Precursors and metabolites of norepinephrine in sympathetic ganglia of the dog
| Autor: | Gertrude M. Tyce, Sharon L. Chinnow, Ramona S. Montreuil, Eric W. Kristensen |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
medicine.medical_specialty
Catechols Stimulus (physiology) Biochemistry Methylation Cellular and Molecular Neuroscience chemistry.chemical_compound Norepinephrine Catecholamines Dogs Dopamine Internal medicine medicine Oxotremorine Animals Amphetamine Neurotransmitter Ganglia Sympathetic Chemistry Sulfates Phenylethanolamine N-Methyltransferase Osmolar Concentration Stimulation Chemical Perfusion medicine.anatomical_structure Endocrinology Epinephrine Peripheral nervous system Catecholamine medicine.drug |
| Zdroj: | Journal of neurochemistry. 54(5) |
| ISSN: | 0022-3042 |
| Popis: | 3,4-Dihydroxyphenylalanine, dopamine, epinephrine, 3,4-dihydroxyphenylglycol, and 3,4-dihydroxyphenylacetic acid as well as norepinephrine were measured in dog lumbar sympathetic ganglia. The responses of these compounds to several classes of stimuli were investigated using an isolated time-resolved superfusion system. Nonselective (i.e., amphetamine and high K+) and receptor-mediated selective (oxotremorine) stimuli were used to evoke releases. The overflows of all compounds were measured by HPLC with electrochemical detection. The efficiency of each stimulus was estimated by normalizing the amount of evoked release to the total neurotransmitter pool when the stimulus was applied; i.e., fractional release was calculated. Overflows of all compounds except 3,4-dihydroxyphenylalanine were enhanced by a 10-min 100 microM amphetamine stimulus, and each of the catecholamine pools (dopamine, norepinephrine, and epinephrine) was affected to the same degree. By contrast, the 3,4-dihydroxyphenylalanine and dopamine pools were more readily releasable than the norepinephrine pool with a 10-min 80 mM K+ stimulus, and these releases were Ca2+ dependent. Epinephrine was released in preference to norepinephrine by a 10-min 1 mM oxotremorine stimulus. The data suggest the existence of at least three types of neurons in dog lumbar ganglia and are consistent with previous histological observations. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text