The Lipid Moiety of Haemozoin (Malaria Pigment) and P. falciparum Parasitised Red Blood Cells Bind Synthetic and Native Endothelin-1

Table 1

Absorption of ET-1 by pRBC (D10 strain) or haemozoin: comparison between fluorimetric detection and ELISA assay.

	ET-1 recovery
	Fluorescence spectroscopy		ELISA
Samples	Fluorescence Intensity (AUC)	% control	pmol/mL	% control
Control^a	41305		9.04
Normal RBC	40503	98.1	8.69	96.1
pRBC (D10 1.6%)	32224	78.0	5.93	65.5
pRBC (D10 3.2%)	30784	74.5	5.03	55.6

Data of a representative experiment out of three experiments performed in the same conditions. ET-1 (10 pmol/mL) was incubated for 18 hours in PBS or in the presence of normal RBC or pRBC (D10 strain at 1.6% and 3.2% parasitaemia). ^aControl samples for fluorescence spectroscopy were prepared by diluting ET-1 in the supernatant recovered by centrifugation of a suspension of normal RBC incubated in PBS for the same length of time. Control samples for ELISA test were prepared by diluting ET-1 in PBS. At the end of the incubation, RBCs were centrifuged and supernatants used for ET-1 determination by both methods.
Data are expressed as arbitrary fluorescent units (AUC Area Under the Curve) or as pmol/mL.