Regional changes in cardiac and stellate ganglion norepinephrine transporter in DOCA-salt hypertension.
Uptake of norepinephrine via the neuronal norepinephrine transporter is reduced in the heart during deoxycorticosterone (DOCA)-salt hypertension. We hypothesized that this was due to reduced norepinephrine transporter mRNA and/or protein expression in the stellate ganglia and heart. After 4 weeks of DOCA-salt treatment there was no change in norepinephrine transporter mRNA in either the right or the left stellate ganglia from hypertensive rats (n=5-7, p>0.05). Norepinephrine transporter immunoreactivity in the left stellate ganglion was significantly increased (n=4, p<0.05) while the right stellate ganglion was unchanged (n=4, p>0.05). Whole heart norepinephrine content was significantly reduced in DOCA rats consistent with reduced uptake function; however, when norepinephrine was assessed by chamber, a significant decrease was noted only in the right atrium and right ventricle (n=6, p<0.05). Cardiac norepinephrine transport binding by chamber revealed that it was only reduced in the left atrium (n=5-7, p>0.05). Therefore, 1) contrary to our hypothesis reduced reuptake in the hypertensive heart is not exclusively due to an overall reduction in norepinephrine transporter mRNA or protein in the stellate ganglion or heart, and 2) norepinephrine transporter regulation occurs regionally in the heart and stellate ganglion in the hypertensive rat heart.
Department of Physiology, Michigan State University, East Lansing, MI, United States. Electronic address: ewehrwein@cns.msu.edu.
Erica A
EA
Wehrwein
Martin
M
Novotny
Greg M
GM
Swain
Lindsay M
LM
Parker
Mohammad
M
Esfahanian
John M
JM
Spitsbergen
Beth A
BA
Habecker
David L
DL
Kreulen
D000818:Animals; D064791:Desoxycorticosterone Acetate / Q000633:toxicity; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D006321:Heart / Q000502:physiology*; D006973:Hypertension / Q000139:chemically induced / Q000378:metabolism*; D007150:Immunohistochemistry; D008297:Male; D008901:Mineralocorticoids / Q000633:toxicity; D009206:Myocardium / Q000378:metabolism; D050484:Norepinephrine Plasma Membrane Transport Proteins / Q000096:biosynthesis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction; D017673:Sodium Chloride, Dietary / Q000633:toxicity; D013233:Stellate Ganglion / Q000378:metabolism*
D008901:Mineralocorticoids; D050484:Norepinephrine Plasma Membrane Transport Proteins; D017673:Sodium Chloride, Dietary; D064791:Desoxycorticosterone Acetate
Cardiac; Hypertension; NAT; NET; Noradrenaline; Stellate ganglion