Acute tubular necrosis due to captopril

Tailoring the management of hypertension to comorbidities

PURPOSE OF REVIEW

In this article, we review the most current evidence for initiation and maintenance of various antihypertension (HTN) drug classes, including other misconceptions with respect to common comorbidities in patients with HTN.

RECENT FINDINGS

Although the currently available anti-HTN agents have broad applicability in treating HTN, additional agents, such as angiotensin receptor-neprilysin inhibitors and novel nonsteroidal mineralocorticoid antagonists, have recently gained clinical significance. In addition, there have been some anecdotal concerns regarding the adverse effects, indications, and risks of COVID-19 infection/mortality when using certain anti-HTN agents.

SUMMARY

Current guidelines currently address the treatment of primary HTN. However, isolated HTN is uncommon and often involves comorbid diseases that require specific regimentation. Several experimental medications are currently in late-stage trials showing potential superiority over current drugs that are available in the market.

Preparation and Identification of Novel Antihypertensive Peptides from the In Vitro Gastrointestinal Digestion of Marine Cobia Skin Hydrolysates

This research focuses on cobia skin hydrolysates and their antihypertensive effects via the inhibitory activities of angiotensin I-converting enzyme (ACE). Marine fish Cobia (Rachycentron canadum) skin was hydrolysed for 5 h using Protamex and Protease N to obtain the cobia skin protein hydrolysates PX-5 and PN-5, respectively. The soluble protein and peptide contents of the PX-5 were 612 and 270 mg/g, respectively, and for the PN-5, 531 and 400 mg/g, respectively. The IC₅₀ of PX-5 and PN-5 on ACE was 0.221 and 0.291 mg/mL, respectively. Increasing the IC₅₀ from 0.221 to 0.044 mg/mL by simulated gastrointestinal digestion (PX-5G) reduced the ACE-inhibitory capacity of PX-5. Using gel filtration chromatography, the PX-5G was fractioned into eight fractions. The molecular weight of the fifth fraction from PX-5G was between 630 and 450 Da, and the highest inhibitory efficiency ratio on ACE was 1552.4%/mg/mL. We identified four peptide sequences: Trp-Ala-Ala, Ala-Trp-Trp, Ile-Trp-Trp, and Trp-Leu, with IC₅₀ values for ACE of 118.50, 9.40, 0.51, and 26.80 μM, respectively. At a dose of 600 mg PX-5 powder/kg body weight, in spontaneously hypertensive rats PX-5's antihypertensive effect significantly reduced systolic and diastolic blood pressure by 21.9 and 15.5 mm Hg, respectively, after 4 h of oral gavage.

Purification and Identification of Angiotensin I-Converting Enzyme Inhibitory Peptides and the Antihypertensive Effect of Chlorella sorokiniana Protein Hydrolysates

Hot water was used to obtain Chlorella sorokiniana hot water extract (HWE). Subsequently, this byproduct was freeze-dried, hydrolysed at 50 °C using Protease N to obtain C. sorokiniana protein hydrolysates (PN-1), and then digested with a gastrointestinal enzyme (PN-1G). The inhibitory effects of the HWE and hydrolysates against angiotensin I-converting enzyme (ACE) were investigated. The soluble protein and peptide contents were 379.9 and 179.7 mg/g, respectively, for HWE and 574.8 and 332.8 mg/g, respectively, for PN-1. The IC₅₀ values of the HWE, PN-1, and PN-1G on ACE were 1.070, 0.035, and 0.044 mg/mL, respectively. PN-1G was separated into seven fractions through size exclusion chromatography. The sixth fraction of the hydrolysate had a molecular weight between 270 and 340 Da, and the lowest IC₅₀ value on ACE was 0.015 mg/mL. The amino acid sequences of the ACE-inhibitory peptides were Trp-Val, Val-Trp, Ile-Trp, and Leu-Trp, of which the IC₅₀ values were 307.61, 0.58, 0.50, and 1.11 µΜ, respectively. Systolic blood pressure and diastolic blood pressure were reduced 20 and 21 mm Hg, respectively, in spontaneously hypertensive rats after 6 h of oral administration with a dose of 171.4 mg PN-1 powder/kg body weight.

Captopril induced reversible acute renal failure in a premature neonate with double outlet right ventricle and congestive heart failure

BACKGROUND

captopril is well tolerated in most patients. There is no report of acute deterioration in renal function after administration of captopril in neonates with congestive heart failure secondary to congenital heart defects with large left-to-right shunts.

METHODS

we report a premature neonate with double outlet right ventricle and congestive heart failure who developed acute renal failure after administration of captopril at a low dose of 0.1 mg/kg per 8 hours.

RESULTS

on the third day after captopril therapy, the levels of serum creatinine and blood urea nitrogen increased to 2.6 mg/dl and 73 mg/dl respectively, and hyperkalemia appeared. Captopril was discontinued immediately. On the fourth day, the infant developed oliguria which persisted for 24 hours and resolved on the fifth day when the serum potassium normalized to 4.5 mmol/L. The level of serum creatinine peaked at 3.9 mg/dL on the sixth day and gradually decreased to normal on the ninth day after administration of captopril. The captopril-induced acute renal failure resolved completely after cessation of the drug.

CONCLUSIONS

attention should be given to captopril therapy in premature neonates with congestive heart failure secondary to congenital heart disease with large left-to-right shunts. Routine hemodynamic examination and biochemical monitoring are suggested before and during captopril therapy.

Human meprin alpha and beta homo-oligomers: cleavage of basement membrane proteins and sensitivity to metalloprotease inhibitors

Meprin is a zinc endopeptidase of the astacin family, which is expressed as a membrane-bound or secreted protein in mammalian epithelial cells, in intestinal leucocytes and in certain cancer cells. There are two types of meprin subunits, alpha and beta, which form disulphide-bonded homo- and hetero-oligomers. Here we report on the cleavage of matrix proteins by hmeprin (human meprin) alpha and beta homo-oligomers, and on the interactions of these enzymes with inhibitors. Despite their completely different cleavage specificities, both hmeprin alpha and beta are able to hydrolyse basement membrane components such as collagen IV, nidogen-1 and fibronectin. However, they are inactive against intact collagen I. Hence the matrix-cleaving activity of hmeprin resembles that of gelatinases rather than collagenases. Hmeprin is inhibited by hydroxamic acid derivatives such as batimastat, galardin and Pro-Leu-Gly-hydroxamate, by TAPI-0 (tumour necrosis factor alpha protease inhibitor-0) and TAPI-2, and by thiol-based compounds such as captopril. Therapeutic targets for these inhibitors are MMPs (matrix metalloproteases), TACE (tumour necrosis factor alpha-converting enzyme) and angiotensin-converting enzyme respectively. The most effective inhibitor of hmeprin alpha in the present study was the naturally occurring hydroxamate actinonin ( K(i)=20 nM). The marked variance in the cleavage specificities of hmeprin alpha and beta is reflected by their interaction with the TACE inhibitor Ro 32-7315, whose affinity for the beta subunit (IC50=1.6 mM) is weaker by three orders of magnitude than that for the alpha subunit ( K(i)=1.6 microM). MMP inhibitors such as the pyrimidine-2,4,6-trione derivative Ro 28-2653 that are more specific for gelatinases do not bind to hmeprin, presumably due to the subtle differences in the mode of zinc binding and active-site structure between the astacins and the MMPs.