Aims: 

Hypoxia is a state of reduced oxygen supply to the tissue below physiological levels despite adequate perfusion of the tissue by blood. The purpose of the study was to test, whether hypoxia can affect levels of individual IP3 receptors in neuronal and cardiac cells.3

Methods: 

We compared mRNA levels of Type 1 and 2 IP3 receptors by reverse transcription and polymerase chain reaction (RT-PCR) and also protein levels by Western blot and immunofluorescence. Five mice were subjected to hypoxia and compared to 5 control mice. Moreover, hypoxia was tested on primary culture of cerebellar granular cells and also on H962 cardiomyocyte culture.

Results: 

We observed significant increase in both, type 1 and 2 IP3 receptors in all tested cells on mRNA and protein level after 24 hours exposure to 4% hypoxia. Nevertheless, while maximal increase in type 1 IP3R occurs after 24 hours, type 2 IP3R mRNA was maximally increased after 3 hours.

Conclusion: 

We have shown that hypoxia significantly increases types 1 and 2 IP3 receptors in neuronal and cardiac cells. Physiological relevance of this observation remains to be elucidated; nevertheless, involvement of IP3Rs in remodelling of at least neuronal cells is probable.

This work was supported by grants VEGA 2/6078, 2/7123 and APVV 51027404.