Navigation Links
Erectile dysfunction drugs allowed more chemotherapy to reach brain tumors in laboratory study
Date:7/28/2008

LOS ANGELES (July 28, 2008) In a study using laboratory animals, researchers found that medications commonly prescribed for erectile dysfunction opened a mechanism called the blood-brain tumor barrier and increased delivery of cancer-fighting drugs to malignant brain tumors.

The experiments were conducted at Cedars-Sinai Medical Center's Maxine Dunitz Neurosurgical Institute and published in Brain Research.

Viagra (sildenafil) and Levitra (vardenafil) are known as PDE5 inhibitors because they block an enzyme, phosphodiesterase5, which interrupts a series of biochemical events that cause the decreased blood flow of erectile dysfunction. This laboratory rat study, published online ahead of print in the journal, found that similar biochemical interactions in the small vessels of the brain play a major role in the blood-brain tumor barrier, which impedes delivery of anti-tumor drugs into brain tumors. PDE5 inhibitors were found to open the barrier and increase drug transport in this early animal study.

Although the normal blood-brain barrier, which regulates access to the brain from the bloodstream, shares many characteristics with the blood-brain tumor barrier, the signaling mechanism blocked by PDE5 inhibitors is unique to the blood-brain tumor barrier. This allows the PDE5 inhibitors to selectively increase drug transport to malignant brain tumors without affecting normal brain tissue.

According to the researchers, these findings may have significant implications in improving drug delivery to brain tumors in patients.

"This is the first study to show that oral administration of PDE5 inhibitors increases the rate of transport of compounds across the blood-brain tumor barrier and improves the effectiveness of the anti-tumor drug adriamycin in the treatment of brain tumors in a rat model. We chose adriamycin for this study because it is one of the most effective drugs against brain tumor cell lines in the laboratory but it has very little effect in animals and humans because it is unable to cross the blood-brain tumor barrier. The combination of vardenafil and adriamycin resulted in longer survival and smaller tumor size," said neurosurgeon Keith L. Black, M.D., chairman of the Department of Neurosurgery at Cedars-Sinai Medical Center and director of the Maxine Dunitz Neurosurgical Institute.

Black, the article's first and corresponding author, has been recognized for his earlier groundbreaking work to break through the blood-brain tumor barrier with natural and synthetic bradykinin, a peptide that temporarily opens the barrier and increases anti-cancer drug delivery into certain tumors by more than 1,000 percent. In 2000, he received the Javits Neuroscience Investigator Award from the National Institute of Neurological Disorders and Stroke, part of the National Institutes of Health, for his blood-brain barrier research.

In the current studies, the blood-brain tumor barrier-opening effects of PDE5 lasted considerably longer than those of bradykinin and allowed greater transport across the barrier into tumor tissues. Because vardenafil was found to be more effective than sildenafil in increasing blood-brain tumor barrier permeability and transport, vardenafil was used in a survival study of 29 tumor-bearing rats. Those treated with saline (control) survived 32 days on average while those treated with vardenafil alone survived about 35 days and those treated with adriamycin alone survived about 42 days. When vardenafil was combined with adriamycin, rats survived an average 53 days.

Although the researchers exposed the laboratory animals to doses of sildenafil and vardenafil that are comparable to the dose range approved for erectile dysfunction in humans, there were no detectable side effects in the rats, and neither drug increased transport of tracers into normal brain tissue.


'/>"/>

Contact: Sandy Van
sandy@prpacific.com
800-880-2397
Cedars-Sinai Medical Center
Source:Eurekalert

Related medicine news :

1. Lots of Sex May Prevent Erectile Dysfunction
2. Erectile dysfunction lower in men who have intercourse more often
3. Gene Therapy May Treat Erectile Dysfunction
4. Erectile Dysfunction a Strong Harbinger of Heart Trouble
5. AUA 2008: Maxi-K gene transfer may prove to be safe and effective erectile dysfunction treatment
6. The Penis Diet: A Healthy Solution for Men Challenged by Erectile Dysfunction
7. FDA Approves Cialis(R) (tadalafil) for Once Daily Use for the Treatment of Erectile Dysfunction
8. Horphags Prelox(R) Provides Over-the-Counter Solution in Battle Against Erectile Dysfunction
9. Warner Chilcott and NexMed Sign U.S. Collaboration for Topical Alprostadil Treatment for Erectile Dysfunction
10. Diabetic Men With Erectile Dysfunction Urged to Consult Their Doctors During November - American Diabetes Month
11. Erectile Dysfunction: A Harbinger of Heart Trouble
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/26/2016)... ... May 26, 2016 , ... Despite last week’s media reports hinting at a ... to wait until March 2017 for an interest rate increase, according to Rajeev Dhawan ... Business. , “The Federal Open Market Committee (FOMC) dot charts are of interest to ...
(Date:5/26/2016)... St. Louis, Missouri (PRWEB) , ... May 26, ... ... optimal cost, quality and clinical outcomes, hosted members and suppliers for its inaugural ... with a focus on their mission of elevating the operational health of America’s ...
(Date:5/26/2016)... ... 26, 2016 , ... The Woodlands at John Knox Village , Florida’s ... care for living and healing, celebrated its grand opening, today. The Woodlands at John ... provided by Empowered Staff. , “This is an incredibly fulfilling time for John Knox ...
(Date:5/26/2016)... N.J. (PRWEB) , ... May 26, 2016 , ... ... delivery technologies and development solutions for drugs, biologics, consumer health and global clinical ... sales office in Korea to support the company’s continued investment and strategic growth ...
(Date:5/26/2016)... ... , ... Memorial Day Weekend marks the unofficial start of summer and the ... make sure your family and vehicle are ready to hit the road this weekend. ... deaths and an additional 50,500 serious injuries from motor vehicle crashes during the three-day ...
Breaking Medicine News(10 mins):
(Date:5/25/2016)... , May 25, 2016  Zymo Research Corp. ... their new reference materials that help researchers obtain ... collection to analyses. The rapid growth of the ... researchers to have standard methods to improve the ... Biases inherently exist at every step of the ...
(Date:5/25/2016)... May 25, 2016  Granger Diagnostics today announced immediate ... wounds and infections. This test ensures discovery of ... viruses. The test requires only a simple swab of ... David G. Bostwick , MD, Chief Medical ... wound healing: "We are excited to make available, ...
(Date:5/25/2016)... , May 25, 2016 ... H1 2016"market research report that provides an overview ... comparative analysis at various stages, therapeutics assessment by ... administration (RoA) and molecule type, along with latest ... also reviews key players involved in the therapeutic ...
Breaking Medicine Technology: