Modulation of calcitonin gene-related peptide release from dorsal thoraco-lumbar spinal cord slices by 5-HT3 receptors.
The release of endogenous calcitonin gene-related peptide-like immunoreactivity (CGRP-LI) from slices of dorsal and ventral thoraco-lumbar spinal cord was examined using a fixed volume incubation technique and radioimmunoassay. Incubation with potassium (25-100 mM) produced a dose-related increase in basal CGRP-LI in the supernatant of dorsal slices which was calcium dependent and release was also evoked by incubation with capsaicin (10 microM). Pre-incubation with the 5-HT3 agonist 2-methyl-5-hydroxytryptamine (10(-5) M) attenuated potassium-induced release from dorsal spinal cord slices, which was prevented by additional pre-incubation with the 5-HT3 antagonist ondansetron (10(-8) M). In contrast, the low level of CGRP-LI released from ventral spinal cord slices was not significantly enhanced by incubation with either potassium or capsaicin.
Scott
M A
MA
Department of Physiology and Pharmacology, Queen's Medical Centre, Nottingham University, UK.
Fone
K C
KC
D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism*; D002118:Calcium / Q000494:pharmacology; D002211:Capsaicin / Q000494:pharmacology; D066298:In Vitro Techniques; D017294:Ondansetron / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D011863:Radioimmunoassay; D011985:Receptors, Serotonin / Q000502:physiology*; D012701:Serotonin / Q000031:analogs & derivatives / Q000494:pharmacology; D012702:Serotonin Antagonists / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D013116:Spinal Cord / Q000187:drug effects / Q000378:metabolism*
D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; D012701:Serotonin; D017294:Ondansetron; C045918:2-methyl-5-HT; D015740:Calcitonin Gene-Related Peptide; D011188:Potassium; D002211:Capsaicin; D002118:Calcium