Biomaterial Database

Role of the tissue renin-angiotensin system in the action of angiotensin-converting enzyme inhibitors. 1995

Y Tokita, and H Oda, and R Franco-Saenz, and P J Mulrow

Department of Medicine, Medical College of Ohio, Toledo 43699.

The mechanism of the blood pressure-lowering action of chronic administration of angiotensin-converting enzyme (ACE) inhibitors is still controversial. We investigated the effects of the ACE inhibitors, captopril and perindopril, on the renin-angiotensin system (RAS) in plasma and tissues (adrenal gland and kidney) in the rat. Captopril or perindopril was infused intraperitoneally into rats via a mini-osmotic pump for 6 days at a rate of 0.5 or 0.25 mg/kg/hr, respectively. Perindopril markedly increased plasma renin concentration (PRC) from 12.7 +/- 1.1 to 867 +/- 59 ng Ang I/ml/hr and significantly inhibited plasma angiotensin II (Ang II) from 17.5 +/- 3.5 to 7.8 +/- 0.6 pg/ml and plasma ACE activity from 31.6 +/- 1.7 to 1.7 +/- 0.3 U/liter. Captopril also increased PRC from 12.1 +/- 2.1 to 147 +/- 17 ng Ang I/ml/hr. However, it did not inhibit plasma Ang II (20.6 +/- 1.9 vs 22.0 +/- 2.1 pg/ml, N.S.) and increased plasma ACE activity from 35.9 +/- 1.8 to 65.0 +/- 4.8 U/liter. Perindopril increased kidney renin from 625.3 +/- 84.6 to 2152.3 +/- 233.4 micrograms/g/hr, while captopril produced a modest but insignificant rise in kidney renin (708.0 +/- 107.1 vs 1083.3 +/- 155.5 micrograms Ang I/g/hr, N.S.). On the other hand, both captopril and perindopril decreased adrenal Ang II significantly (from 21.1 +/- 2.7 to 9.2 +/- 0.5 pg/capsule and from 15.5 +/- 2.9 to 2.0 +/- 0.6 pg/capsule, respectively). Adrenal renin was not altered by either treatment. In spite of no inhibition of plasma Ang II, the pressor response to intravenous Ang I was still suppressed after captopril treatment. Both captopril and perindopril lowered the blood pressure of the rats significantly. Our results support the hypothesis that inhibition of tissue RAS is important for the hypotensive action of ACE inhibition.

UI	MeSH Term	Description	Entries
D007211	Indoles	Benzopyrroles with the nitrogen at the number one carbon adjacent to the benzyl portion, in contrast to ISOINDOLES which have the nitrogen away from the six-membered ring.
D007263	Infusions, Parenteral	The administration of liquid medication, nutrient, or other fluid through some other route than the alimentary canal, usually over minutes or hours, either by gravity flow or often by infusion pumping.	Intra-Abdominal Infusions,Intraperitoneal Infusions,Parenteral Infusions,Peritoneal Infusions,Infusion, Intra-Abdominal,Infusion, Intraperitoneal,Infusion, Parenteral,Infusion, Peritoneal,Infusions, Intra-Abdominal,Infusions, Intraperitoneal,Infusions, Peritoneal,Intra Abdominal Infusions,Intra-Abdominal Infusion,Intraperitoneal Infusion,Parenteral Infusion,Peritoneal Infusion
D007668	Kidney	Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.	Kidneys
D008297	Male		Males
D012083	Renin	A highly specific (Leu-Leu) endopeptidase that generates ANGIOTENSIN I from its precursor ANGIOTENSINOGEN, leading to a cascade of reactions which elevate BLOOD PRESSURE and increase sodium retention by the kidney in the RENIN-ANGIOTENSIN SYSTEM. The enzyme was formerly listed as EC 3.4.99.19.	Angiotensin-Forming Enzyme,Angiotensinogenase,Big Renin,Cryorenin,Inactive Renin,Pre-Prorenin,Preprorenin,Prorenin,Angiotensin Forming Enzyme,Pre Prorenin,Renin, Big,Renin, Inactive
D012084	Renin-Angiotensin System	A BLOOD PRESSURE regulating system of interacting components that include RENIN; ANGIOTENSINOGEN; ANGIOTENSIN CONVERTING ENZYME; ANGIOTENSIN I; ANGIOTENSIN II; and angiotensinase. Renin, an enzyme produced in the kidney, acts on angiotensinogen, an alpha-2 globulin produced by the liver, forming ANGIOTENSIN I. Angiotensin-converting enzyme, contained in the lung, acts on angiotensin I in the plasma converting it to ANGIOTENSIN II, an extremely powerful vasoconstrictor. Angiotensin II causes contraction of the arteriolar and renal VASCULAR SMOOTH MUSCLE, leading to retention of salt and water in the KIDNEY and increased arterial blood pressure. In addition, angiotensin II stimulates the release of ALDOSTERONE from the ADRENAL CORTEX, which in turn also increases salt and water retention in the kidney. Angiotensin-converting enzyme also breaks down BRADYKININ, a powerful vasodilator and component of the KALLIKREIN-KININ SYSTEM.	Renin-Angiotensin-Aldosterone System,Renin Angiotensin Aldosterone System,Renin Angiotensin System,System, Renin-Angiotensin,System, Renin-Angiotensin-Aldosterone
D001794	Blood Pressure	PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.	Systolic Pressure,Diastolic Pressure,Pulse Pressure,Pressure, Blood,Pressure, Diastolic,Pressure, Pulse,Pressure, Systolic,Pressures, Systolic
D002216	Captopril	A potent and specific inhibitor of PEPTIDYL-DIPEPTIDASE A. It blocks the conversion of ANGIOTENSIN I to ANGIOTENSIN II, a vasoconstrictor and important regulator of arterial blood pressure. Captopril acts to suppress the RENIN-ANGIOTENSIN SYSTEM and inhibits pressure responses to exogenous angiotensin.	(S)-1-(3-Mercapto-2-methyl-1-oxopropyl)-L-proline,Capoten,Lopirin,SQ-14,225,SQ-14,534,SQ-14225,SQ-14534,SQ 14,225,SQ 14,534,SQ 14225,SQ 14534,SQ14,225,SQ14,534,SQ14225,SQ14534
D000311	Adrenal Glands	A pair of glands located at the cranial pole of each of the two KIDNEYS. Each adrenal gland is composed of two distinct endocrine tissues with separate embryonic origins, the ADRENAL CORTEX producing STEROIDS and the ADRENAL MEDULLA producing NEUROTRANSMITTERS.	Adrenal Gland,Gland, Adrenal,Glands, Adrenal
D000804	Angiotensin II	An octapeptide that is a potent but labile vasoconstrictor. It is produced from angiotensin I after the removal of two amino acids at the C-terminal by ANGIOTENSIN CONVERTING ENZYME. The amino acid in position 5 varies in different species. To block VASOCONSTRICTION and HYPERTENSION effect of angiotensin II, patients are often treated with ACE INHIBITORS or with ANGIOTENSIN II TYPE 1 RECEPTOR BLOCKERS.	Angiotensin II, Ile(5)-,Angiotensin II, Val(5)-,5-L-Isoleucine Angiotensin II,ANG-(1-8)Octapeptide,Angiotensin II, Isoleucine(5)-,Angiotensin II, Valine(5)-,Angiotensin-(1-8) Octapeptide,Isoleucine(5)-Angiotensin,Isoleucyl(5)-Angiotensin II,Valyl(5)-Angiotensin II,5 L Isoleucine Angiotensin II,Angiotensin II, 5-L-Isoleucine