Role of Platelet-Activating Factor in Glucose Uptake and Utilization of Different Tissues

Abstract

The purpose of the present study was to elucidate the role of platelet-activating factor (PAF) in influencing the glucose metabolism of selected rat tissues. The in vivo glucose utilization rate in different tissues assessed by the 2-deoxyglucose tracer technique was determined 80 min following the intravenous injection of human serum albumin in saline or intravenous administration of a known amount (130 ng/100 g BW) of PAF. PAF administration resulted in significant hyperglycemia (8.89 ± 0.29 mmol/l) and increased the in vivo glucose utilization rate by the polymorphonuclear leukocytes (435%), monocytes (218%), liver (58%), lung (53%), intestine (52%) and spleen (51%). Owing to the accentuated hyperglycemia the metabolic clearance rate (MCR) for glucose was also calculated; this rate is an indicator of the avidity of tissues for this metabolite. There were significantly elevated MCR values in the polymorphonuclear leukocytes (211%), monocytes (229%), spleen (79%), intestine (71%) and liver (67%). These findings indicate that tissue glucose metabolism is deeply affected by the administration of PAF and according to data obtained it is thought that this mediator may also be involved in the upregulation of host defense-related cellular functions.