Patients suffering from digestive disorders such as irritable bowel syndrome, chronic constipation and gastroesophageal reflux disease often exhibit abnormal gastrointestinal (GI) muscle contractions. Understanding how such muscle movement is regulated is thus an important goal of current research. To that end, Qun-Yong Zhou of the University of California at Irvine and his colleagues first focused on proteins from snake venom and frog skin secretions that stimulate GI smooth muscle contractions in guinea pigs. They then set about searching for human versions of these proteins, combing through chemical databases and testing candidates on guinea pig intestinal muscles. Their efforts were rewarded: the team found two human proteins expressed in the GI tract that are chemically similar to those from the frog and snake and have potent and specific effects on GI smooth muscle.
"These proteins appear to control intestinal muscles and could be used to form treatments for diseases caused by abnormal contractions of the gut," Zhou reports. He further notes that such treatments could help reduce vomiting and other GI side effects of cancer chemotherapy. Actual remedies are a long way off, however. "We still need to map out exactly how these proteins work," Zhou remarks, "and see if they work the same way in humans before we begin to develop treatments for intestinal disorders."