Effects of single and multiple dose LSD on endogenous levels of brain tyrosine and catecholamines.
The effects on brain catecholamines of seven daily doses of d-LSD 520 mug/kg injected i.p. to Sprague-Dawley rats on a tolerance dosage schedule (L X 7) were compared with the effects of a single dose of LSD (L X 1) 520 mug/kg or 1040 mug/kg, over a 90 min time course. Compared to saline controls, after a single dose of 520 mug/kg LSD, there was a significant decrease in brain norepinephrine at 30 to 60 min, a rise in dopamine at 60 min, and a small rise in brain tyrosine at early time points followed by significant decline from control levels after 60 min. The effects of a single dose of 1040 mug/kg LSD were similar to the 520 mug/kg dose but were greater in both magnitude and duration of the brain catecholamine changes. After a tolerance dosage schedule there were significant changes in the response of brain catecholamines to 520 mug/kg LSD. The rise in brain dopamine at 60 min was abolished, brain tyrosine was uniformly below both saline and L times 1 animals, and brain norepinephrine returned to control levels slightly faster.
D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects*; D002395:Catecholamines / Q000032:analysis*; D004298:Dopamine / Q000032:analysis; D004305:Dose-Response Relationship, Drug; D008238:Lysergic Acid Diethylamide / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D009638:Norepinephrine / Q000032:analysis; D051381:Rats; D013997:Time Factors; D014443:Tyrosine / Q000032:analysis*
D002395:Catecholamines; D014443:Tyrosine; D008238:Lysergic Acid Diethylamide; D004298:Dopamine; D009638:Norepinephrine