Hypertension, Vol 6, 255-261, Copyright © 1984 by American Heart Association
ML Reis, WD de Jesus, LM Bertramini-Sabbag, EM Krieger and LJ Greene
The present study was undertaken to evaluate the participation of the
kallikrein-kinin system in the normalization of blood pressure after
release of the clip in one-kidney, one clip hypertensive rats ( 1K1C ).
Kininogen was determined before and after unclipping by tryptic digestion
of denatured rat plasma, and spasmogenic activity was measured with
isolated guinea pig ileum. In contrast to human plasma for which bradykinin
(BK) is the only trypsin-releasable spasmogenic substance ( TRSS ), rat
plasma contains non-BK TRSS (Fractions P1 and P2) as well as BK. Fractions
P1 and P2 were separated from BK by SP- Sephadex chromatography. An
increase of total TRSS was demonstrated 60 days after clipping and reached
a maximum at approximately Day 75, which was two times that of the
normotensive controls (NC). The level of total TRSS did not change after
unclipping . The increased level of TRSS in the hypertensive state
confirmed the observations of other investigators who reported increased
kininogen levels but who could not distinguish between BK and non-BK TRSS
because bioassays were performed without prior chromatographic separation
of the spasmogenic activities. Fractions P1 and P2 were present in the TRSS
of both 1K1C and NC plasma, but were two to six times higher in 1K1C and
thus probably accounted quantitatively for the increased TRSS in 1K1C . The
data suggest that in the hypertensive state there is an alteration in the
relative amounts of some plasma proteins that contain non-BK TRSS within
their amino acid sequences. Fractions P1 and P2 also contain potentiating
peptides and have not yet been purified to homogeneity.(ABSTRACT TRUNCATED
AT 250 WORDS)
ARTICLES
Increased levels of new spasmogenic substances released by trypsin from plasma of hypertensive rats