Restore hearing thanks to new drug

June 30, 2010

Researchers from the University of Auckland, New Zealand, have discovered that a potent new drug restores hearing after noise-induced hearing loss in rats. The landmark discovery found that injection of an agent called 'ADAC', activates adenosine receptors in cochlear tissues, resulting in recovery of hearing function. The finding paves the way for effective non-surgical therapies to restore hearing loss after noise-induced injury. Dr. Srdjan Vlajkovic and his team's work is published in a special edition of Springer's journal Purinergic Signalling, focusing on the inner ear.

Hearing loss from noise exposure is a leading occupational disease with up to five percent of the population at risk worldwide. It is particularly common in the military and in industrial settings (construction workers, mining, forestry and airline industry). At the present time, the only treatment strategies for hearing loss are and . Drug therapies for noise-induced hearing loss have only recently been proposed and, to date, there are virtually no treatments that can repair the damage to the and reduce the impact of hearing loss.

Vlajkovic and his team's study investigates the potential of adenosine amine congener (ADAC) - a selective A1 adenosine receptor agonist - in the treatment of noise-induced hearing loss. Wistar rats were exposed to narrow-band noise for 2 - 24 hours in an acoustic chamber to induce cochlear damage and permanent hearing loss. ADAC or placebo control was then administered by injection(s) in the abdomen, either as a single injection at six hours or multiple daily injections. The researchers measured the hearing in the rats before and after the treatments using a technique known as auditory brainstem response (ABR). They also used histological techniques to determine the number of missing cochlear after noise exposure and the noise-induced production of .

Their results show that cochlear injury and hearing loss in rats exposed to narrow-band noise can be substantially restored by ADAC administration after noise exposure. Early treatment starting six hours after noise exposure was the most effective and provided greater recovery than late treatment starting 24 hours after noise exposure. The most sustainable treatment strategy was the one involving multiple injections of ADAC for five days after . This therapy significantly attenuated noise-induced hearing loss and improved sensory hair cell survival.

The authors conclude: "This study underpins an important role of adenosine signaling in mitigation of cochlear injury caused by oxidative stress. ADAC in particular emerges as an attractive pharmacological agent for therapeutic interventions in noise-induced cochlear injury in instances of both acute and extended noise exposures."

Explore further: Rowdy hockey fans can cause hearing damage, say researchers

More information: Vlajkovic SM et al (2010). Adenosine amine congener mitigates noise-induced cochlear injury. Purinergic Signalling; 10.1007/s11302-010-9188-5

Related Stories

Rowdy hockey fans can cause hearing damage, say researchers

December 5, 2006

During last year's NHL playoffs, Edmonton Oilers' fans tried to earn the title of loudest arena in the game, but new University of Alberta research shows that even a few hours of exposure to that level of noise can be harmful.

Can you hear me now? Stem cells enhance hearing recovery

June 25, 2007

Tokyo, Japan -- Researchers have shown that bone marrow stem cells injected into a damaged inner ear can speed hearing recovery after partial hearing loss. The related report by Kamiya et al, “Mesenchymal stem cell transplantation ...

Fireworks can cause hearing loss in children

June 29, 2010

(PhysOrg.com) -- As the Fourth of July approaches, parents should remember that fireworks could cause permanent hearing loss in children, says a Purdue expert.

Recommended for you

Machine Translates Thoughts into Speech in Real Time

December 21, 2009

(PhysOrg.com) -- By implanting an electrode into the brain of a person with locked-in syndrome, scientists have demonstrated how to wirelessly transmit neural signals to a speech synthesizer. The "thought-to-speech" process ...

Quantum Theory May Explain Wishful Thinking

April 14, 2009

(PhysOrg.com) -- Humans don’t always make the most rational decisions. As studies have shown, even when logic and reasoning point in one direction, sometimes we chose the opposite route, motivated by personal bias or simply ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.