The impact of hypothyroidism and thyroxine replacement on the expression of hepatic alpha 1-, alpha 2- and beta-adrenergic receptors in rat liver plasma membranes.
1. Liver plasma membranes were isolated from control, propylthiouracil-induced hypothyroid and thyroxine-replaced rats; relative specific activities of 5'-nucleotidase were found to be similar, 5.6-6.1, demonstrating that comparable purity levels were achieved. 2. Radioligand binding studies indicated that hepatic alpha 1-, alpha 2- and beta-adrenergic receptor binding to control liver membranes was 1963.23 +/- 59.34, 77.64 +/- 2.20 and 111.18 +/- 11.04 fmol.mg-1, respectively. 3. Hypothyroidism induced a 67% and 54% decrease, respectively, in hepatic alpha 1- and alpha 2-adrenergic receptor binding with no change in beta-adrenergic receptor binding. 4. Thyroxine replacement achieved an 85% and 100% restoration, respectively, in hepatic alpha 1- and alpha 2-adrenergic receptor expression with no effect on the beta-adrenergic receptor.
Sulakhe
S J
SJ
Department of Physiology, College of Medicine, University of Saskatchewan, Saskatoon, Canada.
Wilson
T R
TR
D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D005260:Female; D007037:Hypothyroidism / Q000378:metabolism*; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D011869:Radioligand Assay; D051381:Rats; D011916:Rats, Inbred F344; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects / Q000378:metabolism*; D011943:Receptors, Adrenergic, beta / Q000187:drug effects / Q000378:metabolism*; D013974:Thyroxine / Q000494:pharmacology*
D011942:Receptors, Adrenergic, alpha; D011943:Receptors, Adrenergic, beta; D013974:Thyroxine