can you respray high gloss cupboards?

A professional spraying outfit should certainly be able to do this job - although I doubt it will be cost-effective compared with buying new doors from one of the specialist companies.
The high gloss finish would need to be carefully prepared to ensure a good key for the new paint to stick to.
Spraying is not a job to be undertaken lightly as an amateur - it is a skilled job, with tools which seem temperamental to inexperienced users. Also the paints used are relatively toxic, and you need somewhere enclosed with high powered extraction and filtration.
In case you are looking to repair a small area, again, I would suggest that this will not be practical on a DIY level - it is very tricky to match colours and finish.

Dil Green
September 2010