The Biological Significance of Haemoglobin in Nematode Parasites II. The Properties of the Haemoglobins as Studied in Living Pabasites

Abstract

In the parasites examined, the amounts of water-soluble haematin compounds, of which haemoglobin formed the large part, varied considerably; Nippo$rongylus murls contained about 6 mg. (as haematin) per g. dry wt. of tissue, Nematodirus spp. and Haemonchus contortus about 0.8 mg. per g. dry wt. Evidence is presented which indicates that the haemoglobin of Nippo$rongylus muris may be oxygenated in vivo, at least sometimes. The haemoglobin in the living parasites was easily oxygenated and deoxygenated; when the oxygen tension in the medium surrounding the parasites in vitro at 37°C. fell below about 13 mm. of mercury (Nippostrongylus muris) or 9 mm. of mercury (Haemonchus contortus and Nematodirus spp.) the oxyhaemoglobin became deoxygenated.