Effects of electroconvulsive shock on tetrahydrobiopterin and GTP-cyclohydrolase activity in the brain and adrenal gland of the rat.
The effects of a single and repeated electroconvulsive shock (ECS) (300 mA, 0.2 s) on tetrahydrobiopterin (BH4) levels and GTP-cyclohydrolase activity in the brain and adrenal glands of rats were examined. Twenty-four hours after the last ECS treatment (one/day for 7 days), biopterin levels were significantly elevated in the locus coeruleus, hippocampus, frontal cortex, hypothalamus, ventral tegmental area, and adrenal gland. There were no changes in biopterin levels after a single application of ECS. GTP-cyclohydrolase activity was significantly increased in the locus coeruleus, frontal cortex, hippocampus, hypothalamus, and adrenal gland 24 h after repeated ECS and remained elevated in certain tissues up to 8 days after the last treatment. Kinetic analysis of adrenal and locus coeruleus GTP-cyclohydrolase 1 day after 7 days of ECS showed significant changes in both Km and Vmax values. These data suggest that the long-term increases in BH4 levels and GTP-cyclohydrolase activity after repeated ECS may play a part in the mediation of the antidepressant effects of ECS.
Hossain
M A
MA
University of Colorado Health Sciences Center, Department of Pharmacology, Denver 80262.
Masserano
J M
JM
Weiner
N
N
D000311:Adrenal Glands / Q000737:chemistry / Q000201:enzymology / Q000378:metabolism*; D000818:Animals; D001708:Biopterins / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism; D001921:Brain / Q000201:enzymology / Q000378:metabolism*; D001923:Brain Chemistry; D004597:Electroshock; D006136:GTP Cyclohydrolase / Q000032:analysis / Q000378:metabolism*; D006624:Hippocampus / Q000737:chemistry / Q000201:enzymology / Q000378:metabolism; D007031:Hypothalamus / Q000737:chemistry / Q000201:enzymology / Q000378:metabolism; D008125:Locus Coeruleus / Q000737:chemistry / Q000201:enzymology / Q000378:metabolism; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
D001708:Biopterins; D006136:GTP Cyclohydrolase; C003402:sapropterin