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Studies on the mechanism of action of the vasoconstrictive dihydropyridine, CGP 28392
- Source :
- European journal of pharmacology. 105(3-4)
- Publication Year :
- 1984
-
Abstract
- The effects of the vasoconstrictive dihydropyridine, CGP 29392, upon tension development and 45Ca2+ uptake by vascular smooth muscle were studied using isolated rabbit aorta. CGP 28392 did not elicit contractile responses when administered alone but lowered the threshold for the contractile response to elevated extracellular K+. CGP 28392 also increased the magnitude of the contractions elicited by submaximal concentrations of K+. This effect was competitively antagonized by PY 108-068, a Ca antagonist of the dihydropyridine class. Similarly, the relaxing effects of PY 108-068 upon KCl-constricted rabbit aorta were competitively antagonized by CGP 28392. The calcium content of unstimulated tissues was only minimally increased by CGP 28392 but the 45Ca2+ uptake stimulated by depolarizing levels of K+ was markedly augmented by this agent. Further analysis of the data indicated that CGP 28392 did not alter the relationship between tension development and 45Ca2+ uptake. In contrast, CGP 28392 was much less effective in augmenting the contractile response and 45Ca2+ uptake elicited by noradrenaline. These results thus support the hypothesis that CGP 28392 predominantly facilitates Ca2+ entry through potential-operated Ca2+ channels.
- Subjects :
- Male
medicine.medical_specialty
Vascular smooth muscle
Nifedipine
Pyridines
chemistry.chemical_element
Calcium
In Vitro Techniques
Potassium Chloride
Internal medicine
medicine
Animals
Vasoconstrictor Agents
Pharmacology
Dose-Response Relationship, Drug
Dihydropyridine
Antagonist
3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester
Calcium Channel Blockers
Endocrinology
Mechanism of action
chemistry
Vasoconstriction
Female
sense organs
Rabbits
medicine.symptom
medicine.drug
Muscle contraction
Subjects
Details
- ISSN :
- 00142999
- Volume :
- 105
- Issue :
- 3-4
- Database :
- OpenAIRE
- Journal :
- European journal of pharmacology
- Accession number :
- edsair.doi.dedup.....20db2a3eacd2c8e28055a88a136a8050