Cysteine blood pressure

Natriuretic peptides are a family of peptide hormones. All of them contain a 17-amino acid long ring that is closed by a disulfide bond between two cysteine residues. ANP (atrial natriuretic peptide) is mainly expressed in the atria of the heart, whereas BNP (B-type natriuretic peptide) is synthesized in the ventricular myocardium. CNP occurs mainly in the endothelium and is thought to have a paracrine function. ANF and BNF lower blood pressure by a direct effect on smooth muscle and on the salt retention in the kidney. Natriuretic peptides bind and activate particulate guanylyl cyclases. 

Physiologists had postulated for a long time about the existence of a sodium excreting hormone to prevent Na overload and consequent deleterious effects of high blood pressure on the heart and vascular system. At least two such natriuretic factors have been described atrial or A-type and brain or B-type natriuretic factors. Structurally, the natriuretic factors are peptides with a cysteine-cysteine disulfide bridge creating a characteristic loop , this is illustrated by Figure 8.8. 

One of the major effects of NO is to induce the relaxation of smooth muscle of blood vessels, an important factor in the regulation of blood pressure. Hemoglobin can carry NO both on its heme and on the thiol group of cysteine (393.174/175 The affinity for NO is high in the T state and low in the R state. This allows hemoglobin to carry NO from the lungs to tissues, where it can be released and participate in the regulation of blood pressure.174 179... 

One of the goals of synthetic medicinal chemistry is to design potent inilibitors of clinically important proteases. Elastase inhibitors may be useful for treatment of emphysema, pancreatitis, and arthritis,a/b while inhibitors of the angiotensinogen-converting enzyme or of renin (Box 22-D) can help control blood pressure. Inhibition of thrombin, factor Xa, or other blood clotting factors (Fig. 12-17) may prevent blood clots and inhibition of the cytosolic tryptase may provide a new treatment for asthma. Inhibition of the cysteine protease cathepsin K may help combat osteoporosis and inhibition of cysteine proteases of corona viruses may fight the common cold. Cysteine proteases of schistosomes are also targets for protease inhibitors.c... 

Deamino- cysteine- 8-D-arginine vasopressin (dDAVP) Treatment of diabetes insipidus, Alzheimer s disease, modulation of blood pressure Rat Aerosol dDAVP transport over respiratory tract via passive transepithelial transport process [83]... 

To further emphasize the double face (Janus face) of the molecule, it has been recently demonstrated that the transfer of a NO group to cysteine sulfhydryls on proteins, known as S-nitrosylation, is a ubiquitous regulatory reaction. It represents a form of redox modulation in diverse tissues. Nitrosylated proteins are relevant in many processes ranging from signal transduction, DNA repair, host defence, and blood pressure control to ion channel regulation and neurotransmission [56]. 

DNIC with thiol-containing ligands as NO donors can also initiate penis erection was supported by experimental data. Intracavemous injections of aqueous solutions of DNIC with cysteine or glutathione (0.6-6 pmol/kg) to male rats stimulated the dose-dependent erective activity in rats with innervated and surgically denervated penises, which lasted 2—3 min [98]. The extent of erection was estimated by the level of blood pressure in the cavernous bodies with simultaneous monitoring of mean AP. In experiments where DNIC were administered by intravenous route, penis erection did not occur despite a significant decrease of systemic blood pressure. 

Prostate-specific membrane antigen (PSMA) is a type II integral membrane protein expressed on the surface of prostate cancer (PCa) cells, particularly in androgen-independent, advanced, and metastatic disease. N-[N-[(S)-l,3-dicarboxypropyl]carbamoyl]-4- F-fluorobenzyl-L-cysteine ( F-DCFBC) could image an experimental model of PSMA-positive PCa using PET. Three adverse events occurred in five patients with metastatic PCa who received intravenous administration of 370 MBq (10 mCi) of F-DCFBC. Two patients experienced grade three blood pressure events using the CTCAE. A third patient experienced lower back pain. Patients did not experience any severe adverse events [til ll. 

Oxytocin, which is produced in the pituitary gland, causes the contraction of smooth muscle, including the uterus. It is used clinically to induce labor or to increase the strength of uterine contractions. Vasopressin, another pituitary hormone, regulates the secretion of water by the kidneys and affects blood pressure. The structures of vasopressin and oxytocin differ by only two amino acids. They are cyclic peptides that are hnked by a disulfide bond between two cysteine residues. 

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