[Determination of hepatocyte adrenergic alpha 1 receptor and study on actions of nourishing yin and replenishing qi drugs in experimental hyperthyroid rats].
In this study, hyperthyroid rat models (group 1) were established by daily intramuscular injections of thyroxine for 7 days. Group 2 were hyperthyroid rats receiving at the same time Nourishing Yin and Replenishing Qi drugs (Ophiopogonis japonis, Pseudostellariae heterophylla and Rehmannia glutinosa). Normal rats served as controls. Group 1 and group 2 rats showed manifestations of hyperthyroidism, higher rectal temperature, increased O2 consumption, as well as significantly higher serum TT3 and TT4 levels. Receptor proteins of liver cell membrane were prepared. Receptor binding assay was performed using 3H-prazosin (adrenergic alpha 1 receptor antagonist) as radioligand, maximal binding capacity (Bmax) and dissociation constant (Kd) were calculated from Scatchard curve. It was found Bmax (fmol/mg protein) in model groups were lower than that of the control group, but the differences were not statistically significant. Kd (nM) in group 1 was significantly lower than that of control group (2.32 +/- 1.09 vs 5.42 +/- 2.54, P < 0.05), indicating that receptor affinity was increased in hyperthyroid rats. Kd in group 2 (3.11 +/- 1.48) was intermediate between that in group 1 and controls, suggesting that these Chinese herbal medicine might have an effect in lowering receptor affinity and the peripheral conversion of T4 to T3.
Shan
J C
JC
First Affiliated Hospital, Sun Yat-sen University of Med. Sci, Guangzhou.
D000818:Animals; D004365:Drugs, Chinese Herbal / Q000627:therapeutic use*; D006980:Hyperthyroidism / Q000139:chemically induced / Q000188:drug therapy* / Q000378:metabolism; D007273:Injections, Intramuscular; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D008297:Male; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D018340:Receptors, Adrenergic, alpha-1 / Q000378:metabolism*; D013974:Thyroxine
D004365:Drugs, Chinese Herbal; D018340:Receptors, Adrenergic, alpha-1; D013974:Thyroxine