Okadaic acid-sensitive protein phosphatases constrain phrenic long-term facilitation after sustained hypoxia
| Autor: | Jyoti J. Watters, Gordon S. Mitchell, Irawan Satriotomo, Tracy L. Baker-Herman, Julia E. R. Wilkerson |
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| Rok vydání: | 2008 |
| Předmět: |
Male
medicine.medical_specialty Phosphatase Long-Term Potentiation Methysergide Serine Rats Sprague-Dawley chemistry.chemical_compound Internal medicine Okadaic Acid medicine Phosphoprotein Phosphatases Animals Threonine Hypoxia General Neuroscience Intermittent hypoxia Okadaic acid Articles Hypoxia (medical) Motor neuron Rats Phrenic Nerve medicine.anatomical_structure Endocrinology chemistry Biochemistry medicine.symptom medicine.drug |
| Zdroj: | The Journal of neuroscience : the official journal of the Society for Neuroscience. 28(11) |
| ISSN: | 1529-2401 |
| Popis: | Phrenic long-term facilitation (pLTF) is a serotonin-dependent form of pattern-sensitive respiratory plasticity induced by intermittent hypoxia (IH), but not sustained hypoxia (SH). The mechanism(s) underlying pLTF pattern sensitivity are unknown. SH and IH may differentially regulate serine/threonine protein phosphatase activity, thereby inhibiting relevant protein phosphatases uniquely during IH and conferring pattern sensitivity to pLTF. We hypothesized that spinal protein phosphatase inhibition would relieve this braking action of protein phosphatases, thereby revealing pLTF after SH. Anesthetized rats received intrathecal (C4) okadaic acid (25 nm) before SH (25 min, 11% O2). Unlike (vehicle) control rats, SH induced a significant pLTF in okadaic acid-treated rats that was indistinguishable from rats exposed to IH (three 5 min episodes, 11% O2). IH and SH with okadaic acid may elicit pLTF by similar, serotonin-dependent mechanisms, because intravenous methysergide blocks pLTF in rats receiving IH or okadaic acid plus SH. Okadaic acid did not alter IH-induced pLTF. In summary, pattern sensitivity in pLTF may reflect differential regulation of okadaic acid-sensitive serine/threonine phosphatases; presumably, these phosphatases are less active during/after IH versus SH. The specific okadaic acid-sensitive phosphatase(s) constraining pLTF and their spatiotemporal dynamics during and/or after IH and SH remain to be determined. |
| Databáze: | OpenAIRE |
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