[Cardiovascular response caused by intracerebroventricular microinjection of interleukin-2].

AIM

To investigate the cardiovascular response caused by intracerebroventricular (ICV) microinjection of interleukin-2 (IL-2) and explore the underlying mechanism.

METHODS

Male Sprague-Dawley rats were anesthetized with intraperitoneal urethane( 1.2 g/ kg). The changes of mean arterial blood pressure (MAP) and heart rate (HR) were observed during ICV microinjection of IL-2 with or without pretreatment of naloxone or atropine or phentolamine.

RESULTS

There were no significant effects on cardiovascular response after ICV injection of IL-2 at 500 IU/3 microl and 1 000 IU/3 microl, but IL-2 at 1 500 IU/3 microl could elevate MAP and HR. The responses of MAP and HR reached their maximum levels at 10 min (MAP: 10 +/- 1.8 mmHg, HR: 25 +/- 2 b/min, P < 0.05) after the injection and lasted 15 or 10 minutes respectively. Pretreatment with naloxone (10 microg/10 microl) or atropine (1.5 microg/10 microl) could block the cardiovascular response of ICV injection of IL-2. Pretreatment with phentolamine (10 microg/10 microl) failed to block the cardiovascular responses by IL-2.

CONCLUSION

ICV microinjection of interleukin-2 (IL-2) can elevate the MAP and HR, which may be mediated by central opioid and cholinergic system. The alpha-adrenergic system may be not involved in the cardiovascular response of IL-2.