Permanent URL to this publication: http://dx.doi.org/10.5167/uzh-14428
Soliz, J; Soulage, C; Hermann, D M; Gassmann, M (2007). Acute and chronic exposure to hypoxia alters ventilatory pattern but not minute ventilation of mice overexpressing erythropoietin. American Journal of Physiology. Regulatory, Integrative and Comparative Physiology, 293(4):R1702-R1710.
Apart from enhancing red blood cell production, erythropoietin (Epo) has been shown to modulate the ventilatory response to reduced oxygen supply. Both functions are crucial for the organism to cope with increased oxygen demand. In the present work, we analyzed the impact of Epo and the resulting excessive erythrocytosis in the neural control of normoxic and hypoxic ventilation. To this end, we used our transgenic mouse line (Tg6) that shows high levels of human Epo in brain and plasma, the latter leading to a hematocrit of approximately 80%. Interestingly, while normoxic and hypoxic ventilation in Tg6 mice was similar to WT mice, Tg6 mice showed an increased respiratory frequency but a decreased tidal volume. Knowing that Epo modulates catecholaminergic activity, the altered catecholaminergic metabolism measured in brain stem suggested that the increased respiratory frequency in Tg6 mice was related to the overexpression of Epo in brain. In the periphery, higher response to hyperoxia (Dejours test), as well as reduced tyrosine hydroxylase activity in carotid bodies, revealed a higher chemosensitivity to oxygen in transgenic mice. Moreover, in line with the decreased activity of the rate-limiting enzyme for dopamine synthesis, the intraperitoneal injection of a highly specific peripheral ventilatory stimulant, domperidone, did not stimulate hypoxic ventilatory response in Tg6 mice. These results suggest that high Epo plasma levels modulate the carotid body's chemotransduction. All together, these findings are relevant for understanding the cross-talk between the ventilatory and erythropoietic systems exposed to hypoxia.
|Item Type:||Journal Article, refereed, original work|
|Communities & Collections:||05 Vetsuisse Faculty > Institute of Veterinary Physiology|
04 Faculty of Medicine > Center for Integrative Human Physiology
04 Faculty of Medicine > University Hospital Zurich > Clinic for Neurology
|DDC:||570 Life sciences; biology|
610 Medicine & health
|Deposited On:||20 Mar 2009 11:30|
|Last Modified:||23 Nov 2012 16:26|
|Publisher:||American Physiological Society|
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