Phorbol ester contracts rabbit thoracic aorta by increasing intracellular calcium and by activating calcium influx.
The ability of the phorbol ester tumor promoter, PDB, to activate contraction and stimulate calcium influx was investigated in rabbit thoracic aorta. PDB caused a strong, slowly-developing sustained contraction in physiological salt solution which was concentration-related (0.01 to 10.0 microM). PDB-induced contractions (0.1 microM) in calcium-free medium were attenuated but not prevented. PDB (1.0 microM) maximally stimulated Ca influx above basal control, vehicle = 39.2 +/- 2.2; PDB 1.0 microM = 70.7 +/- 6.7 mumoles Ca/kg tissue; N = 16, p less than 0.01). These data suggest that PDB activates rabbit thoracic aorta by a combination of intracellular and extracellular calcium dependent mechanisms.
Gleason
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Flaim
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SF
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002118:Calcium / Q000502:physiology*; D005576:Colforsin / Q000494:pharmacology; D003593:Cytoplasm / Q000502:physiology; D005110:Extracellular Space / Q000502:physiology; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000502:physiology*; D009543:Nifedipine / Q000494:pharmacology; D015240:Phorbol 12,13-Dibutyrate; D010703:Phorbol Esters / Q000494:pharmacology*; D011224:Prazosin / Q000494:pharmacology; D011493:Protein Kinase C / Q000502:physiology; D011817:Rabbits; D013997:Time Factors
D010703:Phorbol Esters; D005576:Colforsin; D015240:Phorbol 12,13-Dibutyrate; D011493:Protein Kinase C; D009543:Nifedipine; D002118:Calcium; D011224:Prazosin