The neurosteroids pregnenolone and pregnenolone-sulfate but not progesterone, block Ca2+ currents in acutely isolated hippocampal CA1 neurons
| Autor: | K. T. Spence, J.M.H. ffrench-Mullen, C. R. Plata-Salaman |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
medicine.medical_specialty
Neuroactive steroid Guinea Pigs chemistry.chemical_element Calcium Hippocampus General Biochemistry Genetics and Molecular Biology Membrane Potentials chemistry.chemical_compound Internal medicine medicine Animals Picrotoxin Patch clamp General Pharmacology Toxicology and Pharmaceutics Cells Cultured Progesterone Neurons Dose-Response Relationship Drug Voltage-dependent calcium channel GABAA receptor General Medicine Kinetics Endocrinology chemistry Pregnenolone Calcium Channels Pregnenolone sulfate medicine.drug |
| Zdroj: | Life Sciences. 49:PL235-PL239 |
| ISSN: | 0024-3205 |
| Popis: | The neurosteroids pregnenolone (PE) and pregnenolone-sulfate (PS) have been shown to interact with the GABAA receptor in the central nervous system. In contrast, nothing is known of any possible modulation of voltage-gated calcium channels (VGCC). We have examined the interaction of PE, PS and progesterone on VGCC in acutely isolated adult guinea-pig hippocampal CA1 neurons using the whole-cell patch clamp technique. PE and PS depressed the calcium current at low micromolar concentrations (0.001-100 microM). The time to peak of the calcium current was slowed by PE and PS. The blocking action of PE and PS occurs in the presence of 10 microM picrotoxin. In contrast, progesterone had no effect on the Ca2+ current, indicating specificity for PE and PS. These results demonstrate a direct and novel membrane site of action for PE and PS, suggesting a possible role influencing brain excitability. |
| Databáze: | OpenAIRE |
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