Determination of plasma kinin and kininogen levels in man

Abstract

SUMMARY1. A method for the estimation of free plasma kinin and kininogen is described, which is suitable for samples of blood taken in hospital.2. The method permits the assay of very low levels of kinin and substantially eliminates errors due to the presence of amines and other interfering substances.3. In normal subjects the mean value of free kinin is 2-8 ng (bradykinin equivalent)/ml. plasma, and 6-1,ug kininogen/ml.4. In vasovagal fainting, carcinoid flush, and dumping syndrome, during the phase of peripheral vasodilatation, the free kinin exceeds 10 ng/ml., and is often in excess of 30 ng/ml.5. Sudden release of free kinin is accompanied by a fall in kininogen level.

Plasma Kinin and Kininogen Levels in Women During Pregnancy and in Labour

“…It is upon the premise that all the kinin and its precursor were in the plasma (Brocklehurst & Zeitlin, 1967) that the calculation of plasma levels from the whole blood values using the haematocrit factor was carried out.…”

“…Approximately 25% of the kinin stores were found to be mobilized during labour and the authors calculated that 2 to 5 mg of kinin (as bradykinin) would be released in parturient blood during expulsion-enough to confer oxytocic activity on the plasma. However Brocklehurst & Zeitlin (1967) which 'fixes' the kinins at the moment of withdrawal of the blood specimen. This method relies on the estimation of whole blood kinin and kininogen levels, followed by calculation of the plasma levels using the haematocrit figure.…”

Reliable Evidence of Involvement of the Kinin System in Mouse Malaria

“…A half nil of blood was almost the total amount which could be collected from jugular vein of mice using this method. The volume of the venous blood was ejected into 15 ml of chilled 80% (v/v) ethanol in polyethylene tube and kinin was extracted according to the method reported by Brocklehurst and Zeitlin (9). The dried residues were stored at 20 C and dissolved in 0.5 ml of warn Munsick solution immediately before assay.…”

Plasma Kinin and Kininogen Levels in the Female Rat During the Oestrous Cycle, Pregnancy, Parturition and the Puerperium

“…The method used for the estimation of free kinin in the blood of the rat was that of Brocklehurst & Zeitlin (1967). The final dry extract was assayed on the rat isolated uterus preparation with synthetic bradykinin used as standard.…”