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A CRYSTALLINE PRESSOR SUBSTANCE (ANGIOTONIN) RESULTING FROM THE REACTION BETWEEN RENIN AND RENIN-ACTIVATOR
1Lilly Laboratory for Clinical Research, Indianapolis City Hospital, Indianapolis.
The Journal of Experimental Medicine
|October 30, 2009
Summary
Renin-activator interacts with renin to create angiotonin, a potent pressor substance. This newly identified compound causes significant arterial pressure increases and exhibits unique physiological effects distinct from adrenaline.
Area of Science:
- Biochemistry
- Physiology
- Pharmacology
Background:
- Renin, an enzyme, is known to influence blood pressure.
- The precise nature and physiological effects of renin's interaction products were not fully understood.
Purpose of the Study:
- To characterize the substance formed by the reaction of renin with its activator.
- To investigate the physiological effects of this pressor substance, termed angiotonin.
Main Methods:
- Chemical characterization of the pressor substance (heat stability, solubility, reactivity).
- Intravenous injection studies in animals to assess pressor effects.
- Comparative studies with adrenaline and assessment of interfering substances.
- Optimization of reaction conditions for angiotonin yield.
- In vitro incubation studies with renin.
- Ex vivo studies on intestinal segments and perfused ear vessels.
Main Results:
- A heat-stable, soluble pressor substance, angiotonin, was identified.
- Angiotonin induces a rapid and significant increase in arterial blood pressure.
- Angiotonin's pressor action is distinct from adrenaline and unaffected by cocaine, atropine, or stilbestrol.
- Optimal yield of angiotonin achieved with a specific renin-activator ratio and temperature.
- Renin inactivates angiotonin.
- Angiotonin causes intestinal contraction and vascular constriction in perfused vessels.
Conclusions:
- Angiotonin is a potent vasoactive peptide with significant pressor activity.
- Its physiological effects and interactions provide insights into the renin-angiotensin system.
- Angiotonin represents a distinct pharmacological entity with potential implications for cardiovascular research.
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