists of oestradiol receptors (ER) α β prevent CIH‐induced hypertension brain mitochondrial dysfunction. Methods Ovariectomized female rats were implanted with osmotic pumps delivering vehicle (Veh), the ERα agonist propylpyraoletriol (PPT — 30 μg/kg/day) or ERβ diarylpropionitril (DPN 100 μg/kg/day)....

We tested the hypothesis that membrane progesterone receptors (mPR) contribute to respiratory control in adult male and female mice. Mice were implanted with osmotic minipumps for continuous infusion of small interfering RNA (siRNA) directed against mPRα, mPRβ, or a solution fourth ventricle (to target brain stem areas) 14 days. then performed metabolic recordings by whole body plethysmography at rest response hypoxia (12% O2) hypercapnia (5% CO2, 5 min each). For each treatment, we have...

We tested the hypothesis that endogenous brain Epo is a respiratory stimulant. Adult (3 mo) and newborn (10 days) male female mice received an intracisternal (cisterna magna) injection of soluble receptor (sEpoR; competes with EpoR to bind Epo; 50 μg/ml) or vehicle (0.1% BSA in PBS). Twenty-four hours after injection, we used whole body plethysmography record minute ventilation (V̇e) tidal volume (V T ), frequency ( f R O 2 consumption (V̇o CO production (V̇co ) under normoxia progressive...

Human and animal studies on sleep-disordered breathing respiratory regulation show that the effects of sex hormones are heterogeneous. Because neonatal stress results in sex-specific disruption control adult rats, we postulate it might affect modulation induced by ovarian steroids female rats. The hypoxic ventilatory response (HVR) rats exposed to maternal separation (NMS) is ∼30% smaller than controls (24), but consequences NMS aging unknown. To address this issue, whole body...

New Findings What is the central question of this study? Does progesterone reduce effect chronic intermittent hypoxia (CIH) on arterial blood pressure, respiratory control and oxidative stress in nervous system ovariectomized rats? main finding its importance? Progesterone does not prevent elevation pressure rats exposed to CIH, but normalizes control, reduces cerebral stress. This study draws focus a potential role consequences sleep apnoea menopausal women. Abstract We tested hypothesis...

Sleep disordered breathing (SDB) is a complex, sex specific and highly heterogeneous group of respiratory disorders. Nevertheless, sleep fragmentation repeated fluctuations arterial blood gases for several hours per night are at the core problem; together, they impose significant stress to organism with deleterious consequences on physical mental health. SDB increases risk obesity, diabetes, depression anxiety disorders; however, same health issues factors SDB. So, which came first, chicken...

Abstract Introduction Interstitial lung disease encompasses a group of rare conditions causing inflammation and scarring tissue. The typical method monitoring activity is through pulmonary function tests performed in hospital setting. However, accessing care can be difficult for rural patients due to numerous barriers. This study assesses the feasibility acceptability home spirometry telemonitoring using MIR-Spirometers patientMpower home-monitoring platform with interstitial disease....

Perinatal stress disrupts normal development of the hypothalamo‐pituitary‐adrenal (HPA) axis. Adult male (but not female) rats previously subjected to a such as neonatal maternal separation (NMS) are characterized by chronic elevation plasma corticosterone (Cort) levels and an abnormally elevated hypoxic ventilatory response through mechanisms that remain unknown. The present study tested hypothesis increase Cort alone augments hypoxia in adult rats. Three groups Sprague–Dawley female were...

Adenosine triphosphate, acting through purinergic P2X receptors, has been shown to stimulate ventilation and increase carotid body chemoreceptor activity in adult rats. However, its role during postnatal development of the ventilatory response hypoxia is yet unknown. Using whole plethysmography, we measured normoxia moderate (12% fraction inspired O 2 , 20 min) before after intraperitoneal injection suramin (P2X 3 receptor antagonist, 40 mg/kg) 4-, 7-, 12-, 21-day-old Suramin reduced...