A BRADYKININ-POTENTIATING FRACTION ISOLATED FROM THE VENOM OF EGYPTIAN SCORPION BUTHUS-OCCITANUS INDUCED PROSTAGLANDIN BIOSYNTHESIS IN FEMALE GUINEA-PIGS
Arma. Meki et He. Omar, A BRADYKININ-POTENTIATING FRACTION ISOLATED FROM THE VENOM OF EGYPTIAN SCORPION BUTHUS-OCCITANUS INDUCED PROSTAGLANDIN BIOSYNTHESIS IN FEMALE GUINEA-PIGS, Comparative biochemistry and physiology. Part C, Pharmacology toxicology & endocrinology, 116(3), 1997, pp. 183-189
A fraction with bradykinin potentiating activity was chemically isolat
ed from the Venom of the Egyptian scorpion Buthus occitanus. The pharm
acological activity of the fraction (BPF) was bioassayed by its abilit
y to potentiate added bradykinin on the isolated guinea pig ileum as w
ell as its inhibitory activity on angiotensin converting enzyme. The m
ode of action of this fraction on gonads of immature female guinea pig
s was studied. The fraction was i.p. injected I mu g/g body weight for
five times in animals (about, 150 g) at successive time intervals of
I days each. Total body, ovarian, and uterine tissue weights were sign
ificantly increased as well as uterine total protein, RNA and cyclic n
ucleotides contents. Concomitantly, PGF(2 alpha) level showed signific
ant elevation in both uterine and ovarian tissues. The uterine tissue
homogenates in vitro showed an enhancing effect in response to the add
ed fraction (1 mu g/ml) and bradykinin (I mu g/ml) fbr prostaglandin b
iosynthesis from radiolabelled precursor C-14-linoleic acid into its l
abelled metabolites: arachidonic acid, PGD(2), TxB(2), PGE(2), PGF(2 a
lpha), and 6-keto PGF(1 alpha). This enhancement effect was abolished
in the presence of BK inhibitor but the labelled PGF(2 alpha) was stil
l high, The results clearly indicate that the increase of PGs resultin
g from both in vivo and in vitro experiments may contribute to the inh
ibition of ACE and potentiation of exogenous and endogenous BK. (C) 19
97 Elsevier Science Inc.