Laborartory studies in mice have shown that a drug called
intracellular sigma peptide (ISP) has promising results in restoring functions
like the ability to walk, to balance and urinate, lost due to paralyzing injury
to the spinal cord.
Scientists are hoping that with further studies ISP could be
used for therapy in humans. Jerry Silver, a professor of neurosciences at Case
Western Reserve University in Cleveland, Ohio said, "We're very excited at
the possibility that millions of people could, one day, regain movements lost
during spinal cord injuries."
The research looked at ways of overcoming scarring when
nerve fibers in the spinal cord are damaged and signals from the brain no
longer reach muscles below the injury site. Nerve fibers try to cross the
injury site and reconnect with other fibers, but become trapped at the scar
site by sticky proteins called proteoglycans. ISP is designed to act on the
receptor on the surface of the nerve cells which turns off a response to the
proteoglycans that causes the blockage. ISP induced 'sprouting' of these fibers
below the injury site.
During the experiment, 26 rats were given severe spinal cord
injuries followed by daily injections of ISP for seven weeks. 21 of the 26
regained one or more of three functions - the ability to walk, to balance and
to control when and how much they urinated. Some of them regained all three,
others one or two, and five none of the functions.
The study is published in the journal Nature.