Sanders M J, Soll A H
Annu Rev Physiol. 1986;48:89-101. doi: 10.1146/annurev.ph.48.030186.000513.
A model for a present view of the major pathways and receptors mediating function in the canine fundic mucosa is depicted in Figure 1. Gastrin has direct actions on the parietal cell and on the somatostatin cell; action on the parietal cell, but not somatostatin cell, is potentiated by histamine. In contrast, gastrin action on the somatostatin cell is potentiated by beta-adrenergic agonists. The potency of H2 blockers against gastrin may reflect blockage by these inhibitors of the stimulatory (parietal cell), but not the inhibitory (somatostatin cell), component of gastrin action, thus shifting the balance of gastrin effects toward the inhibitory side. The profound effects of H2 antagonists on gastrin action may also reflect an effect mediated by histamine release, but this possibility awaits direct confirmation. Cholinergic pathways also have at least dual sites of action: stimulation of the parietal cell, and blockage of the release of the inhibitory transmitter somatostatin. Anticholinergic agents may therefore have a dual acid inhibitory effect by reducing direct parietal cell stimulation and enhancing somatostatin release. There is little doubt that this model will rapidly evolve, but the concept that the pathways mediating acid secretion both converge in parallel at the parietal cell, and act in series to cause the release of paracrine transmitters, is attractive and likely to persist.
图1描绘了一个关于犬胃底黏膜中介导功能的主要途径和受体的当前观点模型。胃泌素对壁细胞和生长抑素细胞有直接作用；组胺可增强胃泌素对壁细胞的作用，但对生长抑素细胞无此作用。相反，β-肾上腺素能激动剂可增强胃泌素对生长抑素细胞的作用。H2阻滞剂对胃泌素的作用强度可能反映了这些抑制剂对胃泌素作用的刺激成分（壁细胞）的阻断，而非抑制成分（生长抑素细胞）的阻断，从而使胃泌素作用的平衡向抑制侧转移。H2拮抗剂对胃泌素作用的深远影响也可能反映了由组胺释放介导的作用，但这一可能性有待直接证实。胆碱能途径也至少有两个作用位点：刺激壁细胞，以及阻断抑制性递质生长抑素的释放。因此，抗胆碱能药物可能通过减少对壁细胞的直接刺激和增强生长抑素释放而具有双重酸抑制作用。毫无疑问，这个模型将迅速发展，但介导胃酸分泌的途径在壁细胞处平行汇聚并通过旁分泌递质的释放串联起作用的概念很有吸引力且可能会持续存在。
