I'm in software so not the same field, although there are similarities. In my experience, companies that state in job requirements that you must have a degree are looking to get the best candidates, as they may have gotten burned hiring people without degrees who weren't up to the task.
However it's also been my experience that if you know your stuff and don't have a degree, and blow them out of the water with your knowledge in a technical interview, and can actually back that up with solid work once you're in (hence, you know your stuff), companies will make an exception to this rule for the top "self-taught" candidates.
The bottom line is if you don't have a degree in Computer Science (or any degree) and work in IT, you must really know your stuff and be damn good at your particular skillset, adapt quickly, learn new or unfamiliar technologies quickly and master them, and you'll do just fine with all but the most anal-retentive must-have-degree-at-all-costs type of employers. One that comes to mind would be a University
Of course it helps to have experience as well. But the catch 22 is, well how to I gain experience if no one will hire me with no experience? Get a foot in the door at a lower grade position and increase responsibilities there, and as long as your skillset increases and expands constantly, you will always have opportunities in this industry, whether its software or systems admin or DBA, doesn't matter.
That's been my experience anyway.