Carratù M R, Conte-Camerino D, De Serio A, Ferrari E, Mitolo-Chieppa D
Institute of Pharmacology, Medical Faculty, University of Bari, Italy.
J Auton Nerv Syst. 1989 Aug;27(3):221-8. doi: 10.1016/0165-1838(89)90115-x.
The present work is focused on the effects of newly developed dopaminergic agonists and antagonists on the field-stimulated vas deferens. Both LY 171555 and SK&F 38393, relatively selective DA2 and DA1 receptor agonists, respectively, produced concentration-dependent inhibition of the field stimulation-evoked contractions in the mouse vas deferens; both compounds did not modify the baseline tone nor the contractile responses to exogenous noradrenaline. Control LY 171555 and SK&F 38393 concentration-response curves, were shifted rightward in a parallel manner in the presence of sulpiride (relatively specific DA2 antagonist) and SCH 23390 (relatively specific DA1 antagonist), respectively. Control concentration-response curves for dopaminergic agonists were not modified in the presence of specific blockers for H1 and H2 histamine receptors, serotonin receptors and alpha 2-adrenoceptors. These preliminary findings are suggestive of the existence of two dopaminergic receptor types both presumably located prejunctionally.
目前的工作聚焦于新开发的多巴胺能激动剂和拮抗剂对电场刺激输精管的影响。LY 171555和SK&F 38393分别是相对选择性的DA2和DA1受体激动剂，二者均可使小鼠输精管中电场刺激诱发的收缩产生浓度依赖性抑制；这两种化合物均不改变基础张力，也不改变对外源性去甲肾上腺素的收缩反应。分别在存在舒必利（相对特异性的DA2拮抗剂）和SCH 23390（相对特异性的DA1拮抗剂）的情况下，对照LY 171555和SK&F 38393的浓度-反应曲线以平行方式向右移动。多巴胺能激动剂的对照浓度-反应曲线在存在组胺H1和H2受体、5-羟色胺受体及α2-肾上腺素受体的特异性阻断剂时未发生改变。这些初步研究结果提示可能存在两种均位于神经节前的多巴胺能受体类型。
