Biomaterial Database

Effect of phthalazinol (EG-626) on the mechanical activity and calcium influx of rabbit portal vein (1). 1977

M Kaiman, and S Shibata

Phthalazinol (EG-626), a newly synthesized cyclic AMP phosphodiesterase inhibitor, inhibited spontaneous phasic contractions (SPC) of isolated rabbit portal veins in a dose-dependent manner. Phthalazinol at a minimal concentration necessary to completely abolish the SPC did not alter 45Ca-uptake, 45Ca-influx, or the ED50S for methoxamine (me) and K+, but it did reduce the amplitude of the tonic contractions induced by ME and K+ by approximately 25%. On the other hand, verapamil, and La+3 abolished SPC, ME, and K+-induced contractions. Tetrodotoxin had no effect on SPC or on tonic contractions induced by ME and K+. Since extracellular Ca++ is known to be essential for SPC, ME, and K+-induced contractions in rabbit portal vein, the present results suggest that the abolishment of SPC and the partial inhibition of the ME and K+ responses by phthalazinol may be related to an action of this agent on intracellular Ca++ or Ca++-efflux.

UI	MeSH Term	Description	Entries
D007811	Lanthanum	The prototypical element in the rare earth family of metals. It has the atomic symbol La, atomic number 57, and atomic weight 138.91. Lanthanide ion is used in experimental biology as a calcium antagonist; lanthanum oxide improves the optical properties of glass.
D008297	Male		Males
D008729	Methoxamine	An alpha-1 adrenergic agonist that causes prolonged peripheral VASOCONSTRICTION.	Methoxamedrin,Methoxamine Hydrochloride,Metoxamine Wellcome,Vasoxin,Vasoxine,Vasoxyl,Vasylox,Hydrochloride, Methoxamine,Wellcome, Metoxamine
D009119	Muscle Contraction	A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.	Inotropism,Muscular Contraction,Contraction, Muscle,Contraction, Muscular,Contractions, Muscle,Contractions, Muscular,Inotropisms,Muscle Contractions,Muscular Contractions
D009130	Muscle, Smooth	Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)	Muscle, Involuntary,Smooth Muscle,Involuntary Muscle,Involuntary Muscles,Muscles, Involuntary,Muscles, Smooth,Smooth Muscles
D010793	Phthalazines	Bicyclic heterocyclic compounds containing a BENZENE ring fused to PYRIDAZINE.
D011188	Potassium	An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
D011724	Pyridazines	Six-membered rings with two adjacent nitrogen atoms also called 1,2-diazine.
D011817	Rabbits	A burrowing plant-eating mammal with hind limbs that are longer than its fore limbs. It belongs to the family Leporidae of the order Lagomorpha, and in contrast to hares, possesses 22 instead of 24 pairs of chromosomes.	Belgian Hare,New Zealand Rabbit,New Zealand Rabbits,New Zealand White Rabbit,Rabbit,Rabbit, Domestic,Chinchilla Rabbits,NZW Rabbits,New Zealand White Rabbits,Oryctolagus cuniculus,Chinchilla Rabbit,Domestic Rabbit,Domestic Rabbits,Hare, Belgian,NZW Rabbit,Rabbit, Chinchilla,Rabbit, NZW,Rabbit, New Zealand,Rabbits, Chinchilla,Rabbits, Domestic,Rabbits, NZW,Rabbits, New Zealand,Zealand Rabbit, New,Zealand Rabbits, New,cuniculus, Oryctolagus
D001769	Blood	The body fluid that circulates in the vascular system (BLOOD VESSELS). Whole blood includes PLASMA and BLOOD CELLS.