Cardiovascular Changes Induced By Drugs of Abuse

腺苷在咖啡因的行为影响中起作用，咖啡因是世界上使用最广泛的药物之一。我们之前已经证明腺苷A2A激动剂可以增加大鼠的心率，这种效果似乎是由中枢神经系统腺苷受体给药的。这种效应的作用部位被假设为孤束核（NTS）。为了进一步研究这种可能性，我们之前在NTS中植入了微透析探针，并给予腺苷激动剂CGS 21680。CGS 21680使NTS中谷氨酸水平升高，而腺苷A2A拮抗剂MSX-3使谷氨酸水平降低，提示腺苷对其有强直控制作用。CGS 21680和MSX-3的组合对谷氨酸没有影响。我们目前正在研究将CGS 21680注射到NTS中是否会产生类似于全身给药的心血管作用，以确认NTS调节腺苷激动剂的这些作用。

Adenosine plays a role in the behavioral effects of caffeine, one of the most widely used drugs in the world. We have previously shown that adenosine A2A agonists can increase heart rate in rats, an effect that appears to be medicated by CNS adenosine receptors. The site of action for this effect has been hypothesized to be the nucleus tractus solitarius (NTS). To investigate this possibility further, we previously implanted microdialysis probes in the NTS and administered the adenosine agonist CGS 21680. CGS 21680 produced an increase in the level of glutamate in the NTS, while the adenosine A2A antagonist MSX-3 produced a decrease of glutatmate, suggesting a tonic level of control by adenosine. The combination of CGS 21680 and MSX-3 produced no change in glutatmate. We are currently investigating whether the injection of CGS 21680 into the NTS will produce cardiovascular effects similar to systemic administration in an effort to confirm that the NTS regulates these effects of adenosine agonists.