TLC Characterization of Liposomes Containing Angiotensinogen, Angiotensine I, Angiotensine II and Saralazin

Brǎiloiu, Eugen; Todiras, Mihail; Margineanu, Anca; Costuleanu, Marcel; Brailoiu, Cristina; Filipeanu, Catalin M.; Costuleanu, Angela; Rusu, Valeriu; Petrescu, G

doi:10.1002/(sici)1099-0801(199705)11:3<160::aid-bmc661>3.0.co;2-t

Cited by 4 publications

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References 14 publications

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“…We previously demonstrated the effective use of liposomes to study intracellular effects of various compounds in rat aorta ( Brailoiu et al ., 1993 ; 1995 ; Filipeanu et al ., 1998a ). Integrity of angiotensin containing liposomes is maintained for concentrations less than 10 −5 M Ang I and 10 −4 M Ang II, respectively ( Brailoiu et al ., 1997 ).…”

Section: Discussionmentioning

confidence: 99%

Contractile effects by intracellular angiotensin II via receptors with a distinct pharmacological profile in rat aorta

Brǎiloiu

Filipeanu

Tica

et al. 1999

British J Pharmacology

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1 We studied the eect of intracellular angiotensin II (Ang II) and related peptides on rat aortic contraction, whether this eect is pharmacologically distinguishable from that induced by extracellular stimulation, and determined the Ca 2+ source involved. 2 Compounds were delivered into the cytoplasm of de-endothelized aorta rings using multilamellar liposomes. Contractions were normalized to the maximum obtained with phenylephrine (10 75 M).3 Intracellular administration of Ang II (incorporation range: 0.01 ± 300 nmol mg 71

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Section: Discussionmentioning

confidence: 99%

Contractile effects by intracellular angiotensin II via receptors with a distinct pharmacological profile in rat aorta

Brǎiloiu

Filipeanu

Tica

et al. 1999

British J Pharmacology

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Characterization of dynamically prepared phospholipid-modified reversed-phase columns

Tsirkin

Grushka

2001

Journal of Chromatography A

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Contractile effects of angiotensin peptides in rat aorta are differentially dependent on tyrosine kinase activity

Petrescu

Costuleanu²,

Slătineanu³

et al. 2001

J Renin Angiotensin Aldosterone Syst

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It has been suggested that tyrosine kinase activity participates in the regulation of signal transduction associated with angiotensin II (Ang II)-induced pharmaco-mechanical coupling in rat aortic smooth muscle. We further tested the effects of genistein, a tyrosine-kinase inhibitor, and its inactive analogue, daidzein, on angiotensin I (Ang I), angiotensin III (Ang III) and angiotensin IV (Ang IV) contractions, as compared with those on Ang II. Genistein partially inhibited Ang II- and Ang I-induced contractions. The genistein-induced inhibition was more evident on Ang III and especially important on Ang IV contractile effects. Thus, Ang IV- and Ang III-induced contractions seem to be more dependent on tyrosine kinase activity than those evoked by Ang II or Ang I. Daidzein did not significantly affect the contractile effects of any of angiotensin peptides tested. These results clearly suggest that the inhibition of the action of angiotensin peptides actions by genistein is mediated by inhibition of endogenous tyrosine kinase activity. Furthermore, our data show that the type and/or intensity of tyrosine kinase activity is differentially associated with the contractile effects of different angiotensin peptides in rat aorta. Nifedipine, a blocker of membrane L-type Ca2+ channels, strongly inhibited Ang IV-induced contractions. At the same time, it significantly inhibited Ang III contractile effects as compared with Ang II and Ang I contractions. Meanwhile, we observed a close relationship between calcium influx and tyrosine kinase phosphorylation activity under the stimulatory effects of angiotensin peptides. Furthermore, genistein did not significantly influence the phasic contractions induced by angiotensin peptides in Ca2+-free Krebs-Henseleit solution. Thus, it appears that Ca2+ influx, rather than the release of Ca2+ from IP3-sensitive stores, may play a major role in the contractile effects of angiotensin peptides in rat aorta via tyrosine kinase activation. One argument against a direct action of genistein on the Ca2+ channel itself is that it did not markedly affect the K+-induced contraction (depolarisation) in rat aorta. At the same time, a potential role for tyrosine kinase activity in the process of calcium entry is suggested. An elevation of intracellular calcium via tyrosine kinase-mediated processes may mediate the actions of G-protein coupled receptor agonists in smooth muscle, including angiotensin peptides.

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TLC Characterization of Liposomes Containing Angiotensinogen, Angiotensine I, Angiotensine II and Saralazin

Cited by 4 publications

References 14 publications

Contractile effects by intracellular angiotensin II via receptors with a distinct pharmacological profile in rat aorta

Contractile effects by intracellular angiotensin II via receptors with a distinct pharmacological profile in rat aorta

Characterization of dynamically prepared phospholipid-modified reversed-phase columns

Contractile effects of angiotensin peptides in rat aorta are differentially dependent on tyrosine kinase activity

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