Zusammenfassung
Ein verbesserter Test zur Diagnose Renin-abhängiger Bluthochdruckformen mit dem Angiotensin II Rezeptor Antagonisten Saralasin wurde in hypertensiven Ratten, sowie in normotensiven und hypertensiven Patienten geprüft. Kumulative intravenöse Dosen, beginnend mit 0,01 µg/kg × min Saralasin wurde alle 15 Minuten um das zehnfache gesteigert. Ein signifikanter Blutdruckabfall bei der Dosis von 0,1 µg/kg × min wurde bei Ratten mit renaler Hypertonie, bei Patienten mit renaler Hypertonie und bei Patienten nach Diuretika-Vorbehandlung gefunden. Plasmaspiegel von Angiotensin I, Angiotensin II, Plasma Renin Aktivität und Saralasin wurden gemessen. Bei der niedrigsten Infusionsrate von 0,01 µg/kg × min waren die Saralasin-Konzentrationen im Plasma 40fach höher als die Plasma Angiotensin II-Konzentrationen. Der Blutdruckabfall erfolgte bei niedrigeren Dosen von Saralasin als der Anstieg von Plasma-Renin als Folge einer Hemmung des feedbacks der Reninsekretion.
Die Ergebnisse zeigen, daß Komplikationen wie schwerwiegende Blutdruckanstiege und -abfälle bei schrittweiser Erhöhung der Saralasin-Infusionsrate vermieden werden können; gleichzeitig wird die diagnostische Zuverlässigkeit des Tests erhöht. Der geringe Angiotensin-ähnliche, blutdrucksteigernde Effekt von Saralasin bei Patienten mit niedrigem Renin wird als Vorteil ausgenutzt und erhöht den Unterschied der Blutdruckantwort bei Patienten mit hohem Plasma-Renin und Blutdruckabfall nach Saralasin-Infusion.
Summary
A modification of the infusion test with saralasin, an angiotensin II antagonist for the detection of renin-dependent high blood pressure was studied in renal hypertensive rats and in normotensive and hypertensive subjects. Infusion was started at a rate of 0.01 µg/kg × min saralasin and the dose was increased ten-fold at 15 min intervals. A significant fall of diastolic blood pressure was observed at the dose of 0.1 µg/kg × min in renal hypertensive rats, in healthy subjects treated with diuretics, and in patients with renovascular hypertension (saralasin responders). Plasma concentrations of angiotensin I, angiotensin II and of saralasin as well as plasma renin activity were measured. At the lowest infusion rate of 0.01 µg/kg × min, saralasin plasma levels were 40-fold higher than plasma angiotensin II levels. The decrease in arterial blood pressure occurred at lower doses of saralasin than the increase of plasma renin due to inhibition of feedback on the renin secreting cells.
It is concluded that if the saralasin test is performed by a stepwise increase of the infusion rate, potentially dangerous complications such as hypoor hypertensive reactions can be avoided. The diagnostic reliability is improved by such a procedure since false positive and false negative responses may be prevented. The pressor effect of saralasin in non-renin dependent patients is an advantage since it causes a more marked difference of blood pressure change between saralasin responders and non-responders.
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Gless, K.H., Gram, N., Bönner, G. et al. Pharmacokinetic and pharmacodynamic studies of infusions with [Sar1, Val5, Ala8] angiotensin II (saralasin). Klin Wochenschr 56 (Suppl 1), 97–105 (1978). https://doi.org/10.1007/BF01477460
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DOI: https://doi.org/10.1007/BF01477460