U.S. researchers suggest it may be possible to grow new arteries in coronary patients. Researchers at the Yale School of Medicine in New Haven, Conn., say this new non-invasive method -- a biological bypass -- could unblock clogged arteries without surgery. "Successfully growing new arteries could provide a biological option for patients facing bypass surgery," study leader Dr. Michael Simons of the Yale School of Medicine says in a statement quoted by the United Press International (UPI). Simons and colleagues studied mice and zebra fish and found the key to growing arteries was not encouraging growth but stopping two signaling pathways that worked to inhibit growth. "We found that there is a cross-talk between the two signaling pathways. One half of the signaling pathway inhibits the other. When we inhibit this mechanism, we are able to grow arteries," Simons says in a statement. "Instead of using growth factors, we stopped the inhibitor mechanism by using a drug that targets a particular enzyme called P13-kinase inhibitor." The study, published in Journal of Clinical Investigation, says the finding opens the possibility of developing a new class of medications to grow new arteries. "The next step is to test this finding in a human clinical trial," Simons says.