Castellino P, Hunt W, DeFronzo R A
Department Medicine, Yale University School of Medicine, New Haven, Connecticut.
Kidney Int Suppl. 1987 Oct;22:S15-20.
Our results as well as those in the literature suggest that some hormone or combination of hormones, that are inhibited by somatostatin, is responsible for the hyperfiltration response following amino acid infusion/protein ingestion. Recently, we have infused amino acids with somatostatin and replaced the stimulated levels of insulin/glucagon/growth hormone observed during amino acid infusion alone (Castellino and DeFronzo, preliminary results). This combined hormone replacement was able to overcome the inhibitory effect of somatostatin and return the increase in RPF and GFR to the elevated levels observed following amino acid infusion. These results suggest that some combination of these hormones is involved in the hyperfiltration response to hyperaminoacidemia. However, several comments are worthy of emphasis. First, somatostatin is known to inhibit a number of hormones (Table 1), and a contributory role for any of these should not be excluded. Second, a large body of evidence has accumulated to indicate that neither insulin, glucagon, nor growth hormone alone are capable of augmenting either RPF or GFR. The possibility that infusion of the three hormones together will increase RPF and GFR, when neither hormone alone will do so, has not been examined. More likely, some interaction between the elevated plasma amino acid concentrations and the elevated hormone levels is responsible for the hyperfiltration response. It is interesting to speculate that such an interaction might be exerted at the level of the kidney by an effect on renal amino acid metabolism.
我们的研究结果以及文献中的结果表明，某些受生长抑素抑制的激素或激素组合，是氨基酸输注/蛋白质摄入后高滤过反应的原因。最近，我们将氨基酸与生长抑素一起输注，并补充了单独输注氨基酸期间观察到的胰岛素/胰高血糖素/生长激素的刺激水平（Castellino和DeFronzo，初步结果）。这种联合激素补充能够克服生长抑素的抑制作用，并使肾血浆流量（RPF）和肾小球滤过率（GFR）的增加恢复到氨基酸输注后观察到的升高水平。这些结果表明，这些激素的某种组合参与了对高氨基酸血症的高滤过反应。然而，有几点值得强调。首先，已知生长抑素会抑制多种激素（表1），不应排除其中任何一种激素的作用。其次，大量证据表明，单独的胰岛素、胰高血糖素或生长激素都不能增加RPF或GFR。尚未研究当单独一种激素都不能增加RPF和GFR时，三种激素一起输注是否会增加RPF和GFR。更有可能的是，血浆氨基酸浓度升高与激素水平升高之间的某种相互作用是高滤过反应的原因。有趣的是，可以推测这种相互作用可能通过对肾脏氨基酸代谢的影响在肾脏水平上发挥作用。
