Biomaterial Database

Calcium antagonist-induced relaxation of the prostaglandin-F2 alpha response of isolated calf retinal resistance arteries. 1989

P J Nielsen, and N C Nyborg

Department of Pharmacology, University of Aarhus, Denmark.

The relaxing effect of nitrendipine and D600 on isolated ring segments of calf retinal resistance arteries (i.d. ca. 200 microns) contracted with prostaglandin-F2 alpha (PGF2 alpha) or high potassium solution was studied. The vessel response to both PGF2 alpha and potassium stimulation was dependent on extracellular calcium. Removal of extracellular calcium reduced the vessel response to PGF2 alpha and potassium by 85% and 98%, respectively (P less than 0.01). Both calcium antagonists induced a concentration dependent relaxation of PGF2 alpha pre-contracted vessels with = -log[IC50(M)]-values of 8.01 and 7.13 for nitrendipine and D600 (P less than 0.05), respectively. The calcium antagonists were equieffective in relaxing the vessels amounting to 33% for nitrendipine at 10(-6) M and 37% for D600 at 10(-5) M. Further analysis of the data revealed that the nitrendipine induced relaxation of the PGF2 alpha response was linearly correlated with the internal lumen diameter of the vessels. No correlation was found for the D600 induced relaxation. At the highest concentrations of nitrendipine, 10(-6) M, and D600, 10(-5) M, the potassium induced response was reduced by 94 and 75%, respectively. The results show that calcium antagonists only partially relax retinal resistance arteries contracted with PGF2 alpha although the vessels are dependent on extracellular calcium for active force generation. Calcium must therefore be activated by PGF2 alpha through other pathways than those blocked by calcium antagonists.

UI	MeSH Term	Description	Entries
D009126	Muscle Relaxation	That phase of a muscle twitch during which a muscle returns to a resting position.	Muscle Relaxations,Relaxation, Muscle,Relaxations, Muscle
D009568	Nitrendipine	A calcium channel blocker with marked vasodilator action. It is an effective antihypertensive agent and differs from other calcium channel blockers in that it does not reduce glomerular filtration rate and is mildly natriuretic, rather than sodium retentive.	Balminil,Bay e 5009,Bayotensin,Baypresol,Baypress,Gericin,Jutapress,Nidrel,Niprina,Nitre AbZ,Nitre-Puren,Nitregamma,Nitren 1A Pharma,Nitren Lich,Nitren acis,Nitrend KSK,Nitrendepat,Nitrendi Biochemie,Nitrendidoc,Nitrendimerck,Nitrendipin AL,Nitrendipin Apogepha,Nitrendipin Atid,Nitrendipin Basics,Nitrendipin Heumann,Nitrendipin Jenapharm,Nitrendipin Lindo,Nitrendipin Stada,Nitrendipin beta,Nitrendipin-ratiopharm,Nitrendipino Bayvit,Nitrendipino Ratiopharm,Nitrensal,Nitrepress,Tensogradal,Trendinol,Vastensium,nitrendipin von ct,nitrendipin-corax,Nitre Puren,NitrePuren,Nitrendipin ratiopharm,Nitrendipinratiopharm,nitrendipin corax,nitrendipincorax
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.
D012161	Retinal Artery	Central retinal artery and its branches. It arises from the ophthalmic artery, pierces the optic nerve and runs through its center, enters the eye through the porus opticus and branches to supply the retina.	Central Retinal Artery,Arteries, Central Retinal,Arteries, Retinal,Artery, Central Retinal,Artery, Retinal,Central Retinal Arteries,Retinal Arteries,Retinal Arteries, Central,Retinal Artery, Central
D002417	Cattle	Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.	Beef Cow,Bos grunniens,Bos indicus,Bos indicus Cattle,Bos taurus,Cow,Cow, Domestic,Dairy Cow,Holstein Cow,Indicine Cattle,Taurine Cattle,Taurus Cattle,Yak,Zebu,Beef Cows,Bos indicus Cattles,Cattle, Bos indicus,Cattle, Indicine,Cattle, Taurine,Cattle, Taurus,Cattles, Bos indicus,Cattles, Indicine,Cattles, Taurine,Cattles, Taurus,Cow, Beef,Cow, Dairy,Cow, Holstein,Cows,Dairy Cows,Domestic Cow,Domestic Cows,Indicine Cattles,Taurine Cattles,Taurus Cattles,Yaks,Zebus
D005711	Gallopamil	Coronary vasodilator that is an analog of iproveratril (VERAPAMIL) with one more methoxy group on the benzene ring.	Methoxyverapamil,D-600,D600,Elgiprona,Gallobeta,Gallopamil Hydrochloride,Prebet,Procorum,gallopamil von ct,D 600,Hydrochloride, Gallopamil
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
D015237	Dinoprost	A naturally occurring prostaglandin that has oxytocic, luteolytic, and abortifacient activities. Due to its vasocontractile properties, the compound has a variety of other biological actions.	PGF2,PGF2alpha,Prostaglandin F2,Prostaglandin F2alpha,9alpha,11beta-PGF2,Enzaprost F,Estrofan,PGF2 alpha,Prostaglandin F2 alpha,9alpha,11beta PGF2,F2 alpha, Prostaglandin,F2alpha, Prostaglandin,alpha, PGF2