The impact of the cytokines on cardiovascular system has been very controversial for decades. Cytokines are mainly released during immune responses to antigens. In some circumstances such as toxic shock during super-antigen stimulation, high level of cytokines are released which may have dramatic impact on cardiovascular system; Therefore in the present study we have studied the effects of supernatant of Phytohemaglotinin (PHA)-stimulated lymphocytes on isolated heart in rat. The isolated human peripheral blood mononuclear cells (PBMCs) were stimulated by PHA in vitro for three days and then the supernatants were harvested.
Three dilutions of supernatants (1/800, 1/400 and 1/200) on isolated heart were used. Each concentration was infused to the heart for 10 minutes and the heart rate and the intarventricular pressure was recorded for 40 minutes. The highest dilution, 1/800, reduced the heart rate 1 and 2 minute after infusion significantly. This effect was significant 10 minutes after infusion for 1/400 and 1/200 dilutions as well. Moreover, the supernatant in highest dilution, 1/800, reduced the Max dp/dt and increased Min dp/dt and Min LV significantly.
In general the data shows that the supernatant has a negative inotropic and chronotropic effects on isolated rat heart.