Sandor P, de Jong W, de Wied D
Rudolf Magnus Institute for Pharmacology, Medical Faculty, University of Utrecht, The Netherlands.
Peptides. 1988 Mar-Apr;9(2):215-9. doi: 10.1016/0196-9781(88)90253-7.
The influence of intracerebroventricularly (ICV) administered thyrotropin-releasing hormone pGlu-His-Pro-NH2 (TRH), pGlu-His-Phe-NH2 (TRH analog, (TRHa)), Met-Glu-His-Phe(ACTH-(4-7)) and His-Phe-Arg-Trp-Gly (ACTH-(6-10)) on autoregulation of cerebral blood flow was studied in anesthetized, ventilated rats. Autoregulatory capacity of the cerebrovascular bed was tested by hypothalamic blood flow (HBF) and total cerebral blood volume (CBV) determinations during consecutive stepwise lowering of the systemic mean arterial pressure to 80, 60 and 40 mmHg, by hemorrhage. None of the peptides caused a change in resting HBF or CBV upon ICV administration (5 micrograms/kg). However, the same dose of TRH, TRHa and ACTH-(4-7) resulted in impairment of autoregulation. ACTH-(6-10) was not effective. Thus, the disturbed autoregulation may be due to the presence of the dipeptide Glu-His which is common to TRH, TRHa and ACTH-(4-7).
在麻醉、通气的大鼠中，研究了脑室内（ICV）注射促甲状腺激素释放激素pGlu-His-Pro-NH2（TRH）、pGlu-His-Phe-NH2（TRH类似物，（TRHa））、Met-Glu-His-Phe（促肾上腺皮质激素-（4-7））和His-Phe-Arg-Trp-Gly（促肾上腺皮质激素-（6-10））对脑血流自动调节的影响。通过在连续逐步将全身平均动脉压降至80、60和40 mmHg（通过放血）的过程中测定下丘脑血流（HBF）和全脑血容量（CBV），来测试脑血管床的自动调节能力。脑室内注射（5微克/千克）这些肽后，均未引起静息HBF或CBV的变化。然而，相同剂量的TRH、TRHa和促肾上腺皮质激素-（4-7）导致自动调节功能受损。促肾上腺皮质激素-（6-10）无效。因此，自动调节功能紊乱可能是由于TRH、TRHa和促肾上腺皮质激素-（4-7）中共同存在的二肽Glu-His所致。
