Akabane S, Matsushima Y, Torikai S, Imai M, Ito K
Eur J Pharmacol. 1986 Mar 18;122(2):181-9. doi: 10.1016/0014-2999(86)90101-9.
In order to examine the contribution of an increase in renal papillary plasma flow to the mechanism of natriuresis by atrial natriuretic polypeptide (ANP), we compared the natriuretic effects of ANP administered into the renal artery of the dog together with secretin or acetylcholine (ACh). At an equivalent renal vasodilating dose, ACh increased urinary excretion of sodium (UNaV) to 212 +/- 36% of the control associated with a decrease in urine osmolality (62 +/- 6%), whereas secretin did not change UNaV (113 +/- 12%) or urine osmolality (101 +/- 14%). This result was compatible with the view that ACh causes natriuresis mainly by increasing papillary plasma flow. Combined administration of ANP with secretin caused a marked increase in UNaV to 407 +/- 55%, in association with a decrease in urine osmolality to 55 +/- 9%, suggesting that ANP may cause natriuresis by a mechanism similar to that of ACh. Combined administration of ANP with ACh further increased UNaV to 323 +/- 67% and decreased urine osmolality to 50 +/- 6%. These observations suggest that ANP and ACh share common but not identical mechanisms of natriuretic action since ANP caused additional natriuresis during ACh infusion. These findings, however, do not necessarily exclude the possibility that ANP also inhibits renal sodium reabsorption by a direct action.
为了研究肾乳头血浆流量增加对心房利钠多肽（ANP）利钠机制的作用，我们比较了将ANP与促胰液素或乙酰胆碱（ACh）一起注入犬肾动脉时的利钠效果。在等效的肾血管舒张剂量下，ACh使尿钠排泄量（UNaV）增加至对照值的212±36%，同时尿渗透压降低（62±6%），而促胰液素未改变UNaV（113±12%）或尿渗透压（101±14%）。这一结果与ACh主要通过增加乳头血浆流量导致利钠的观点一致。ANP与促胰液素联合给药导致UNaV显著增加至407±55%，同时尿渗透压降低至55±9%，提示ANP可能通过与ACh类似的机制导致利钠。ANP与ACh联合给药进一步使UNaV增加至323±67%，尿渗透压降低至50±6%。这些观察结果表明，ANP和ACh具有共同但不完全相同的利钠作用机制，因为在ACh输注期间ANP引起了额外的利钠作用。然而，这些发现并不一定排除ANP也通过直接作用抑制肾钠重吸收的可能性。
