Intraventricular insulin increases dopamine transporter mRNA in rat VTA/substantia nigra.
The hormone insulin can down-regulate the function and synthesis of the re-uptake transporter for norepinephrine (NET) in vivo and in vitro. In the present study we tested whether this action of insulin is generalized to another member of the catecholamine transporter family. We determined the level of dopamine transporter (DAT) mRNA expression in the ventral tegmental area (VTA)/substantia nigra compacta (SNc) of rats which were chronically treated with vehicle or insulin via the third cerebral ventricle (i.c.v.). DAT mRNA was significantly elevated in the VTA/SNc of rats treated with insulin, as compared with levels in vehicle-treated rats. This is in contrast to our previous observation that i.c.v. insulin decreases NET mRNA in the rat locus coeruleus, and suggests that insulin may have differential and specific modulatory effects on CNS catecholaminergic pathways.
Figlewicz
D P
DP
Department of Cell Biology, Oregon Health Sciences University, Portland 97201.
Szot
P
P
Chavez
M
M
Woods
S C
SC
Veith
R C
RC
D000818:Animals; D002352:Carrier Proteins / Q000096:biosynthesis*; D004298:Dopamine / Q000378:metabolism*; D050483:Dopamine Plasma Membrane Transport Proteins; D017403:In Situ Hybridization; D007276:Injections, Intraventricular; D007328:Insulin / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger / Q000096:biosynthesis*; D051381:Rats; D013378:Substantia Nigra / Q000187:drug effects / Q000378:metabolism*; D013462:Sulfur Radioisotopes; D017557:Ventral Tegmental Area / Q000187:drug effects / Q000378:metabolism*
D002352:Carrier Proteins; D050483:Dopamine Plasma Membrane Transport Proteins; D007328:Insulin; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; C493216:Slc6a3 protein, rat; D013462:Sulfur Radioisotopes; D004298:Dopamine