scholarly journals The Combined Inotropic and Vasorelaxant Effect of DHQ-11, A Conjugate of Flavonoid Dihydroquercetin with Isoquinoline Alkaloid 1-Aryl-6,7-Dimethoxy-1,2.3,4-Tetrahydroisoquinoline.

2021 ◽  
Vol 14 (02) ◽  
pp. 651-661
Author(s):  
Pulat B. Usmanov ◽  
Inoyat Z. Jumayev ◽  
Shavkat Yu. Rustamov ◽  
Abdisalim A. Zaripov ◽  
Adilbay T. Esimbetov ◽  
...  

This study investigated the positive inotropic andvasorelaxant activity ofDHQ-11, aconjugate of flavonoid dihydroquercetin with isoquinoline alkaloid 1-aryl-6,7-dimethoxy-1,2.3,4-tetrahydroisoquinoline.A study was performed using anterior papillary muscle removed from the left ventricle and thoracic aorta dissected from rats. DHQ-11 produceda concentration-dependent positive inotropic effect which was more potent than their parent compounds alone. The positive inotropic effect of conjugate DHQ-11was significantly attenuated by the β-adrenoreceptor inhibitor propranolol and L-type Ca2+ channel blocker nifedipine. Also,conjugate DHQ-11 markedly potentiated first post-rest responses indicating that it can modulate Ca2+ loading/release processes in the sarcoplasmic reticulum.These results suggest that positive inotropic effect produced by conjugate DHQ-11may be mediated through activation oftheβ-AR/AC/cAMP/PKA pathway that leads to increased Ca2+ influx and rises in Ca2+ loading/release in the SR, resulting in increased [Ca2+]i and enhanced contraction force. DHQ-11 significantly relaxed both high KCl- and phenylephrine-induced contractions of rat aortic rings whichwere significantly inhibited by lowering extracellular Ca2+ concentration and in the presence of verapamil.DHQ-11 significantly inhibited phenylephrine-induced contractions in a Ca2+-free medium, in the presence of verapamil. The vasorelaxant effect of the DHQ-11 was significantly reduced by the removal of endothelium and in the presenceof L-NAME and methylene blue as well as glibenclamide and TEA.These results suggest that the vasorelaxation produced by conjugate DHQ-11may be mediatedbyan endothelium-independent mechanism involving activation of KATP and BKCa channels and inhibition of L-type VDCCs and Ca2+ release from the sarcoplasmic reticulum and endothelium-dependent mechanism through activation of the NO/sGC/cGMP/PKG signaling pathway resulting in a decrease of intracellular Ca2+levels. These observations reveal that the conjugate DHQ-11 due to its high positive inotropic and vasorelaxant activity could be a promising compound for the design and development of new drugs for the treatment of heart failure.

2021 ◽  
Vol 3 (3) ◽  
pp. 01-04
Author(s):  
Shavkat Yu. Rustamov ◽  
Inoyat Z. Jumayev ◽  
Sadriddin N. Boboev ◽  
Eldor B. Ibragimov ◽  
Pulat B. Usmanov ◽  
...  

This study evaluated the mechanism of inotropic effect of an isoquinoline alkaloid derivative, 1-(2´-bromine-4´,5´-dimethoxyphenyl)-6,7-dimethoxy-1,2,3,4- tetrahydroisoquinoline (F-18) using electrically stimulated rat left ventricular papillary muscle of rat. The F-18 alkaloid have been shown to have positive inotropic effect on papillary muscle contraction activity, IC50 value -14,6 µM. Са2+L-channel blocker - nifedipine was used in experiments. Inotropic effects of F-18 isoquinoline alkaloid on cardiomyocytes were suggested, based on results obtained in experiments carried in cardiomyocytes SR Ca2+- transport systems modulation.


Author(s):  
El-Ouady Fadwa ◽  
Mohamed Eddouks

Aims: The aim of the study was to investigate experimentally the antihypertensive effect of Ruta Montana. Background: Ruta montana L. is traditionally used in Moroccan herbal medicine to treat hypertension. This study aimed to evaluate experimentally the hypotensive and vasoactive properties of this plant. Objective: The objective of the study was to evaluate the effect of the aqueous extract of Ruta Montana on blood pressure parameters in LNAME-induced hypertensive rats and to determine the vasorelaxant activity of this aqueous extract. Methods: The antihypertensive effect of the aqueous extract obtained from Ruta montana aerial parts (RMAPAE) (200 mg/kg) was evaluated in normal and anesthetized hypertensive rats. Blood pressure parameters (systolic blood pressure (SBP), mean blood pressure (MBP) and diastolic blood pressure (DBP)) and heart rate were measured using a tail-cuff and a computer-assisted monitoring device. The acute and chronic effect of RMAPAE was recorded during 6 hours for the acute experiment and during 7 days for the sub-chronic test. In the other set, the vasorelaxant effect of RMAPAE on the contractile response was undertaken in isolated thoracic aorta. Results: The results indicated that RMAPAE extract significantly decreased SBP, MBP, DBP and heart rate in L-NAMEinduced hypertensive rats. Furthermore, RMAPAE was demonstrated to induce a dose dependent relaxation in the aorta precontracted with Epinephrine or KCl. More interestingly, this vasorelaxant activity of RMAPAE seems to be probably mediated through the prostaglandins pathway. Conclusion: The present study illustrates the beneficial action of Ruta montana on hypertension and supports then its use as an antihypertensive agent.


Circulation ◽  
2003 ◽  
Vol 108 (13) ◽  
pp. 1633-1639 ◽  
Author(s):  
Rui-Ping Xiao ◽  
Sheng-Jun Zhang ◽  
Khalid Chakir ◽  
Pavel Avdonin ◽  
Weizhong Zhu ◽  
...  

1988 ◽  
Vol 254 (2) ◽  
pp. G201-G209 ◽  
Author(s):  
C. B. Koelbel ◽  
G. van Deventer ◽  
S. Khawaja ◽  
M. Mogard ◽  
J. H. Walsh ◽  
...  

Somatostatin has been shown to inhibit antral motility in vivo. To examine the effect of somatostatin on cholinergic neurotransmission in the canine antrum, we studied the mechanical response of and the release of [3H]acetylcholine from canine longitudinal antral muscle in response to substance P, gastrin 17, and electrical stimulation. In unstimulated tissues, somatostatin had a positive inotropic effect on spontaneous phasic contractions. In tissues stimulated with substance P and gastrin 17, but not with electrical stimulation, somatostatin inhibited the phasic inotropic response dose dependently. This inhibitory effect was abolished by indomethacin. Somatostatin stimulated the release of prostaglandin E2 radioimmunoreactivity, and prostaglandin E2 inhibited the release of [3H]acetylcholine induced by substance P and electrical stimulation. Somatostatin increased the release of [3H]acetylcholine from unstimulated tissues by a tetrodotoxin-sensitive mechanism but inhibited the release induced by substance P and electrical stimulation. These results suggest that somatostatin has a dual modulatory effect on cholinergic neurotransmission in canine longitudinal antral muscle. This effect is excitatory in unstimulated tissues and inhibitory in stimulated tissues. The inhibitory effect is partially mediated by prostaglandins.


Sign in / Sign up

Export Citation Format

Share Document