Spontaneous contractions of intestinal smooth muscle re-aggregates from the new-born rat triggered by thromboxane A2.
J Vet Med A Physiol Pathol Clin Med
; 47(8): 469-75, 2000 Oct.
Article
en En
| MEDLINE
| ID: mdl-11075538
Isolated smooth muscle cells from the small intestine of new-born rats were prepared by enzymatic digestion. These cells re-aggregate after 1 day in culture to clusters. The re-aggregates show spontaneous rhythmical contractions at 37 degrees C with a frequency (13.1 +/- 0.8 min-1, n = 49), which is similar to that of the intact smooth muscle layer. The cholinergic agonist carbachol (5 x 10(-5) mol l-1) caused an increase in the frequency of the spontaneous contractions often ending in a permanent contraction. A similar effect was achieved with the thromboxane A2 (TXA2) agonist, U-46619 (10(-5) mol l-1). In contrast, both the TXA2 receptor blocker, Bay u3405 (5 x 10(-4) mol l-1), as well as the Ca2+ channel blocker, verapamil (5 x 10(-5) mol l-1), suppressed the spontaneous contractions. The observed contractility was insensitive against the neuronal blocker tetrodotoxin (10(-6) mol l-1). These analyses of video images were supported by the measurement of relative changes in the intracellular Ca2+ concentration with the Ca(2+)-sensitive dye, fura-2. Spontaneous contractions were paralleled by spikes in the intracellular Ca2+ concentration, which were abolished by Bay u3405, but stimulated by U-46619 or carbachol. In summary, these results obtained at re-aggregates of intestinal smooth muscle cells support the hypothesis of a role of TXA2 in the generation of spontaneous intestinal smooth muscle contractions in vitro.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Tromboxano A2
/
Intestino Delgado
/
Contracción Muscular
/
Músculo Liso
Límite:
Animals
Idioma:
En
Revista:
J Vet Med A Physiol Pathol Clin Med
Año:
2000
Tipo del documento:
Article
País de afiliación:
Alemania
Pais de publicación:
Alemania