The stability of collagen, the most abundant protein in humans and many animals, is related to the hydroxylation of L-proline, a post-translational modification occurring at carbon 3 and 4 on its pyrrolidine ring. Collagens of different origins have shown different proline hydroxylation levels, making hydroxyprolines useful biomarkers in structure characterizations. The presence of two chiral carbon atoms, 3-hydroxyproline and 4-hydroxyproline, results in eight stereoisomers (four pairs of enantiomers) whose quantitation in collagen hydrolysates requires enantioselective analytical methods. Capillary electrophoresis was applied for the separation and quantitation of the eight stereoisomers of 3- and 4-hydroxyproline and D,L-proline in collagen hydrolysates. The developed method is based on the derivatization with the chiral reagent (R)-(-)-4-(3-Isothiocyanatopyrrolidin-yl)-7-nitro-2,1,3-benzoxadiazole, enabling the use of a light-emitting diode-induced fluorescence detector for high sensitivity. The separation of the considered compounds was accomplished in less than 10 min, using a 500 mM acetate buffer pH 3.5 supplemented with 5 mM of heptakis(2,6-di-O-methyl)-β-cyclodextrin as the chiral selector. The method was fully validated and showed the adequate sensitivity for the application to samples of collagen hydrolysates. The analysis of samples extracted from chicken Pectoralis major muscles affected by growth-related myopathies showed different stereoisomer patterns compared to those from the unaffected control samples.

• Keywords
• capillary electrophoresis, chiral separations, collagen, cyclodextrins, derivatization, fast-growing chickens, fluorescent detection, hydroxyprolines, spaghetti meat, wooden breast,
• MeSH
• Cyclodextrins * chemistry   MeSH
• Electrophoresis, Capillary methods   MeSH
• Hydroxyproline * chemistry   analysis   MeSH
• Collagen * chemistry   MeSH
• Chickens MeSH
• Proline * chemistry   analysis   MeSH
• Protein Hydrolysates * chemistry   MeSH
• Stereoisomerism MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Cyclodextrins * MeSH
• Hydroxyproline * MeSH
• Collagen * MeSH
• Proline * MeSH
• Protein Hydrolysates * MeSH

Various studies have correlated the mechanical properties of the aortic wall with its biochemical parameters and inner structure. Very few studies have addressed correlations with the cohesive properties, which are crucial for understanding fracture phenomena such as aortic dissection, i.e. a life-threatening process. Aimed at filling this gap, we conducted a comprehensive biochemical and histological analysis of human aortas (the ascending and descending thoracic and infrarenal abdominal aorta) from 34 cadavers obtained post-mortem during regular autopsies. The pentosidine, hydroxyproline and calcium contents, calcium/phosphorus molar ratio, degree of atherosclerosis, area fraction of elastin, collagen type I and III, alpha smooth muscle actin, vasa vasorum, vasa vasorum density, aortic wall thickness, thicknesses of the adventitia, media and intima were determined and correlated with the delamination forces in the longitudinal and circumferential directions of the vessel as determined from identical cadavers. The majority of the parameters determined did not indicate significant correlation with age, except for the calcium content and collagen maturation (enzymatic crosslinking). The main results concern differences between enzymatic and non-enzymatic crosslinking and those caused by the presence of atherosclerosis. The enzymatic crosslinking of collagen increased with age and was accompanied by a decrease in the delamination strength, while non-enzymatic crosslinking tended to decrease with age and was accompanied by an increase in the delamination strength. As the rate of calcification increased, the presence of atherosclerosis led to the formation of calcium phosphate plaques with higher solubility than the tissue without or with only mild signs of atherosclerosis. STATEMENT OF SIGNIFICANCE: This study presents a detailed biochemical and histological analysis of human aortic samples (ascending thoracic aorta, descending thoracic aorta and infrarenal abdominal aorta) taken from 34 cadavers. The contribution of this scientific study lies in the detailed biochemical comparison of the enzymatic and non-enzymatic glycosylation-derived crosslinks of vascular tissues and their influence on the delamination strength of the human aorta since, to the best of our knowledge, no such comprehensive studies exist in the literature. A further benefit concerns the notification of the limitations of the various analytical methods applied; an important factor that must be taken into account in such studies.

• Keywords
• AGEs, Atherosclerosis, Calcification, Collagen maturation, Delamination, FTIR, Human aorta,
• MeSH
• Actins metabolism   MeSH
• Aorta * metabolism   MeSH
• Arginine analogs & derivatives   MeSH
• Atherosclerosis metabolism   pathology   MeSH
• Adult MeSH
• Elastin metabolism   MeSH
• Hydroxyproline metabolism   MeSH
• Middle Aged MeSH
• Humans MeSH
• Lysine analogs & derivatives   metabolism   MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Aging * physiology   MeSH
• Calcium metabolism   MeSH
• Vasa Vasorum metabolism   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Actins MeSH
• Arginine MeSH
• Elastin MeSH
• Hydroxyproline MeSH
• Lysine MeSH
• pentosidine MeSH Browser
• Calcium MeSH

Silver(I) complexes with proline and hydroxyproline were synthesized and structurally characterized and crystal structure analysis shows that the formulas of the compounds are {[Ag2(Pro)2(NO3)]NO3}n (AgPro) (Pro = L-proline) and {[Ag2(Hyp)2(NO3)]NO3}n (AgHyp) (Hyp = trans-4-hydroxy-L-proline). Both complexes crystallize in the monoclinic lattice with space group P21 with a carboxylate bidentate-bridging coordination mode of the organic ligands Pro and Hyp (with NH2+ and COO- groups in zwitterionic form). Both complexes have a distorted seesaw (C2v) geometry around one silver(I) ion with τ4 values of 58% (AgPro) and 51% (AgHyp). Moreover, the results of spectral and thermal analyses correlate with the structural ones. 1H and 13C NMR spectra confirm the complexes species' presence in the DMSO biological testing medium and their stability in the time range of the bioassays. In addition, molar conductivity measurements indicate complexes' behaviour like 1 : 1 electrolytes. Both complexes showed higher or the same antibacterial activity against Bacillus cereus, Pseudomonas aeruginosa and Staphylococcus aureus as AgNO3 (MIC = 0.063 mM) and higher than silver(I) sulfadiazine (AgSD) (MIC > 0.5 mM) against Pseudomonas aeruginosa. In addition, complex AgPro exerted a strong cytotoxic effect against the tested MDA-MB-231 and Jurkat cancer cell lines (IC50 values equal to 3.7 and 3.0 μM, respectively) compared with AgNO3 (IC50 = 6.1 (5.7) μM) and even significantly higher selectivity than cisplatin (cisPt) against MDA-MB-231 cancer cell lines (SI = 3.05 (AgPro); 1.16 (cisPt), SI - selectivity index). The binding constants and the number of binding sites (n) of AgPro and AgHyp complexes with bovine serum albumin (BSA) were determined at four different temperatures, and the zeta potential of BSA in the presence of silver(I) complexes was also measured. The in ovo method shows the safety of the topical and intravenous application of AgPro and AgHyp. Moreover, the complexes' bioavailability was verified by lipophilicity evaluation from the experimental and theoretical points of view.

• MeSH
• Anti-Bacterial Agents * pharmacology   chemistry   chemical synthesis   MeSH
• Hydroxyproline * chemistry   MeSH
• Coordination Complexes * chemistry   pharmacology   chemical synthesis   MeSH
• Humans MeSH
• Microbial Sensitivity Tests * MeSH
• Models, Molecular MeSH
• Molecular Structure MeSH
• Cell Line, Tumor MeSH
• Peptides chemistry   pharmacology   chemical synthesis   MeSH
• Cell Proliferation drug effects   MeSH
• Proline * chemistry   pharmacology   MeSH
• Antineoplastic Agents * pharmacology   chemistry   chemical synthesis   MeSH
• Pseudomonas aeruginosa drug effects   MeSH
• Drug Screening Assays, Antitumor MeSH
• Silver * chemistry   pharmacology   MeSH
• Cell Survival drug effects   MeSH
• Structure-Activity Relationship MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Anti-Bacterial Agents * MeSH
• Hydroxyproline * MeSH
• Coordination Complexes * MeSH
• Peptides MeSH
• Proline * MeSH
• Antineoplastic Agents * MeSH
• Silver * MeSH

Overcoming the skin barrier properties efficiently, temporarily, and safely for successful transdermal drug delivery remains a challenge. We synthesized three series of potential skin permeation enhancers derived from natural amino acid derivatives proline, 4-hydroxyproline, and pyrrolidone carboxylic acid, which is a component of natural moisturizing factor. Permeation studies using in vitro human skin identified dodecyl prolinates with N-acetyl, propionyl, and butyryl chains (Pro2, Pro3, and Pro4, respectively) as potent enhancers for model drugs theophylline and diclofenac. The proline derivatives were generally more active than 4-hydroxyprolines and pyrrolidone carboxylic acid derivatives. Pro2-4 had acceptable in vitro toxicities on 3T3 fibroblast and HaCaT cell lines with IC50 values in tens of µM. Infrared spectroscopy using the human stratum corneum revealed that these enhancers preferentially interacted with the skin barrier lipids and decreased the overall chain order without causing lipid extraction, while their effects on the stratum corneum protein structures were negligible. The impacts of Pro3 and Pro4 on an in vitro transepidermal water loss and skin electrical impedance were fully reversible. Thus, proline derivatives Pro3 and Pro4 have an advantageous combination of high enhancing potency, low cellular toxicity, and reversible action, which is important for their potential in vivo use as the skin barrier would quickly recover after the drug/enhancer administration is terminated.

• MeSH
• Administration, Cutaneous MeSH
• Hydroxyproline metabolism   MeSH
• Skin Absorption * MeSH
• Skin metabolism   MeSH
• Carboxylic Acids metabolism   MeSH
• Pharmaceutical Preparations metabolism   MeSH
• Humans MeSH
• Organic Chemicals metabolism   MeSH
• Permeability MeSH
• Proline * metabolism   MeSH
• Pyrrolidinones pharmacology   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Hydroxyproline MeSH
• Carboxylic Acids MeSH
• Pharmaceutical Preparations MeSH
• Organic Chemicals MeSH
• Proline * MeSH
• Pyrrolidinones MeSH

Ivabradine, the selective inhibitor of the If current in the sinoatrial node, exerts cardiovascular protection by its bradycardic effect and potentially pleiotropic actions. However, there is a shortage of data regarding ivabradine's interaction with the renin-angiotensin-aldosterone system (RAAS). This study investigated whether ivabradine is able to protect a hypertensive heart in the model of L-NAME-induced hypertension and to interfere with the RAAS. Four groups (n = 10/group) of adult male Wistar rats were treated as follows for four weeks: control, ivabradine (10 mg/kg/day), L-NAME (40 mg/kg/day), and L-NAME plus ivabradine. L-NAME administration increased systolic blood pressure (SBP) and left ventricular (LV) weight, enhanced hydroxyproline concentration in the LV, and deteriorated the systolic and diastolic LV function. Ivabradine reduced heart rate (HR) and SBP, and improved the LV function. The serum concentrations of angiotensin Ang 1⁻8 (Ang II), Ang 1⁻5, Ang 1⁻7, Ang 1⁻10, Ang 2⁻8, and Ang 3⁻8 were decreased in the L-NAME group and ivabradine did not modify them. The serum concentration of aldosterone and the aldosterone/Ang II ratio were enhanced by L-NAME and ivabradine reduced these changes. We conclude that ivabradine improved the LV function of the hypertensive heart in L-NAME-induced hypertension. The protective effect of ivabradine might have been associated with the reduction of the aldosterone level.

• Keywords
• L-NAME, aldosterone, angiotensin II, fibrosis, heart function, hypertension, ivabradine,
• MeSH
• Aldosterone blood   MeSH
• Angiotensins blood   MeSH
• Biomarkers MeSH
• Echocardiography MeSH
• Ventricular Function, Left drug effects   MeSH
• Hydroxyproline blood   metabolism   MeSH
• Hypertension diagnosis   etiology   metabolism   physiopathology   MeSH
• Ivabradine pharmacology   MeSH
• Cardiovascular Agents pharmacology   MeSH
• Collagen metabolism   MeSH
• Blood Pressure drug effects   MeSH
• Rats MeSH
• Disease Models, Animal MeSH
• NG-Nitroarginine Methyl Ester adverse effects   MeSH
• Renin-Angiotensin System drug effects   MeSH
• Renin blood   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Aldosterone MeSH
• Angiotensins MeSH
• Biomarkers MeSH
• Hydroxyproline MeSH
• Ivabradine MeSH
• Cardiovascular Agents MeSH
• Collagen MeSH
• NG-Nitroarginine Methyl Ester MeSH
• Renin MeSH

Impaired diabetic wound healing is an important current medical issue, mainly concerning patients recovering from complicated operations or patients with ulcers on their feet. The obese Zucker diabetic fatty rat, with a mutation in leptin receptors, may be a good choice for studying impaired wound healing. Male and female rats were fed a diabetogenic high-fat diet. Wound size changes of air-exposed excisional 2 cm circular wounds were measured until Day 10. Wound tissue was analyzed morphologically, histologically, and immunohistochemically. The hydroxyproline content in the granulation tissue (GT) was determined. mRNA expression was assayed by DNA-array analysis and real-time reverse transcription-polymerase chain reaction. Wound-size changes were retarded in diabetic rats and differed between the sexes. Diabetic wounds were characterized by impaired contraction, abundant crust production, increased inflammation, and pus formation. On Day 10, the GT contained a significantly increased amount of intercalated fat tissue and showed an irregular arrangement of GT and collagen fibers. Interestingly, the length of new epithelium was increased in diabetic wounds. The concentration of hydroxyproline in the GT of diabetic animals was significantly decreased to about one half when compared with the nondiabetic controls. The expression of interleukin-6, myeloperoxidase, stromelysin-1, and collagenase-3 was increased in the GT of diabetic rats on Day 10, while the expression of type I collagen and elastin was decreased. Taken together, Zucker diabetic fatty rats exhibited impairments in wound-size reduction, inflammatory response, tissue organization, and connective tissue turnover and are thus proposed as a new model for studying impaired repair.

• MeSH
• Diabetes Mellitus, Type 2 physiopathology   MeSH
• Elastin metabolism   MeSH
• Granulation Tissue metabolism   pathology   MeSH
• Suppuration pathology   MeSH
• Wound Healing physiology   MeSH
• Hydroxyproline metabolism   MeSH
• Interleukin-6 metabolism   MeSH
• Collagen Type I metabolism   MeSH
• Rats MeSH
• Skin injuries   pathology   MeSH
• Matrix Metalloproteinase 13 metabolism   MeSH
• Matrix Metalloproteinase 3 metabolism   MeSH
• Disease Models, Animal MeSH
• Obesity physiopathology   MeSH
• Peroxidase metabolism   MeSH
• Rats, Zucker MeSH
• Sex Factors MeSH
• Inflammation pathology   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Elastin MeSH
• Hydroxyproline MeSH
• Interleukin-6 MeSH
• Collagen Type I MeSH
• Matrix Metalloproteinase 13 MeSH
• Matrix Metalloproteinase 3 MeSH
• Peroxidase MeSH

The matrix metalloproteinases (MMPs) play a key role during cardiac remodeling. The aim of the study was to investigate the changes in collagenous proteins and MMPs in the model of non-ischemic, anthracycline-induced chronic cardiomyopathy in rabbits using both biochemical and histological approaches. The study was carried out in three groups of Chinchilla male rabbits: 1) daunorubicin (3 mg/kg, once weekly for 10 weeks), 2) control (saline in the same schedule), 3) daunorubicin with the cardioprotectant dexrazoxane (60 mg/kg, before each daunorubicin). Morphological changes in the myocardium of daunorubicin-treated animals were characterized by focal myocardial interstitial fibrosis of different intensity. The subsequent proliferation of the fibrotic tissue was marked by an increased content of both collagen types I and III, which resulted in their typical coexpression in the majority of bundles of fibers forming either smaller or larger scars. Biochemical analysis showed a significantly increased concentration of hydroxyproline, mainly in the pepsin-insoluble fraction of collagenous proteins, in the daunorubicin-treated group (1.42+/-0.12 mg/g) as compared with the control (1.03+/-0.04 mg/g) and dexrazoxane (1.07+/-0.07 mg/g) groups. Dexrazoxane co-administration remarkably reduced the cardiotoxic effects of daunorubicin to the extent comparable with the controls in all evaluated parameters. Using zymography, it was possible to detect only a gelatinolytic band corresponding to MMP-2 (MMP-9 activity was not detectable). However, no significant changes in MMP-2 activity were determined between individual groups. Immunohistochemical analysis revealed increased MMP-2 expression in both cardiomyocytes and fibroblasts. Thus, this study has revealed specific alterations in the collagen network in chronic anthracycline cardiotoxicity in relationship to the expression and activity of major MMPs.

• MeSH
• Chronic Disease MeSH
• Daunorubicin toxicity   MeSH
• Fibrosis MeSH
• Hydroxyproline metabolism   MeSH
• Cardiomyopathies * chemically induced   metabolism   prevention & control   MeSH
• Cardiovascular Agents pharmacology   MeSH
• Collagen metabolism   MeSH
• Rabbits MeSH
• Drug Interactions MeSH
• Matrix Metalloproteinase 2 metabolism   MeSH
• Matrix Metalloproteinase 9 metabolism   MeSH
• Disease Models, Animal MeSH
• Myocardium enzymology   pathology   MeSH
• Antibiotics, Antineoplastic toxicity   MeSH
• Razoxane pharmacology   MeSH
• Ventricular Remodeling physiology   MeSH
• Animals MeSH
• Check Tag
• Rabbits MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Daunorubicin MeSH
• Hydroxyproline MeSH
• Cardiovascular Agents MeSH
• Collagen MeSH
• Matrix Metalloproteinase 2 MeSH
• Matrix Metalloproteinase 9 MeSH
• Antibiotics, Antineoplastic MeSH
• Razoxane MeSH

BACKGROUND: Owing to the high correlation between the level of prolyl-4-hydroxyproline dipeptide in non-hydrolyzed urine and that of 4-hydroxyproline in hydrolyzed urine, we examined whether the dipeptide might function as a valuable marker of bone turnover. METHODS: Based on densitometric measurements, 68 postmenopausal women were divided into groups of non-osteopathic, osteopenic and osteoporotic subjects. The dipeptide and current urinary resorption markers were assayed in morning urine, the former using liquid chromatography, the others plus serum formation markers by means of immunoassay procedures. Together with the assay of basal levels, diet-related changes and healing effect of yearly alendronate therapy were assessed. RESULTS: Concentration levels in controls and osteoporotic subjects differed significantly; receiver operating characteristics yielded sensitivity of 0.743, specificity of 0.908, area under curve of 0.903, and cut-off of 10.2 micromol/mmol of creatinine. Spearman rank correlation showed the highest pair coefficient between the dipeptide and osteocalcin. Diet-related changes were not found. Following therapy, a significant decline occurred already within a trimester, whilst with the other resorption markers not until 6 months. CONCLUSIONS: The ease of the dipeptide assay in non-hydrolyzed urine surpasses that of hydroxyproline, and the results present the compound as a real competition to other commonly assessed markers in osteopathies.

• MeSH
• Alendronate therapeutic use   MeSH
• Biomarkers urine   MeSH
• Time Factors MeSH
• Dipeptides urine   MeSH
• Adult MeSH
• Hydrolysis MeSH
• Hydroxyproline urine   MeSH
• Bone and Bones pathology   physiopathology   MeSH
• Middle Aged MeSH
• Humans MeSH
• Osteoporosis, Postmenopausal drug therapy   physiopathology   urine   MeSH
• Bone Resorption urine   MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Alendronate MeSH
• Biomarkers MeSH
• Dipeptides MeSH
• Hydroxyproline MeSH
• prolyl-4-hydroxyproline MeSH Browser

A novel alpha- and beta-configured pyrrolidine nucleoside phosphonates in adenine series were synthesized from trans-4-hydroxy-L-proline as starting material. d(ApA) analogues were also prepared and studied with respect to their hybridization properties with polyU.

• MeSH
• Adenosine chemistry   MeSH
• Dinucleoside Phosphates chemistry   MeSH
• Hydroxyproline MeSH
• Indicators and Reagents MeSH
• Nucleotides chemical synthesis   chemistry   MeSH
• Oligonucleotides chemical synthesis   MeSH
• Organophosphonates chemistry   MeSH
• Poly U chemistry   MeSH
• Pyrrolidines chemistry   MeSH
• Stereoisomerism MeSH
• Binding Sites MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Adenosine MeSH
• Dinucleoside Phosphates MeSH
• Hydroxyproline MeSH
• Indicators and Reagents MeSH
• Nucleotides MeSH
• Oligonucleotides MeSH
• Organophosphonates MeSH
• Poly U MeSH
• Pyrrolidines MeSH

Angiotensin converting enzyme (ACE) inhibition has been reported to induce regression of hypertrophy in several models of hemodynamic pressure overload. The aim of the present study was to determine whether the ACE inhibitor captopril can reduce hypertrophy of the left ventricle induced by a chronic volume overload and modify collagen composition of the hypertrophied myocardium. Rabbits with four months lasting aortic insufficiency were divided into two groups: treated with captopril (20 mg/kg/day) for five weeks and treated with placebo. The respective control groups were represented by sham-operated animals. Aortic insufficiency induced a decrease of diastolic pressure, an increase of systolic and pulse pressure, hypertrophy of the left and right ventricle, and an increase of hydroxyproline content in the left ventricle without a change of hydroxyproline concentrations in either ventricle. Captopril treatment further enhanced pulse pressure by decreasing diastolic blood pressure. Hypertrophy of the left ventricle, hydroxyproline content and concentration in both ventricles were unaffected by captopril treatment. It is concluded that ACE inhibition did not reverse the left ventricular hypertrophy developed as a result of overload induced by aortic insufficiency. We suggest that mechanisms different from activation of the renin-angiotensin system may play a decisive role in the maintenance of hypertrophy in this particular model of volume hemodynamic overload.

• MeSH
• Antihypertensive Agents pharmacology   MeSH
• Aortic Valve Insufficiency complications   physiopathology   MeSH
• Chinchilla MeSH
• Hydroxyproline metabolism   MeSH
• Hypertrophy, Left Ventricular drug therapy   etiology   physiopathology   MeSH
• Angiotensin-Converting Enzyme Inhibitors pharmacology   MeSH
• Captopril pharmacology   MeSH
• Rabbits MeSH
• Blood Pressure physiology   MeSH
• Ventricular Remodeling physiology   MeSH
• Organ Size drug effects   MeSH
• Animals MeSH
• Check Tag
• Rabbits MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Antihypertensive Agents MeSH
• Hydroxyproline MeSH
• Angiotensin-Converting Enzyme Inhibitors MeSH
• Captopril MeSH