THE HYPOTHYROID RAT AS A MODEL OF INCREASED SENSITIVITY TO DOPAMINE RECEPTOR AGONISTS

被引:8
作者
CAMERON, DL
CROCKER, AD
机构
[1] FLINDERS UNIV, MED CTR, SCH MED, DEPT CLIN PHARMACOL, BEDFORD PK, SA 5042, AUSTRALIA
[2] FLINDERS UNIV, MED CTR, SCH MED, CTR NEUROSCI, BEDFORD PK, SA 5042, AUSTRALIA
基金
英国医学研究理事会;
关键词
DOPAMINE; BEHAVIOR; D1-RECEPTOR; D2-RECEPTOR; THYROID HORMONES; HYPOTHYROIDISM; AGONIST SENSITIVITY; RAT;
D O I
10.1016/0091-3057(90)90537-R
中图分类号
B84 [心理学]; C [社会科学总论]; Q98 [人类学];
学科分类号
03 ; 0303 ; 030303 ; 04 ; 0402 ;
摘要
Control and hypothyroid rats were challenged with a range of doses (0.5-4-mu-mol/kg) of either the nonselective dopamine agonist, apomorphine, or the selective D2 receptor agonist, LY 171555, and their stereotyped head-down sniffing (SHDS) responses measured. The dose-response curves for both agonists were shifted to the left in the hypothyroid rats compared to water-treated controls. Increasing doses of the selective D2 antagonist, raclopride, caused a parallel shift to the right in the LY 171555-induced SHDS dose-response curve. Schild analysis revealed a decreased sensitivity to raclopride in the hypothyroid animals. The selective D1 antagonist SCH 23390 was observed to decrease the maximal response elicited by LY 171555 in a dose-dependent manner and the hypothyroid rats were more sensitive to this effect. It was concluded that hypothyroid rats showed an apparent increased sensitivity to D2 receptor agonists and a decreased sensitivity to D2 antagonists. In addition, the facilitation effect of the D1 receptor on the D2 receptor appeared less tightly coupled in the hypothyroid rats.
引用
收藏
页码:627 / 632
页数:6
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