THE INFLUENCE OF THE VAGALLY INDUCED REBOUND CONTRACTIONS ON THE NONADRENERGIC, NONCHOLINERGIC (NANC) INHIBITORY MOTILITY OF THE RABBIT STOMACH AND THE ROLE OF PROSTAGLANDINS

被引:15
作者
BACCARI, MC [1 ]
CALAMAI, F [1 ]
STADERINI, G [1 ]
机构
[1] UNIV FLORENCE,DEPT PHYSIOL,VIALE MORGAGNI 63,I-50134 FLORENCE,ITALY
来源
JOURNAL OF THE AUTONOMIC NERVOUS SYSTEM | 1992年 / 37卷 / 02期
关键词
NANC VAGAL STIMULATION; REBOUND CONTRACTION; PROSTAGLANDIN; GASTRIC INHIBITORY MOTILITY PATTERN;
D O I
10.1016/0165-1838(92)90241-8
中图分类号
Q189 [神经科学];
学科分类号
071006 ;
摘要
Factors influencing the vagally induced rebound contraction and its role in gastric inhibitory motility were studied in the anaesthetised rabbit. Gastric motility was assessed from measurements of gastric volume by means of an intragastric balloon. In the atropine- and guanethidine-treated animals, vagal stimulation caused biphasic motor responses: a rapid relaxation was followed by a rebound contraction. The latter, depending on experimental conditions, was able to restore and maintain gastric volume at the basal level. However, the rebound contraction was greatly influenced by the stimulation parameters and the basal gastric volume. Stimulation periods of less than 30 sec, or stimulation frequencies above 20 Hz, as well as basal gastric volumes above 70 ml could reduce the amplitude of the post-stimulus excitatory motility, and transformed the biphasic response into a triphasic one: a slow, long-lasting relaxation appeared after the rebound contraction. Prostaglandin-synthesis inhibitors of the non-steroidal anti-inflammatory group depressed the rebound contraction, and caused persistance of gastric relaxation, even after the offset of vagal stimulation. PGE2 evoked excitatory motor responses which closely mimicked the vagally induced rebound contraction. PGE2 also interrupted the rapid or slow, long-lasting relaxant responses. PGF2-alpha elicited tonic excitatory responses. These results suggest that PGE2 is involved in the mechanism underlying post-stimulus excitatory motility. They also suggest that the rebound contraction is a key factor in determining the inhibitory motility pattern of the rabbit stomach.
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页码:125 / 135
页数:11
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