one of my mentors commented on the link between the urea cycle and gluconeogenesis: in the lower left portion of the image you'll see a fumarate 'exiting' the urea cycle. It enters the TCA cycle and is funneled from there to glucose via gluconeogenesis. Given fumarate's entry point into the TCA cycle, it also produces NADH which is needed to convert 1,3-BPG into 3-GP in gluconeogenesis.

... and they're not really these clean "cycles" in vivo ...