Medicine Gastroenterology News Archive Featured in the Media JeffNEWS

Gastroenterology researcher Satish Rattan, DVM, professor of medicine at Jefferson Medical College of Thomas Jefferson University in Philadelphia, has been awarded $1.6 million from the National Institutes of Health to study the molecular mechanisms involved in maintaining smooth muscle tone of the internal anal sphincter (IAS), which is crucial for normal bowel functioning.

In research over the past 20 years, Dr. Rattan, who is in the Division of Gastroenterology and Hepatology in the Department of Medicine, has found that IAS basal tone owes much to the distinct characteristics of smooth muscle in this region. He and his co-workers also found that nitric oxide is the major neurotransmitter for IAS relaxation, which again is critical for a normal bowel. The work has had implications for therapies for a variety of gastrointestinal disorders.

When the IAS tone is too high – or “hypertensive” – the result can be constipation, anal fissures and hemorrhoids. The IAS is important for continence and is controlled autonomically (as is all smooth muscle), as opposed to the external sphincter, which as skeletal muscle is voluntary. In contrast to the hypertensive condition, a hypotensive IAS results in incontinence. As a result, IAS dysfunction cannot be easily controlled, and treating a hypertensive or hypotensive IAS can be difficult.

Last year, Dr. Rattan’s group reported in the journal Gastroenterology that drugs that block the activity of an enzyme (Rho kinase) might hold a key to treating chronic and severe disorders such as certain forms of constipation, hemorrhoids, anal fissures, Hirschsprung’s disease and other similar gastrointestinal problems.

According to Dr. Rattan, the currently funded research is expected to have significant implications for both improved understanding and treatment of certain gastrointestinal disorders – especially those involving a hypertensive and hypotensive IAS.