ABSTRACT
In the present investigation, we studied the influence of co-dergocrine mesylate (dihydroergotoxin mesylate) on platelet aggregation induced by adrenaline, adenosine diphosphate (ADP) and collagen in vitro. Platelet-rich plasma was incubated with increasing concentrations of co-dergocrine (1.5, 3.0, 6.0, 12.0, and 48.0 microng/ml). The lowest concentration of co-dergocrine tested (1.5 microng/ml) inhibited adrenaline-induced aggregation by 97%. Higher concentrations of the compound caused similar degress of inhibition. ADP-induced aggregation was only decreased significantly (20%, P < 0.001) by the highest concentration of co-dergocrine, whereas collagen-induced aggregation was not affected. Our results demonstrate that co-dergocrine selectively inhibits platelet aggregation triggered by adrenaline in vitro
Subject(s)
Humans , Adenosine Diphosphate/antagonists & inhibitors , Platelet Aggregation/physiology , Collagen/antagonists & inhibitors , Dihydroergotoxine/pharmacology , Epinephrine/antagonists & inhibitors , In Vitro TechniquesABSTRACT
The influence of an aqueous/ethanolic extract of M. velutina (CE) and of two compound (MV 8608 and MV 8612) purified from the plant on BK-, Ad- and K+ -induced responses of the rat duodenum was analyzed in vitro. In preparations precontracted with Ca2+, the CE (1 and 2 mg/ml) markedly inhibited BK -induced relaxation in a dose-dependent manner but was less effective against Ad-induced relaxation. The CE (0.5 mg/ml) also antagonized BK -induced relaxation and contraction of strips bathed in normal medium. The two compounds from M. velutina (10 and 20 microng/ml) also promoted a dose-dependent blockade of both responses to BK, only slightly depressing the response to K+
Subject(s)
Rats , Animals , Male , Female , Bradykinin/antagonists & inhibitors , Duodenum/drug effects , Epinephrine/antagonists & inhibitors , Plant Extracts/pharmacology , Plants, Medicinal , Muscle ContractionABSTRACT
All the Krebs metabolites except pyruvate, lactate, acetate and succinate reduced the force and rate of myocardial contractions and also decreased cardiac output in frog. Succinate on the contrary was found to augment the rate and force of heart. The cardiac stimulation produced by epinephrine was reduced by fumarate, malate, oxaloacetate and alpha-oxoglutarate, whereas transaconitate and citrate produced only a slight inhibition. Pyruvate, lactate, acetate and succinate did not alter cardiac response to epinephrine.
Subject(s)
Animals , Anura , Cardiac Output/drug effects , Epinephrine/antagonists & inhibitors , Heart/drug effects , Heart Rate/drug effects , Myocardial Contraction/drug effects , Ranidae , Tricarboxylic Acids/pharmacologyABSTRACT
Two basic anilides EA-7 and EA-8 were investigated for their antispasmodic activity against a variety of spasmogens on different tissues from different species of animals and comparison was made with lignocaine. EA-8 was found to be the most potent in this respect, followed by EA-7 and lignocaine. The antispasmodic potency does not correspond to their local anaesthetic potency. This suggests a direct depressant effect on tissues.