Alterations of tryptophan metabolism in a rat strain (Osborne-Mendel) predisposed to obesity.
1. Osborne-Mendel (O-M) rats displayed differences in brain and systemic tryptophan metabolism. O-M rats had decreased brainstem tryptophan-5-hydroxylase activity and decreased serotonin (5-HT) levels as compared to Sprague-Dawley rats. However, brain tryptophan levels were actually increased in O-M rats. Norepinephrine, dopamine and 5-hydroxyindole-3-acetic acid levels were not different between strains. 2. Pineal serotonin levels were increased in O-M rats. 3. Liver tryptophan 2,3-dioxygenase activity was increased in O-M rats while tyrosine aminotransferase activity was not different between strains. 4. Total blood cholesterol was decreased in O-M rats while triglycerides, free fatty acids and albumin was not different between strains. Total serum tryptophan was not different between strains while O-M rats had an increased level of free (unbound) tryptophan.
D000818:Animals; D001921:Brain / Q000378:metabolism; D005260:Female; D008099:Liver / Q000378:metabolism; D009765:Obesity / Q000235:genetics / Q000378:metabolism*; D010870:Pineal Gland / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011922:Rats, Mutant Strains / Q000378:metabolism*; D012701:Serotonin / Q000378:metabolism; D014364:Tryptophan / Q000378:metabolism*
D012701:Serotonin; D014364:Tryptophan