title: Chronic overexpression of cerebral Epo improves the ventilatory response to acute hypoxia during the postnatal development.
abstract: Clinicians observed that the treatment of premature human newborns for anemia with erythropoietin (Epo) also improved their respiratory autonomy. This observation is in line with our previous in vitro studies showing that acute and chronic Epo stimulation enhances fictive breathing of brainstem-spinal cord preparations of postnatal day 3-4 mice during hypoxia. Furthermore, we recently reported that the antagonization of the cerebral Epo (by using the soluble Epo receptor; sEpoR) significantly reduced the basal ventilation and the hypoxic ventilatory response of 10 days old mice. In this study, we used transgenic (Tg21) mice to investigate the effect of the chronic cerebral Epo overexpression on the modulation of the normoxic and hypoxic ventilatory drive during the post-natal development. Ventilation was evaluated by whole body plethysmography at postnatal ages 3 (P3), 7 (P7), 15 (P15) and 21 (P21). In addition Epo quantification was performed by RIA and mRNA EpoR was evaluated by qRT-PCR. Our results showed that compared to control animals the chronic Epo overexpression stimulates the hypoxic (but not the normoxic) ventilation assessed as VE/VO2 at the ages of P3 and P21. More interestingly, we observed that at P7 and P15 the chronic Epo stimulation of ventilation was attenuated by the down regulation of the Epo receptor in brainstem areas. We conclude that Epo, by stimulating ventilation in brainstem areas crucially helps tolerating physiological (e.g., high altitude) and/or pathological (e.g., respiratory disorders, prematurity, etc.) oxygen deprivation at postnatal ages.
authors.affiliation: Department of Pediatrics, Laval University Center de Recherche du Center Hospitalier Universitaire (CHU) de Québec, Hôpital St-François d'Assise, 10 Rue de l'Espinay, Québec, QC G1L 3L5, Canada. Electronic address: celine.caravagna.1@ulaval.ca.
authors.forename: Céline
authors.initials: C
authors.lastname: Caravagna
authors.affiliation: Institute of Veterinary Physiology, Vetsuisse-Faculty University of Zurich, Winterthurerstrasse 260, CH-8057 Zurich, Switzerland. Electronic address: edith.schneidergasser@uzh.ch.
authors.forename: Edith M
authors.initials: EM
authors.lastname: Schneider Gasser
authors.affiliation: Department of Pediatrics, Laval University Center de Recherche du Center Hospitalier Universitaire (CHU) de Québec, Hôpital St-François d'Assise, 10 Rue de l'Espinay, Québec, QC G1L 3L5, Canada. Electronic address: orlane.ballot.1@ulaval.ca.
authors.forename: Orlane
authors.initials: O
authors.lastname: Ballot
authors.affiliation: Department of Pediatrics, Laval University Center de Recherche du Center Hospitalier Universitaire (CHU) de Québec, Hôpital St-François d'Assise, 10 Rue de l'Espinay, Québec, QC G1L 3L5, Canada. Electronic address: joseph.vincent@crsfa.ulaval.ca.
authors.forename: Vincent
authors.initials: V
authors.lastname: Joseph
authors.affiliation: Department of Pediatrics, Laval University Center de Recherche du Center Hospitalier Universitaire (CHU) de Québec, Hôpital St-François d'Assise, 10 Rue de l'Espinay, Québec, QC G1L 3L5, Canada. Electronic address: Jorge.soliz@crchuq.ulaval.ca.
authors.forename: Jorge
authors.initials: J
authors.lastname: Soliz
mesh_terms: D000367:Age Factors; D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D002540:Cerebral Cortex / Q000254:growth & development* / Q000378:metabolism*; D004921:Erythropoietin / Q000235:genetics* / Q000378:metabolism*; D005260:Female; D015870:Gene Expression; D000860:Hypoxia / Q000473:pathology* / Q000503:physiopathology; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D010991:Plethysmography; D011863:Radioimmunoassay; D017467:Receptors, Erythropoietin / Q000235:genetics / Q000378:metabolism; D012737:Sex Factors; D013997:Time Factors
chemical_list: D017467:Receptors, Erythropoietin; D004921:Erythropoietin
keywords: Brainstem; Hypoxia; Post-natal development; Respiration