Platelet-activating factor receptor modulates respiratory adaptation to long-term intermittent hypoxia in mice.

Abstract

During hypoxia, release of platelet-activating factor (PAF) and activation of its cognate receptor (PAFR) regulate neural transmission and are required for full expression of peak hypoxic ventilatory response (pHVR) but not hypercapnic ventilatory response. However, it is unclear whether PAFR underlie components of long-term ventilatory adaptations to hypoxia. To examine this issue, adult male PAFR(+/+) and PAFR(-/-) mice were exposed to intermittent hypoxia (IH) consisting of 90 s 21% O(2) and 90 s 10% O(2) for 30 days, and normoxic and hypoxic ventilatory patterns were assessed using whole body plethysmography. Starting at day 14 of IH, normoxic ventilation in PAFR(-/-) was reduced significantly compared with PAFR(+/+) mice (P < 0.001), the latter exhibiting a prominent long-term ventilatory facilitation (LTVF). However, IH-exposed PAFR(-/-) mice had markedly enhanced pHVR and hypoxic ventilatory decline that became similar to those of IH-exposed PAFR(+/+) mice. Thus we postulate that PAFR expression and/or function underlies critical components of IH-induced LTVF but does not play a role in the potentiation of the hypoxic ventilatory response after IH exposures.

• Authors: Stephen R Reeves, David Gozal
• Journal: American journal of physiology. Regulatory, integrative and comparative physiology (Am J Physiol Regul Integr Comp Physiol) Vol. 287 Issue 2 Pg. R369-74 (Aug 2004) ISSN: 0363-6119 [Print] United States
• PMID: 15087283 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Platelet Activating Factor
• Platelet Membrane Glycoproteins
• Receptors, G-Protein-Coupled
• platelet activating factor receptor

Topics

• Adaptation, Physiological (physiology)
• Animals
• Chronic Disease
• Female
• Hypoxia (metabolism, physiopathology)
• Male
• Mice
• Mice, Inbred C57BL
• Mice, Mutant Strains
• Platelet Activating Factor (metabolism)
• Platelet Membrane Glycoproteins (genetics, metabolism)
• Plethysmography, Whole Body
• Receptors, G-Protein-Coupled (genetics, metabolism)