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Investigations on a Plasminogen Activator in Two Blood‐Suckers, Rhodnius prolixus Stål and Hirudo medicinalis
Author(s) -
Hawkins Rosemary I.,
Hellmann K.
Publication year - 1966
Publication title -
british journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.907
H-Index - 186
eISSN - 1365-2141
pISSN - 0007-1048
DOI - 10.1111/j.1365-2141.1966.tb00130.x
Subject(s) - rhodnius prolixus , fibrinolysin , hirudo medicinalis , leech , biology , blood meal , insect , zoology , plasmin , biochemistry , ecology , world wide web , computer science , enzyme
I n a previous paper (Hellmann and Hawkins, 1964) we described two anticoagulants and a fibrinolytic activity extractable from an insect, the blood‐sucking Hemipteran Rhodnius prolixus . In the present paper we report further experiments to characterize the fibrinolysin and to trace its source. The properties of the two anticoagulants have been described more fully elsewhere (Hellmann and Hawkins, 1965). The fibrinolysin was originally found in the gut of the insect; of four possible sources from which it could reach the gut, the gut wall and the salivary glands have already been shown to be devoid of activity (Hellmann and Hawkins, 1964). The two remaining possibilities, the blood meal and organisms present in the gut, are examined below. The possibility that the fibrinolysin was an exo‐product of the symbiotic organism Nocardia rhodnii , which occurs in the gut of R. prolixus (Baines, 1956) was strengthened by the lack of activity found in insects from which this organism had disappeared. By culturing N. rhodnii on artificial media it was possible to examine this idea directly. Our original assumption that a fibrinolysin might be involved in dealing with the meal taken in by a blood‐sucking animal proved well founded in the case of R. prolixus (Hellmann and Hawkins, 1964) and we therefore extended out investigation to the leech Hirudo medicinalis since, if the assumption was generally correct, as one of the larger blood‐sucking animals, it might be expected to be a potentially better source of fibrinolysin.