Las soluciones experimentales fueron utilizadas en las siguientes concentraciones finales: bloqueador de canal lento de [Na.sup.+], amiloride (Sigma), 0.2, 0.02 y 0.002 [micron]M; bloqueador de canal tipo L de [Ca.sup.2+], nifedipina (Sigma), 0.5 [micron]M; solucion activadora del intercambiador [Na.sup.+]/[Ca.sup.2+], Tyrode
conteniendo [Na.sup.+] 80 mM.
The pellets were resuspended into Tyrode
HEPES buffer, pH 7.35, and platelets were counted with a thrombocoulter counter.
After overnight fasting (10-12 h), the rats were anesthetized with diethyl ether and the small intestine at the ileocecal junction was isolated and rinsed with Tyrode
buffer solution pH 7.4 (containing in mM: 15 glucose, 11.90 NaHC[O.sub.3], 136.9 NaCl, 4.2 Na[H.sub.2]P[O.sub.4], 2.7 KCl, 1.2 Ca[Cl.sub.2], and 0.5 Mg[Cl.sub.2]) at room temperature.
Then, hearts were rapidly removed, mounted on a Langendorff perfusion apparatus, and retrogradely perfused with [Ca.sup.2+]-free tyrode
solution composed of (in mM) NaCl 120, KCl 5.4, Mg[Cl.sub.2] 0.5, HEPES 25, and glucose 10 (pH 7.4 with NaOH) at 37[degrees] C.
The intestine was immediately placed in 37 C and oxygenated ([O.sub.2]/[CO.sub.2], 95%:5%) in Tyrode
The rats and guinea pig were killed by a blow on the head dissected for the parts were placed in dishes containing Tyrode
Briefly, PRP containing 5 mM EDTA, 2U/mL apyrase, and 0.1 [micro]g/mL PGE1 was centrifuged at 1100 xg for 10 min, and then pellets were resuspended in Tyrode
buffer and the concentration of platelets was adjusted to approximately 3 x [10.sup.7] platelets/mL.
Acetylcholine, atropine, modified Tyrode
's Salt Solution, and N[omega]-nitro-L-arginine methyl ester hydrochloride were acquired from Sigma-Aldrich Chemical Co.
The hearts were quickly removed and washed with cool and oxygenated Tyrode
Each group was divided into two groups for the isolated heart perfusion, according to the perfusion solution utilized (Tyrode