Effects of pentobarbitone on 45Ca2+ transport by rat brain mitochondria.
The effects of pentobarbitone on the transport of 45Ca2+ by rat brain mitochondria were studied, using the Ruthenium Red-EGTA quench technique. In the presence of succinate and inorganic phosphate, mitochondria rapidly accumulate 45Ca2+. Pentobarbitone (0.1-1.0 mM) stimulates the initial rate of Ca2+ transport. In contrast, pentobarbitone (1 mM) did not affect the NaCl (50 mM)-induced efflux of 45Ca2+ from mitochondria. Dibucaine (60 micro M), a clinically used local anaesthetic, inhibits both 45Ca2+ uptake an efflux. The results suggest that barbiturate stimulation of mitochondrial Ca2+ uptake may, in combination with effects on other Ca2+ sequestering processes, contribute to the inhibitor of transmitter release observed at a number of synapses.
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D001921:Brain / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D003992:Dibucaine / Q000494:pharmacology; D007700:Kinetics; D008297:Male; D008928:Mitochondria / Q000378:metabolism*; D010424:Pentobarbital / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012430:Ruthenium Red; D012965:Sodium Chloride / Q000494:pharmacology
D012430:Ruthenium Red; D012965:Sodium Chloride; D010424:Pentobarbital; D003992:Dibucaine; D002118:Calcium