Del Tacca M, Soldani G, Polloni A, Bernardini C, Costa F, Bellini M
Istituto di Farmacologia Medica, University of Pisa, Italy.
J Endocrinol Invest. 1987 Oct;10(5):507-11. doi: 10.1007/BF03348181.
The effects of the antimuscarinic drugs pirenzepine and atropine on somatostatin and gastrin portal levels under basal conditions and during bethanechol infusion have been investigated in anesthetized dogs. Iv bolus administration of pirenzepine (1 mg/kg) or atropine (0.1 mg/kg), decreased gastrin concentrations, but did not affect basal somatostatin levels. During 120 min of bethanechol infusion (160 micrograms/kg/h) gastrin levels increased but somatostatin levels were unchanged. Pirenzepine (1 mg/kg iv bolus), administered at the 60th min of bethanechol infusion, decreased the gastrin concentrations, and markedly enhanced somatostatin levels. Under the same conditions atropine (0.1 mg/kg iv bolus) decreased gastrin levels, but had little or no effect on somatostatin levels. These results indicate that muscarinic receptors with similar affinity for pirenzepine and atropine mediate excitatory cholinergic influences on gastrin release. By contrast, muscarinic receptors with higher affinity for pirenzepine seem to be involved in the cholinergic inhibition of somatostatin release: by selectively blocking these receptors, pirenzepine may increase portal somatostatin levels.
在麻醉犬中，研究了抗毒蕈碱药物哌仑西平和阿托品在基础状态下以及在输注氨甲酰甲胆碱期间对生长抑素和胃泌素门静脉水平的影响。静脉推注哌仑西平（1毫克/千克）或阿托品（0.1毫克/千克）可降低胃泌素浓度，但不影响基础生长抑素水平。在输注氨甲酰甲胆碱（160微克/千克/小时）的120分钟内，胃泌素水平升高，但生长抑素水平未变。在氨甲酰甲胆碱输注第60分钟时静脉推注哌仑西平（1毫克/千克）可降低胃泌素浓度，并显著提高生长抑素水平。在相同条件下，静脉推注阿托品（0.1毫克/千克）可降低胃泌素水平，但对生长抑素水平几乎没有影响。这些结果表明，对哌仑西平和阿托品具有相似亲和力的毒蕈碱受体介导了胆碱能对胃泌素释放的兴奋作用。相比之下，对哌仑西平具有较高亲和力的毒蕈碱受体似乎参与了胆碱能对生长抑素释放的抑制作用：通过选择性阻断这些受体，哌仑西平可能会提高门静脉生长抑素水平。
