KININ, KININOGEN AND KININASE LEVELS DURING ACUTE Babesia bovis (=B. argentina) INFECTION OF CATTLE

Abstract

1Kinin levels began rising on day 3 after infection of cattle with Babesia bovis (=B. argentina) and attained a maximum value of 98% above preinfection levels by day 7. 2 Kininogen levels began falling on day 3 and reached minimum levels of 83% below preinfection levels on day 8. 3 Changes in both kinin and kininogen levels on day 3 coincided with the detection of low levels of parasites, and with a fall in packed cell volume. 4 Plasma kininase levels rose significantly 6 to 9 days after infection. Preparations of lysed and sonicated uninfected and infected red cells contained kininase activity, the respective red cell preparations being 23.9 and 11.4 times more active per mg protein than uninfected red cell preparations. The effect of pH, and the inhibitors disodium edetate, 1,10 phenanthroline and aprotinin on normal and infected plasma and on the various red cell preparations suggested that the rise in plasma kininase levels during infection was probably at least partly due to parasite products. SThese results are discussed in relation to previous data showing that both kallikrein activation and the onset of hypotension also occur on or about day 3.

Babesia divergens infections in the Mongolian gerbil: characteristics of a human strain

“…Malherbe (1956) and Maegraith et al (1957) described sludging of parasitized r.b.c.s in distended capillaries in many organs, which was a morphological aspect of the generalized shock from which the animals died. Since then several studies (Wright, 1977) have shown that vasoactive peptides (kinins) are produced in babesiosis resulting in vasodilatations and hypotensive shock. In contrast, some of the lesions in the hyperacute gerbil infection do not appear to be a consequence of vasodilatation and stagnant anoxia, but are suggestive of vasoconstriction.…”

“…In contrast, some of the lesions in the hyperacute gerbil infection do not appear to be a consequence of vasodilatation and stagnant anoxia, but are suggestive of vasoconstriction. As Wright has pointed out (Wright, 1975(Wright, , 1977, the systems of coagulation, kinin metabolism and endotoxin activity are all interlinked, and the final pathophysiological picture seen in the gerbil, and indeed in other babesioses, probably depends on the particular combination resulting from these mechanisms, in conjunction with the effects of anaemia, sympathetic activation and, possibly, toxic products of parasite origin.…”