Can Apigee Edge proxy to a backend service that is running on my local server?

[#1]

I am trying to create a pass through service with apigee. I am able to call a default backend service (ex:

http://api.search.live.net/json.aspx?query=sushi&sources=web) and getting a response back. But when I try to call a backend service(tibco service using http://127.0.0.1:50140/test) which running on my local machine, I am getting connection refused error ("The Service is temporarily unavailable"). But I can see my backend service is running fine and I am able to hit my backend service from browser but not through apigee.

Is there any other configuration that i need to do to hit my backend service(say i need to register my backend Url somewhere in apigee)? Can someone please help?