Change of cardiac beta-adrenoceptors in lead-exposed rats.
The effect of lead on cardiac beta-adrenoceptors was studied. Wistar rats used in these trials were divided into seven groups of ten animals each (A-G). Of these, groups B was given drinking water containing 0.01% lead acetate, group C 0.05%, group D 0.1%, group E 0.5%, group F 1% and group G 2% for a period of 60 days. Group A was given pure water. A radioligand-binding assay fulfilling strict criteria of receptor affinity and density was used to quantify cardiac beta-adrenoceptors. Application of a trend test indicated that both blood and heart lead levels increased significantly from group A to group G (A < G), but that beta-adrenoceptor density decreased (G < A), whereas Kd did not vary among the seven groups. Linear regression analysis showed that decrease of cardiac beta-adrenergic receptor density was closely related to elevation of blood and heart lead levels. The results show that lead exposure results in a reduction of cardiac beta-adrenoceptor density.
Chang
H R
HR
Department of Cosmetic Science, Chia-Nan College of Pharmacy and Science, Tainan County, Taiwan.
Chen
S S
SS
Tsao
D A
DA
Cheng
J T
JT
Ho
C K
CK
Yu
H S
HS
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D020120:Iodocyanopindolol; D007854:Lead / Q000032:analysis / Q000097:blood / Q000633:toxicity*; D009206:Myocardium / Q000737:chemistry / Q000378:metabolism; D009929:Organ Size / Q000187:drug effects; D009942:Organometallic Compounds / Q000633:toxicity*; D010869:Pindolol / Q000031:analogs & derivatives / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D011943:Receptors, Adrenergic, beta / Q000187:drug effects* / Q000378:metabolism
D009942:Organometallic Compounds; D011943:Receptors, Adrenergic, beta; D007854:Lead; D020120:Iodocyanopindolol; D010869:Pindolol; C008261:lead acetate