A 23187-stimulated calcium uptake and GABA release by cerebrocortical synaptosomes: effects of high pressure.
Guinea pig cerebrocortical synaptosome preparations were used to study the effect of compression to 62 ATA on 45Ca2+ uptake and [3H]GABA release using a calcium ionophore A 23187, which bypasses the voltage-sensitive calcium channel. Pressure was found to exert a suppressive effect on the A 23187-induced release of [3H]GABA, while having no significant effect on A 23187-stimulated 45Ca2+ uptake. On the other hand, both depolarization-induced 45Ca2+ uptake and [3H]GABA release were inhibited by pressure exposure. These results suggest that pressure may suppress GABA release by affecting pre-synaptic events subsequent to calcium influx.
Gilman
S C
SC
Diving Medicine Department, Naval Medical Research Institute, Bethesda, Md.
Colton
J S
JS
Grossman
Y
Y
D000818:Animals; D001274:Atmospheric Pressure; D000001:Calcimycin / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D002132:Calcium Radioisotopes; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism*; D006168:Guinea Pigs; D006610:High Pressure Neurological Syndrome / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D009411:Nerve Endings / Q000187:drug effects; D011188:Potassium / Q000494:pharmacology; D013569:Synapses / Q000187:drug effects / Q000502:physiology; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D002132:Calcium Radioisotopes; D000001:Calcimycin; D005680:gamma-Aminobutyric Acid; D011188:Potassium; D002118:Calcium