Effects of dopamine beta-hydroxylase genotype and disulfiram inhibition on catecholamine homeostasis in mice.
BACKGROUND
Dopamine beta-hydroxylase (DBH) converts dopamine (DA) to norepinephrine (NE), thus playing a critical role in catecholamine metabolism.


OBJECTIVE
We examined the effects of Dbh gene dosage and the DBH inhibitor disulfiram in mice with zero, one, or two null Dbh alleles (+/+, +/-, and-/- mice).


RESULTS
DBH protein levels in adrenal and prefrontal cortex (PFC) and adrenal DBH activity were proportional to number of wild-type alleles. Adrenal DA was slightly increased in+/- mice and markedly increased (80-fold) in -/- mice compared to wild-type animals. While adrenal NE and epinephrine (EPI) were undetectable in -/- mice, adrenal concentrations of NE and EPI were similar in +/+ and +/- mice, suggesting that the increase in DA maintains the normal rate of beta-hydroxylation in Dbh +/- mice. Disulfiram had little effect on adrenal catecholamine levels, regardless of genotype or dose. NE was absent in the PFC of -/- mice, but only slightly reduced in +/- animals compared to wild-type animals. PFC DA was increased twofold in +/- mice and fivefold in -/- mice, and the NE to DA ratio was reduced ( approximately 35%) in +/- mice, compared to wild-type mice. Disulfiram significantly decreased PFC NE and increased DA in +/+ and +/- animals, with the disulfiram and genotype effects on the PFC NE to DA ratio apparently additive.


CONCLUSIONS
The data reveal potentially important and apparently additive effects of Dbh genotype and disulfiram administration on PFC catecholamine metabolism. These effects may have implications for genetic control of DBH activity in humans and for understanding therapeutic effects of disulfiram.
Bourdélat-Parks
Brooke N
BN
Department of Human Genetics, Emory University School of Medicine, Whitehead 301, 615 Michael St., Atlanta, GA 30322, USA. dweinshenker@genetics.emory.edu.
Anderson
George M
GM
Donaldson
Zoe R
ZR
Weiss
Jay M
JM
Bonsall
Robert W
RW
Emery
Milburn S
MS
Liles
L Cameron
LC
Weinshenker
David
D
D000302:Adrenal Cortex / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D002395:Catecholamines / Q000378:metabolism*; D004221:Disulfiram / Q000494:pharmacology*; D004298:Dopamine / Q000378:metabolism; D004299:Dopamine beta-Hydroxylase / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004837:Epinephrine / Q000378:metabolism; D005260:Female; D005838:Genotype; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009638:Norepinephrine / Q000378:metabolism; D010597:Pharmacogenetics; D017397:Prefrontal Cortex / Q000187:drug effects / Q000378:metabolism; D012701:Serotonin / Q000378:metabolism
D002395:Catecholamines; D004791:Enzyme Inhibitors; D012701:Serotonin; D004299:Dopamine beta-Hydroxylase; D004221:Disulfiram; D004298:Dopamine; D009638:Norepinephrine; D004837:Epinephrine