Perinatal changes in bombesin-stimulated muscle contraction in rabbit stomach and colon.
Perinatal changes in bombesin-stimulated muscle contraction in rabbit stomach and colon.
复制标题
兔胃和结肠中铃蟾肽刺激的肌肉收缩的围产期变化。
DOI：
10.1016/0016-5085(91)90273-n
复制
发表时间：
1991
期刊：
影响因子：
29.4
通讯作者：
Hyman,PE
中科院分区：
文献类型：
--
作者：
Yagi,H;SnapeJr,WJ;Hyman,PE
蛙皮素及其哺乳动物同源物，胃泌素释放肽，刺激平滑肌收缩，并可能促进胃肠道组织的生长。用胃底环行肌和结肠远端纵肌条等长收缩法比较新生兔和断乳兔对蛙皮素反应的变化。有一个与年龄相关的质的变化，在胃肌从双相收缩，包括相位和紧张成分在新生儿阶段的收缩，在断奶。两个年龄段的结肠收缩都是紧张性的。在这两种组织中，对最大有效浓度的氨甲酰甲胆碱的应激反应均随年龄增加5倍（P< 0.05）。相反，在胃中，观察到对蛙皮素最大有效浓度的反应的年龄相关性降低，从新生儿的2930 ± 179 mN/cm 2（对氨甲酰胆碱最大反应的98%）降至断奶时的565 ± 81 mN/cm 2（对氨甲酰胆碱最大反应的4%）（P< 0.005）。在结肠中，观察到蛙皮素的反应增加了两倍，从新生儿的446 ± 59 mN/cm 2（对氨甲酰胆碱的反应的82%）增加到断奶后的862 ± 11 mN/cm 2（对氨甲酰胆碱的反应的29%）（P< 0.05）。在任一组织中，蛙皮素的效力均未观察到年龄相关的变化。阿托品和河豚毒素都没有改变这两种组织的收缩，这表明蛙皮素直接与肌细胞相互作用。胃中的蛙皮素样免疫反应性是结肠的三倍，但两种组织中均没有与年龄相关的变化。总之，到断奶年龄，胃失去了收缩的紧张成分和80%的蛙皮素刺激的阶段性收缩的功效，这在新生儿中已经存在。效力的损失，绝对在胃和相对于氨甲酰胆碱在结肠，表明蛙皮素可能是最重要的刺激运动在新生儿期。
Bombesin and its mammalian homologue, gastrin-releasing peptide, stimulate smooth muscle contraction and may promote the growth of gastrointestinal tissues. Isometric contraction of strips from circular muscle of the gastric fundus and longitudinal muscle of the distal colon were used to compare changes in the response to bombesin in newborn and weanling rabbits. There was an age-related qualitative change in gastric muscle from biphasic contractions including phasic and tonic components in the newborn to phasic contractions alone in the weanling. The colon contractions were tonic at both ages. In both tissues there was an age-related fivefold increase in stress in response to maximally effective concentrations of bethanechol (P< 0.05). In contrast, in the stomach age-related decreases in the response to maximally effective concentrations of bombesin were observed, from 2930 ± 179 mN/cm2(98% of the maximal response to bethanechol) in the newborn to 565 ± 81 mN/cm2(4% of the maximal response to bethanechol) in the weanling (P< 0.005). In the colon, a twofold increase in response to bombesin was observed, from 446 ± 59 mN/cm2(82% of the response to bethanechol) in the newborn to 862 ± 11 mN/cm2(29% of the response to bethanechol) in the weanling (P< 0.05). No age-related changes were observed in the potency of bombesin in either tissue. Neither atropine nor tetrodotoxin altered the contractions in either tissue, suggesting that bombesin interacted directly with myocytes. There was three times as much bombesinlike immunoreactivity in the stomach compared with the colon, but no age-related changes in either tissue. In summary, by the age of weaning the stomach lost the tonic component of contraction and 80% of the efficacy of bombesin-stimulated phasic contraction that had been present in the newborn. The loss of efficacy, absolute in the stomach and relative to bethanechol in the colon, suggest that bombesin may be most important in stimulating motility in the neonatal period.