Effect of pentylenetetrazol on the expression of tyrosine hydroxylase mRNA and norepinephrine and dopamine transporter mRNA

• Published in: Brain research. Molecular brain research. Vol. 44; no. 1; pp. 46 - 54
• Main Authors: Szot, Patricia, White, Sylvia S, Veith, Richard C
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-02-1997; Elsevier
• Subjects: Animals; Autoradiography; Biochemistry and metabolism; Biological and medical sciences; c- fos; Carrier Proteins - metabolism; Central nervous system; Dopamine Plasma Membrane Transport Proteins; Dose-Response Relationship, Drug; Fundamental and applied biological sciences. Psychology; Locus coeruleus; Male; Membrane Glycoproteins; Membrane Transport Proteins; Nerve Tissue Proteins; Neurotransporter; Norepinephrine - metabolism; Pentylenetetrazol; Pentylenetetrazole - pharmacology; Rats; Rats, Sprague-Dawley; RNA, Messenger - drug effects; Seizure; Substantia nigra; Tyrosine 3-Monooxygenase - metabolism; Ventral tegmentum area; Vertebrates: nervous system and sense organs; Ventral tegmentum area; Substantia nigra; Pentylenetetrazol; Seizure; Neurotransporter; c- fos; Locus coeruleus; Dopamine; Pentetrazol; Rat; Enzyme; Noradrenergic neuron; Rodentia; Central nervous system; Gene expression; Tyrosine 3-monooxygenase; Vertebrata; Mammalia; Locus niger; Convulsion; Convulsant agent; Dopaminergic neuron; Oxidoreductases; Carrier protein; Brain (vertebrata)
• ISSN: 0169-328X; 1872-6941
• DOI: 10.1016/S0169-328X(96)00217-3

Seizure activity has been shown to have differential effects on the terminal content of the monoamines, norepinephrine (NE) and dopamine (DA). Induction of seizure activity reduces the terminal content of NE, while DA levels remain unchanged or slightly elevated. This study examined the effect of the chemoconvulsant pentylenetetrazol (PTZ) on the mRNA expression of regulatory proteins which maintain the terminal content of NE and DA (i.e., synthesis and re-uptake). The areas examined were the noradrenergic neurons of the locus coeruleus (LC) and dopaminergic neurons of the substantia nigra pars compacta/ventral tegmentum area (SNpc/VTA) in the rat. In the LC, PTZ increased mRNA expression of the immediate early gene, c-
fos, and mRNA expression of the synthesizing enzyme, tyrosine hydroxylase (TH), and the re-uptake protein, norepinephrine transporter (NET). This effect on TH and NET was observed only 1 day after the administration of PTZ. In contrast, PTZ did not alter the expression of c-
fos mRNA in the SNpc/VTA, but reduced the expression of the dopamine transporter (DAT) mRNA. This effect was observed only 1 day after the administration of PTZ. TH mRNA expression in dopaminergic neurons was elevated initially in a manner similar to that observed in the LC. However, the effect of PTZ on TH mRNA expression in dopaminergic neurons was more prolonged (still elevated 3 days later). These results indicate that the chemoconvulsant PTZ has differential effects on the mRNA expression of regulatory systems (TH and neurotransporter proteins) in noradrenergic and dopaminergic neurons.