[Study on beta-adrenoceptors mechanism of cadmium immunotoxicity].
OBJECTIVE
To study if the beta-adrenoceptors mechanism plays important role in the immunotoxicity of cadmium.


METHODS
The beta-adrenoceptor density, cellular cyclic adenosine 3',5' monophosphate (cAMP) levels, and DNA damage of rat spleen lymphocytes were studied. Beta-antagonist propranolol was used to block the beta-adrenoceptor.


RESULTS
In the single Cd administration group: beta-adrenoceptor density of spleen lymphocytes in the middle and high Cd concentration groups was higher than that in the non-Cd treated control group (P < 0.05), the levels of cAMP increased with the increase of Cd doses, and the result of the high Cd group was higher than that of the control group (P < 0.05). The proliferation function of T lymphocytes was lower in each Cd group than that in the control group (P < 0.05). Single cell gel electrophoresis (SCGE) detected that DNA damage of spleen lymphocytes in each Cd group were more severe than the control (P < 0.05). Pretreated with Pro group: After blocked with propranolol, beta-adrenoceptor density increased in the Pro control group and the density in all Cd treated groups was higher than the control group (P < 0.05), but all Cd treated groups showed no statistical significance than the Pro control group (P > 0.05). The cAMP levels, MTT and the subsets of T lymphocytes showed no statistical significance among all the groups (P > 0.05). The results of SCGE showed that DNA damage was most severe only in the high Cd group than other groups (P < 0.05).


CONCLUSIONS
The results suggest that the nerve-internal secretion system plays an important role in the immunotoxicity of cadmium, and the beta-adrenoceptor mechanism is important in the immunotoxic mechanism of cadmium.
Lu
C
C
Department of Environmental Health, Sun Yat-sen University of Medical Science, Guangzhou 510089, China.
Li
D
D
Dong
S
S
Lin
Z
Z
Chen
C
C
Yu
G
G
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D002104:Cadmium / Q000633:toxicity*; D020552:Comet Assay; D000242:Cyclic AMP / Q000378:metabolism; D004249:DNA Damage; D004305:Dose-Response Relationship, Drug; D008213:Lymphocyte Activation / Q000187:drug effects; D008297:Male; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*; D016176:T-Lymphocyte Subsets / Q000187:drug effects; D013601:T-Lymphocytes / Q000187:drug effects*
D000319:Adrenergic beta-Antagonists; D011943:Receptors, Adrenergic, beta; D002104:Cadmium; D011433:Propranolol; D000242:Cyclic AMP