Effect of exercise on mRNA expression of select adrenal medullary catecholamine biosynthetic enzymes.
The effect of submaximal endurance training (SET) on sympathoadrenal activity is not clear. We tested the hypothesis that SET (90 min/day, 5 days/wk, for 12 wk) elevates mRNA expression of catecholamine (CA) biosynthetic enzymes, tyrosine hydroxylase (TH) and dopamine-beta-hydroxylase (DbetaH) in the adrenal medullae of adult, female Sprague-Dawley rats. SET increased TH protein level by 35%, TH activity by 62%, TH mRNA expression by 40%, and DbetaH mRNA expression by 67%. In addition, we examined the effect of SET on Fos-related antigens (FRAs), FRA-2 immunoreactivity, and activator protein (AP)-1 binding activity. SET increased AP-1 binding activity by 78%; however, it did not affect late FRAs and FRA-2 immunoreactivity. Because the regulation of neuropeptide Y (NPY) often parallels that of CAs, we also examined the effect of SET on NPY mRNA expression. Indeed, SET elevated NPY mRNA expression as well. We conclude that 1) SET elicits a pretranslational stimulatory effect on adrenomedullary CA biosynthetic enzymes, 2) another immediate early mRNA product, rather than FRA-2, may contribute to the increase in AP-1 binding activity in response to SET, and 3) SET increases NPY mRNA expression.
Erdem
S Remzi
SR
Department of Pharmacology and Therapeutics, University of Florida College of Medicine, Gainesville, Florida 32610, USA.
Demirel
Haydar A
HA
Broxson
Christopher S
CS
Nankova
Bistra B
BB
Sabban
Esther L
EL
Tümer
Nihal
N
D000313:Adrenal Medulla / Q000033:anatomy & histology / Q000201:enzymology*; D000818:Animals; D000906:Antibodies; D001835:Body Weight; D004268:DNA-Binding Proteins / Q000032:analysis / Q000235:genetics / Q000276:immunology; D004299:Dopamine beta-Hydroxylase / Q000235:genetics*; D005260:Female; D051921:Fos-Related Antigen-2; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology; D009478:Neuropeptide Y / Q000235:genetics; D009929:Organ Size; D010805:Physical Conditioning, Animal / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D018808:Transcription Factor AP-1 / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000032:analysis / Q000235:genetics / Q000276:immunology; D014446:Tyrosine 3-Monooxygenase / Q000235:genetics* / Q000378:metabolism
D000906:Antibodies; D004268:DNA-Binding Proteins; D051921:Fos-Related Antigen-2; C497874:Fosl2 protein, rat; D009478:Neuropeptide Y; D012333:RNA, Messenger; D018808:Transcription Factor AP-1; D014157:Transcription Factors; D014446:Tyrosine 3-Monooxygenase; D004299:Dopamine beta-Hydroxylase