On the characterization of dopamine-induced contractile response of rat anococcygeus muscle preparation.
Indian J Exp Biol
;
1994 Mar; 32(3): 176-9
Artículo
en Inglés
| IMSEAR
| ID: sea-61727
ABSTRACT
Presence of specific dopamine (DA) receptors and their characterization was attempted in rat anococcygeus muscle preparation. Dopamine (10(-6) M) and B-HT 920 (10(-6) M) produced concentration dependent contractions of the rat anococcygeus muscle preparation. The response of DA was shifted towards right in presence of haloperidol (10(-6) M; pA2 = 6.8) and sulpiride (10(-4) M) in a competitive manner. Alpha 2 antagonists yohimbine (10(-5) M) and idazoxan (10(-5) M) blocked the response to DA in a competitive manner, while alpha 1 antagonist prazosin (10(-5) M) completely blocked the response to DA. SCH 23390 (10(-5) M), a D1 DA antagonist potentiated the response to DA. Reserpinization (5 mg/kg, 24 hr prior) brought about a shift towards the right, and this response was similarly blocked by haloperidol, sulpiride and yohimbine without affecting the maximum response. Desipramine (10(-5) M) blocked the response of DA in a non-competitive manner. Pretreatment of animals with desipramine (10 mg/kg) followed by reserpine, brought about a reversal of action of reserpine. The response to B-HT 920 (10(-6) M), was blocked similarly by haloperidol and yohimbine. However, the effect of desipramine was more pronounced when compared to DA per se. SKF 38393, a D1 DA agonist, potentiated the response to B-HT 920. The findings suggest the presence of both D1 and D2 DA receptors in rat anococcygeus muscle and that DA also acts on adrenergic receptors to produce a contractile response of this muscle preparation.
Texto completo:
Disponible
Índice:
IMSEAR (Asia Sudoriental)
Asunto principal:
Ratas
/
Reserpina
/
Sulpirida
/
Azepinas
/
Yohimbina
/
Benzazepinas
/
Femenino
/
Masculino
/
Prazosina
/
Dopamina
Idioma:
Inglés
Revista:
Indian J Exp Biol
Año:
1994
Tipo del documento:
Artículo
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