From: young@serum.kodak.com (Rich Young)
Subject: animals in research (are these justifiable?)
Originator: young@sasquatch
Reply-To: young@serum.kodak.com
Organization: Clinical Diagnostics Division, Eastman Kodak Company
Date: Tue, 10 Nov 92 16:55:48 GMT

From SCIENCE NEWS: Vol. 142, No. 19, November 7, 1992, page 311 (quoted with-
out permission and edited for brevity):

	   A team of neuroscientists led by Sarah F. Leibowitz at Rockefeller
	University in New York City has uncovered evidence in rats that a
	brain protein called galanin dictates the craving for fatty foods.
	Moreover, the group has found that a drug that blocks galanin's
	activity can reduce an animal's appetite for fat.
	   Leibowitz's team found that rats with high natural concentrations
	of galanin in a brain region called the hypothalamus at more lard
	each day and gained more weight over the study period than did rats
	with low galanin concentrations -- despite the fact that both groups
	consumed roughly the same amount of protein and carbohydrate each
	day.  In addition, the researchers observed, the rats with high
	galanin levels almost always began their meals by lapping up lard,
	indicating that they might be trying to satisfy a craving.
	   In a second study reported at the [Society for Neuroscience's
	annual meeting], Leibowitz' group ruled out the possibility that
	the extra galanin might have arisen elsewhere in the rats' bodies
	and then traveled to their brains.  They also found that [rats with
	high galanin concentrations] had reduced concentrations of insulin
	in the blood, indicating that galanin serves as a biochemical link
	between obesity and diabetes.  Her team has not yet determined how
	galanin and insulin interact.
	   Leibowitz [says] that earlier experiments by her group and others
	have shown that rats receiving galanin injections in a specific
	region of their hypothalamus eat much more fat than do control rats
	given galanin injections elsewhere in their brains.  Moreover, she 
	says, the galanin injections make the fat-gobbling rats sluggish,
	reducing their metabolism and leading to weight gain.
	   Leibowitz and her colleagues have recently fouond that an experi-
	mental drug called M40 can slash a rat's fat craving by blocking
	the activity of galanin in its hypothalamus.  In the November/
	December BRAIN RESEARCH, she and Rockefeller colleague Taewan Kim
	report that rats given extra galanin to boost their fat intake
	resume eating normal amounts of fat following injections of M40.

And also....

	   Skin cells genetically engineered to produce a protein called
	nerve growth factor (NGF) can spur the regrowth of nerves within a
	partially severed spinal cord, according to a new study involving
	rats.  The technique offers hope as a means of treating spinal cord
	injuries in humans.
	   A group led by Mark H. Tuszynski of the University of California,
	San Diego, inserted the gene for either NGF or a control, marker
	enzyme into fibroblasts isolated from the skin of adult rats.  The
	researchers then injected slurries of cells containing either the
	NGF gene or the marker gene into the partially severed spinal cords
	of two groups of rats.
	   Because fibroblasts normally secrete collagen and fibronectin --
	two major constituents of connective tissue -- Tuszynski and his
	colleagues predicted the cells would generate connective-tissue
	bridges to heal the rats' spinal cords.  In addition, they hoped
	that the NGF-containing cells would stimulate severed nerves within
	the rats' spinal cords to grow across the injured gap and rejoin.
	   When Tuszynski's group examined the rats two weeks after implanting
	the cell grafts, they found that both types of cell implant had
	survived and grown.  Moreover, Tuszynski reported at the [annual
	meeting of the Society for Neuroscience], the rats that had received
	cells containing the NGF gene showed signs of nerve-cell regeneration.
	   Tuszynski says the new technique may obviate the need for nervous
	tissue from aborted human fetuses, which has shown promise in 
	repairing patients' damaged spinal cords.
	   Tuszynski also notes that the procedure would avoid tissue
	rejection problems because physicians could treat spinal cord
	problems using genetically engineered fibroblasts taken from a 
	patient's own skin.



-Rich Young (These are not Kodak's opinions.)
Newsgroups: talk.politics.animals