Cardiac derived neutrophil chemotactic factors; preliminary biochemical characterization.
The purpose of this study is to investigate whether isolated hearts perfused with cardioplegic solution release inflammatory mediators such as neutrophil chemotactic factors (NCF). Three conditions were tested, including: (1) perfusion of rabbit hearts with crystalloid cardioplegic solution (4 degree C) saturated with air (95% oxygen) and containing dextrose (i.e. complete system), (2) perfusion of rabbit hearts with non-oxygenated cardioplegic solution, containing dextrose (i.e. minus oxygen system), and (3) perfusion of hearts with cold cardioplegic solution saturated with air in the absence of dextrose (i.e. minus dextrose system). At various time intervals (5 min, 1, 2, 3 and 4 h) samples of circulated perfusate were removed and assayed for the presence of NCF using modified Boyden chambers. Rabbit peritoneal neutrophils were the indicator cells. The standard chemoattractant, f-Met-Leu-Phe (f-MLP) was the positive control. High levels of neutrophil chemotactic activity were detected in perfusate of all above described hearts perfused for 4 h (i.e. 194 +/- 22% of f-MLP control--complete system, 126 +/- 13%--minus oxygen and 136 +/- 10%-minus dextrose). Histological evaluation of these hearts showed evidence of global ischemia. We also detected significant levels of NCF in effluent of hearts perfused for 5 min, 1, 2 and 3 h. Similar to perfused hearts, isolated rabbit hearts incubated for 4 h with non-oxygenated cardioplegic solution (in presence and absence of dextrose) released high levels of NCF (132 +/- 18%-intact heart; and 100 +/- 6% myocardial segments). Standard checkerboard analysis revealed that the observed activity released from these hearts is chemotactic.(ABSTRACT TRUNCATED AT 250 WORDS)