A comparison of the vasopressin response of rats to intraperitoneal and intravenous administration of hypertonic saline, and the effect of opioid and aminergic antagonists.
A comparison of the vasopressin response of rats to intraperitoneal and intravenous administration of hypertonic saline, and the effect of opioid and aminergic antagonists.
复制标题
大鼠对腹腔内和静脉内给予高渗盐水的加压素反应以及阿片类药物和胺能拮抗剂的作用的比较。
作者：
M. Forsling;C. Matziari;L. Aziz
比较了大鼠腹腔注射高渗氯化钠（1.5 mol/l）和静脉输注1.05 mol/l氯化钠后的加压素反应。这两种制度产生了类似的加压素反应的渗透阈值，虽然血浆加压素水平对血浆渗透压的曲线的斜率是不相同的。纳洛酮和左洛啡烷预处理增加了静息状态下的加压素水平，并通过降低激素释放的渗透阈值来有效增强加压素对高渗盐水的反应。因此，阿片肽似乎在静息和刺激条件下对加压素释放发挥抑制作用。肾上腺素受体拮抗剂普萘洛尔，苯氧苄明和酚妥拉明产生的休息加压素浓度下降，而普萘洛尔和苯氧苄明增强加压素的渗透释放与渗透阈值下降。这表明去甲肾上腺素能通路在静息时是兴奋性的，同时对渗透反应具有抑制作用。甲氧氯普胺也引起静息血浆加压素浓度下降，同时增加渗透反应。相反，氟哌啶醇不影响加压素反应。
The vasopressin response of rats to i.p. injection of hypertonic sodium chloride (1.5 mol/l) was compared with that following i.v. infusion of 1.05 mol sodium chloride/l. The two regimes produced a similar vasopressin response in terms of the osmotic threshold, although the slopes of the plot of plasma vasopressin levels against plasma osmolality were not identical. Pretreatment with naloxone and levallorphan increased the resting vasopressin levels and effectively potentiated vasopressin release in response to hypertonic saline by reducing the osmotic threshold for hormone release. Thus, opioid peptides appear to exert an inhibitory effect on vasopressin release under resting and stimulated conditions. The adrenoreceptor antagonists propranolol, phenyoxybenzamine and phentolamine produced a fall in resting vasopressin concentrations while propranolol and phenoxybenzamine potentiated the osmotic release of vasopressin in association with a fall in the osmotic threshold. This would suggest that noradrenergic pathways are excitatory at rest while having an inhibitory effect on the osmotic response. Metoclopramide also produced a fall in resting plasma vasopressin concentrations while increasing the osmotic response. In contrast haloperidol did not affect the vasopressin response.