Adrenoceptor-activated nitric oxide synthesis in salivary acinar cells.
Adv Dent Res
; 14: 62-8, 2000 Dec.
Article
em En
| MEDLINE
| ID: mdl-11842926
ABSTRACT
We investigated the cellular regulation of nitric oxide synthase (NOS) activity in isolated acinar cells from rat parotid and human labial salivary glands, using the newly developed fluorescent nitric oxide (NO) indicator, DAF-2. We found that sympathetic stimulation with norepinephrine (NE) caused a strong increase in NO synthesis that was not seen after parasympathetic stimulation with acetylcholine. In rat parotid acinar cells, we furthermore investigated to which extent the NOS activity was dependent on the intracellular free Ca2+ concentration ([Ca2+]i) by simultaneously measuring NO synthesis and [Ca2+]i. It was found that a simple correlation between the rise in [Ca2+]i and the rate of NO production following NE stimulation does not exist, and studies in which [Ca2+]i was elevated by means of the Ca2+ ionophore, ionomycin, further established that even a very large rise in [Ca2+]i did not cause significant NO synthesis. We furthermore found that activating adrenoceptors with NE causes synthesis of cGMP by activating a guanylyl cyclase, and that an enhanced [cGMP] evoked by use of caged cGMP causes Ca2+ release from internal stores. Thus, upon sympathetic stimulation, salivary gland acini synthesize NO that, in addition to playing a role in controlling intracellular [Ca2+]i, also might play a role in retrograde signaling processes to the surrounding tissue.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Glândulas Salivares
/
Receptores Adrenérgicos
/
Óxido Nítrico Sintase
/
Óxido Nítrico
Limite:
Animals
/
Humans
/
Male
Idioma:
En
Revista:
Adv Dent Res
Assunto da revista:
ODONTOLOGIA
Ano de publicação:
2000
Tipo de documento:
Article
País de afiliação:
Dinamarca