Biomaterial Database

Evidence for two types of P2-purinoceptor in longitudinal muscle of the rabbit portal vein. 1985

C Kennedy, and G Burnstock

The actions of ATP, 2-methylthioATP, alpha, beta-methyleneATP, beta, gamma-methyleneATP, adenosine and non-adrenergic, non-cholinergic inhibitory nerve stimulation were compared on the ergotamine-contracted longitudinal muscle of the isolated rabbit portal vein with the vessel endothelium either intact or removed by mechanical rubbing. Non-adrenergic, non-cholinergic inhibitory nerve stimulation produced frequency-dependent relaxations. The purines (except alpha, beta-methyleneATP) also caused relaxation with the following potency order: 2-methylthioATP greater than ATP greater than beta, gamma-methyleneATP = adenosine. 8-Phenyltheophylline, a potent P1-purinoceptor antagonist, antagonised relaxations to adenosine but not those to ATP indicating that ATP and its analogues act directly via a P2-purinoceptor and not via a P1-purinoceptor after breakdown to adenosine. alpha, beta-MethyleneATP produced contractions which were not maintained and was tachyphylactic. The contractions were unaffected by tetrodotoxin and therefore unlikely to be due to release of a contractile substance from a neuronal source following initiation of an action potential. Removal of the endothelium did not affect the actions of non-adrenergic, non-cholinergic inhibitory nerve stimulation, ATP, alpha, beta-methyleneATP, beta, gamma-methyleneATP or adenosine. Thus purine action does not have an endothelium-dependent component in the rabbit portal vein longitudinal muscle. The results indicate the possibility that there may be more than one type of P2-purinoceptor in this tissue.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009126	Muscle Relaxation	That phase of a muscle twitch during which a muscle returns to a resting position.	Muscle Relaxations,Relaxation, Muscle,Relaxations, Muscle
D009131	Muscle, Smooth, Vascular	The nonstriated involuntary muscle tissue of blood vessels.	Vascular Smooth Muscle,Muscle, Vascular Smooth,Muscles, Vascular Smooth,Smooth Muscle, Vascular,Smooth Muscles, Vascular,Vascular Smooth Muscles
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
D011983	Receptors, Purinergic	Cell surface proteins that bind PURINES with high affinity and trigger intracellular changes which influence the behavior of cells. The best characterized classes of purinergic receptors in mammals are the P1 receptors, which prefer ADENOSINE, and the P2 receptors, which prefer ATP or ADP.	Methyladenine Receptors,Purine Receptors,Purinergic Receptor,Purinergic Receptors,Purinoceptors,Purine Receptor,Purinoceptor,Receptors, Methyladenine,Receptors, Purine,Receptor, Purine,Receptor, Purinergic
D004727	Endothelium	A layer of epithelium that lines the heart, blood vessels (ENDOTHELIUM, VASCULAR), lymph vessels (ENDOTHELIUM, LYMPHATIC), and the serous cavities of the body.	Endotheliums
D000255	Adenosine Triphosphate	An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.	ATP,Adenosine Triphosphate, Calcium Salt,Adenosine Triphosphate, Chromium Salt,Adenosine Triphosphate, Magnesium Salt,Adenosine Triphosphate, Manganese Salt,Adenylpyrophosphate,CaATP,CrATP,Manganese Adenosine Triphosphate,MgATP,MnATP,ATP-MgCl2,Adenosine Triphosphate, Chromium Ammonium Salt,Adenosine Triphosphate, Magnesium Chloride,Atriphos,Chromium Adenosine Triphosphate,Cr(H2O)4 ATP,Magnesium Adenosine Triphosphate,Striadyne,ATP MgCl2
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013329	Structure-Activity Relationship	The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.	Relationship, Structure-Activity,Relationships, Structure-Activity,Structure Activity Relationship,Structure-Activity Relationships
D017981	Receptors, Neurotransmitter	Cell surface receptors that bind signalling molecules released by neurons and convert these signals into intracellular changes influencing the behavior of cells. Neurotransmitter is used here in its most general sense, including not only messengers that act to regulate ion channels, but also those which act on second messenger systems and those which may act at a distance from their release sites. Included are receptors for neuromodulators, neuroregulators, neuromediators, and neurohumors, whether or not located at synapses.	Neurohumor Receptors,Neuromediator Receptors,Neuromodulator Receptors,Neuroregulator Receptors,Receptors, Neurohumor,Receptors, Synaptic,Synaptic Receptor,Synaptic Receptors,Neuromediator Receptor,Neuromodulator Receptor,Neuroregulator Receptor,Neurotransmitter Receptor,Receptors, Neuromediators,Receptors, Neuromodulators,Receptors, Neuroregulators,Receptors, Neurotransmitters,Neuromediators Receptors,Neuromodulators Receptors,Neuroregulators Receptors,Neurotransmitter Receptors,Neurotransmitters Receptors,Receptor, Neuromediator,Receptor, Neuromodulator,Receptor, Neuroregulator,Receptor, Neurotransmitter,Receptor, Synaptic,Receptors, Neuromediator,Receptors, Neuromodulator,Receptors, Neuroregulator