If the rats used in a recent experiment by School of Medicine pharmacology professor Dr. Sven-Eric Jordt invaded Samurai, they would have an easier time gorging themselves on spicy sushi rolls than the restaurant’s regular patrons would.
“They could eat as much wasabi as they wanted, they don’t mind at all,” said Dr. Diana Bautista, a member of the University of California, San Francisco laboratory research team who worked alongside Jordt.
In his most recent experiment, Jordt, a new addition to the Medical School’s Department of Pharmacology, was able to isolate the specific pain receptor sensitive to the spicy ingredient in wasabi and mustard, commonly referred to as mustard oil. By cloning rats without the gene responsible for activating the sensation of spiciness-induced heat, Jordt and his team intend to use the results to help create more effective pain medication.
The pain receptor in question, TRPA1, responds to various environmental irritants in plants, including mustard oil.
“We have been very interested in researching natural products that induce pain, things that are pungent that have evolved to ward off things that would eat [the plants],” Bautista said.
Jordt said he then focused on mustard oil in particular because it had been used in pain research for many decades, but its actual targets were not known. Before Jordt’s experiment, the effects of this irritant had been tested on individual cells, but never in a living animal.
The researchers’ remarkable rats may aid in the production of a new wave of prescription pain medication. By studying TRPA1’s responses to structurally similar chemicals, Jordt said they may discover it to be the receptor integral in the pain involved with arthritis. Research project member Andrew Read ’05 said a new prescription drug could be developed to take the place of Vioxx and Bextra, which were found to cause severe heart problems and were banned from U.S. markets in September 2004.
Dr. David Julius, another member of the research team employed by UCSF, said TRPA1 may also be an actor in air-constriction disorders, such as asthma. And Bautista said TRPA1 is likely the cause of a severe side effect of some forms of chemotherapy — namely, bladder inflammation that causes bleeding.
Bautista said people sensitive to the procedure bleed due to bladder inflammation, and have to put a halt to the chemotherapy, making a TRPA1 inhibiting medication a future goal. Julius expects medications specifically targeting TRPA1-induced pain to be developed in approximately five to 10 years.
The results of the research are also applicable to pains a college student would more likely have. Once an injury is sustained, such as an athletic injury, a person may become hypersensitive to pain in that area, Bautista said. Blocking TRPA1 would also block this process, enabling an athlete to recuperate much faster.
Read said the team would continue to explore further possibilities, provided they have the resources.