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PubMed1977

The effects of castration and testosterone administration on mast cells and hydroxyproline in rat skin.

In rat skin of both sexes, significantly higher concentrations of mast cells were observed in the genital area as compared with the skin of the back. The hydroxyproline (HPL) value in the preputial skin was half that in the dorsal skin. The influence of castration and the administration of testosterone on male rat skin mast cells and HPL were investigated. A possible relationship was pointed out between HPL value and the mast cell population of the skin.

Animals↗

PubMed1976

Myofibrillar ATPase, DNA and hydroxyproline content of human hypertrophied heart.

70 human hearts were studied less than 36 hours after death. The apex, and in some cases other parts of the myocardium were homogenized, DNA, hydroxyproline content, myofibrillar Ca2+ and Mg2+ ATPase were measured. In normal hearts the DNA and collagen content were 372 +/- 9 mg and 36 +/- 7 mg. Ca2+ and Mg2+ ATPase of the myofibrils prepared from these hearts have shown the same specific activity (35 +/- 5 and 34 +/- 6 nmol/min./mg) as those from fresh biopsies taken during open-chest surgery. The heart weight correlates with the DNA content (r= + 0.58 -p less than 0.01) and with the myofibrillar ATPase (r= - 0.33 - p less than 0.02) but not with the DNA concentration nor with the collagen content or concentration. The main result of this study was the presence of a negative correlation between the DNA content of the heart and the Mg2+ or Ca2+ myofibrillar ATPase (r= - 0.31, p less than 0.05 - r= - 0.45, p less than 0.01). This correlation was analysed with reference to the histological and biochemical studies published by several authors in human or experimental heart hypertrophy and it was suggested that in human heart hypertrophy the decrease of the myofibrillar or myosin ATPase is a direct consequence of the high degree of polyploidy of the muscular cells observed in this condition.

Adenosine Triphosphatases↗

PubMed1983

Clinical significance of serum hydroxyproline-containing peptides with special reference to hyproprotein.

Serum hydroxyproline-containing peptides were separated into three fractions, i.e. large protein, polypeptide and smaller peptides, by gel filtration on Sephadex G-200. The large protein was presumed to be the C1q subunit of the first component of complement by an immunological analysis. The polypeptide had an electrophoretic mobility corresponding to beta-globulin and its molecular weight was estimated between 35000 and 45000 by gel filtration analysis. The polypeptide might well be defined as hyproprotein. The molecular weight of smaller peptides was estimated between 1400 and 3000. As compared with the control value, hyproprotein levels were significantly increased in rheumatoid arthritis, systemic lupus erythematosus and chronic liver disease. C1q levels were slightly lowered in rheumatoid arthritis and systemic lupus erythematosus, and were slightly increased in chronic liver disease but were not significant. In all patient groups smaller peptides levels remained in the normal range. These results suggest that serum hyproprotein levels are raised in some fibroproliferative disorders, probably reflecting collagen metabolism.

Adolescent↗

PubMed1976

Synthesis of peptides and derivatives of 3- and 4- hydroxyproline.

Synthesis and properties are reported for a number of peptides and related derivatives of 3-hydroxy-L-proline and 4-hydroxyl-L-proline. These were made for several different purposes, namely, sythesis of N-acetyl-O-tosyl-4-hydroxy-L-proline amide as a model for chemical reduction of peptide-bound hydroxyproline, synthesis of tripeptides with the sequence glycyl-4-hydroxy-L-hydroxy-L-prolyl-X, synthesis of the naturally occurring sequence, glycyl-3-hydroxy-L-prolyl-4-hydroxy-L-proline, and monomers for polymerization to yield the sequence -glycyl-prolyl-4-hydroxy-L-prolyl-.

Amino Acids↗

PubMed1977

Urine hydroxyproline excretion--a marker of bone metastases in prostatic carcinoma.

24-hour urinary hydroxyproline excretion (THP), a marker of bone collagen metabolism, has been measured in 35 patients with carcinoma of the prostate. 21 patients had bone metastases diagnosed by bone scanning (99mTc MDP). All 9 patients with metastases studied before hormonal treatment and the majority of those on treatment had elevated levels. Patients with negative bone scans invariably had normal THP levels. Furthermore, THP reflected the presence of bone metastases more accurately than plasma alkaline or acid phosphatase. Serial THP levels altered predictably with symptomatic response to treatment. These results suggest that THP is more reliable than other markers of the presence and activity of bone metastases in response to treatment and may have been neglected in favour of more elaborate and costly X-ray and isotope investigations.

Acid Phosphatase↗

PubMed1979

Urinary hydroxyproline excretion in carcinoma of the prostate. A comparison of 4 different modes of assessment and its role as a marker.

Urinary hydroxyproline (HP) excretion has been estimated without prior dietary restriction in 33 patients with carcinoma of the prostate and expressed as either 24-h HP output or as the hydroxyproline/creatinine (HP/Cr) ratio in 24-h urine sample, an early morning urine sample or a spot urine sample. The early morning urine hydroxyproline/creatinine ratio (EMU HP/Cr) appears to be the most accurate and avoids the disadvantages of formal dietary restriction and prolonged urine collection. The rest is useful in monitoring the responses to treatment of a patient with bony metastatic disease and relapse of a patient when his tumour ceases to be hormone sensitive. Furthermore, changes in EMU HP/Cr occur earlier than changes in other clinical or investigative variables, giving the test predictive value.

Aged↗

PubMed1990

Acetylcholinesterase in cocultures of rat myotubes and spinal cord neurons: effects of collagenase and cis-hydroxyproline on molecular forms, intra- and extracellular distribution, and formation of patches at neuromuscular contacts.

Cultures of rat myotubes from 18-day-old embryos produce both globular (G) and asymmetric (A) forms of acetylcholinesterase (AChE; EC 3.1.1.7), mostly G1, G4, and A12 and a small proportion of A8. We show that all forms are partly intracellular and partly exposed to the extracellular medium; the A forms and their intra- and extracellular distribution are not modified when myotubes are grown in the presence of spinal cord neurons. In these cocultures, however, AChE patches may be detected immunohistochemically at sites of neuromuscular contacts. These patches represent a very minor proportion of AChE activity. We found that collagenase removes AChE patches but not the acetylcholine receptor clusters with which they coincide. This digestion specifically decreases the level of the A12 form. cis-Hydroxyproline, an inhibitor of collagen synthesis, reduces the level of G1 and blocks the synthesis of A forms.

Acetylcholinesterase↗

PubMed2006

Unusual extra space at the active site and high activity for acetylated hydroxyproline of prolyl aminopeptidase from Serratia marcescens.

The prolyl aminopeptidase complexes of Ala-TBODA [2-alanyl-5-tert-butyl-(1, 3, 4)-oxadiazole] and Sar-TBODA [2-sarcosyl-5-tert-butyl-(1, 3, 4)-oxadiazole] were analyzed by X-ray crystallography at 2.4 angstroms resolution. Frames of alanine and sarcosine residues were well superimposed on each other in the pyrrolidine ring of proline residue, suggesting that Ala and Sar are recognized as parts of this ring of proline residue by the presence of a hydrophobic proline pocket at the active site. Interestingly, there was an unusual extra space at the bottom of the hydrophobic pocket where proline residue is fixed in the prolyl aminopeptidase. Moreover, 4-acetyloxyproline-betaNA (4-acetyloxyproline beta-naphthylamide) was a better substrate than Pro-betaNA. Computer docking simulation well supports the idea that the 4-acetyloxyl group of the substrate fitted into that space. Alanine scanning mutagenesis of Phe139, Tyr149, Tyr150, Phe236, and Cys271, consisting of the hydrophobic pocket, revealed that all of these five residues are involved significantly in the formation of the hydrophobic proline pocket for the substrate. Tyr149 and Cys271 may be important for the extra space and may orient the acetyl derivative of hydroxyproline to a preferable position for hydrolysis. These findings imply that the efficient degradation of collagen fragment may be achieved through an acetylation process by the bacteria.

Acetylation↗

PubMed1991

Urinary 3-hydroxyproline excretion in Alport's syndrome: a non-invasive screening test?

Alport's syndrome is characterised by morphological and structural changes of the renal basement membranes. As the hydroxyproline content of isolated glomerular basement membranes is reduced in patients with Alport's syndrome, it is possible that the renal excretion of 3-hydroxproline (3-OHP), a key substrate of basement membrane collagen, may be altered in such patients. The urinary excretion of 3-OHP was determined by thin layer chromatography in 20 patients with Alport's syndrome, in healthy control subjects, and in patients with other renal diseases. These included patients with poststreptococcal glomerulonephritis, lower urinary tract infection, severe reflux nephropathy, lithium induced nephropathy, polycystic kidney disease, familiar benign haematuria, and renal graft rejection. Urinary excretion of 3-OHP was significantly higher in patients with Alport's syndrome compared with the patients with other renal diseases and the healthy control subjects. All other renal diseases investigated had 3-OHP values within the normal range. Urinary 3-OHP determination detected patients with Alport's syndrome with a high sensitivity (95.2%) and specificity (97.2%). We therefore suggest using urinary 3-OHP determinations as a simple non-invasive screening test for Alport's syndrome.

Adolescent↗

PubMed1975

Genetic control of susceptibility to hydroxyproline in Drosophila.

Hydroxyproline (OHP) is known to produce morphological abnormalities in susceptible Drosophila. In some, OHP prevents head eversion during pupation producing a cryptocephal (crc) phenocopy, others fail to fully stretch legs and wings producing a shortened distance between these appendages (LWD). In this paper the genetic basis of susceptibility to OHP is explored and compared to the control of susceptibility to glucosamine (GA) which also produces a crc phenocopy. The data suggest that genes providing resistance to the effects of GA are different from those conferring resistance to OHP. Furthermore, genes providing resistance to the crc effects of OHP appear to be different from those controlling resistance-to the LWD effects. Intrastrain gene coadaptation also seems to be important in resistance to OHP. The relevance of these results to the problem of the genetic control of developmental buffering is briefly discussed.

Animals↗

PubMed2005

Mechanisms mediating the biologic activity of synthetic proline, glycine, and hydroxyproline polypeptides in human neutrophils.

The accumulation of neutrophils at sites of tissue injury or infection is mediated by chemotactic factors released as part of the inflammatory process. Some of these factors are generated as a direct consequence of tissue injury or infection, including degradation fragments of connective tissue collagen and bacterial- or viral-derived peptides containing collagen-related structural motifs. In these studies, we examined biochemical mechanisms mediating the biologic activity of synthetic polypeptides consisting of repeated units of proline (Pro), glycine (Gly), and hydroxyproline (Hyp), major amino acids found within mammalian and bacterial collagens. We found that the peptides were chemoattractants for neutrophils. Moreover, their chemotactic potency was directly related to their size and composition. Thus, the pentameric peptides (Pro-Pro-Gly)5 and (Pro-Hyp-Gly)5 were more active in inducing chemotaxis than the corresponding decameric peptides (Pro-Pro-Gly)10 and (Pro-Hyp-Gly)10. In addition, the presence of Hyp in peptides reduced chemotactic activity. The synthetic peptides were also found to reduce neutrophil apoptosis. In contrast to chemotaxis, this activity was independent of peptide size or composition. The effects of the peptides on both chemotaxis and apoptosis were blocked by inhibitors of phosphatidylinositol 3-kinase (PI3-K) and p38 mitogen-activated protein (MAP) kinase. However, only (Pro-Pro-Gly)5 and (Pro-Pro-Gly)10 induced expression of PI3-K and phosphorylation of p38 MAP kinase, suggesting a potential mechanism underlying reduced chemotactic activity of Hyp-containing peptides. Although none of the synthetic peptides tested had any effect on intracellular calcium mobilization, each induced nuclear binding activity of the transcription factor NF-kappa B. These findings indicate that polymeric polypeptides containing Gly-X-Y collagen-related structural motifs promote inflammation by inducing chemotaxis and blocking apoptosis. However, distinct calcium-independent signaling pathways appear to be involved in these activities.

Apoptosis↗

PubMed1984

Plasma somatomedin activity and urinary hydroxyproline excretion during administration of human growth hormone in children with short stature. Short-term effects.

15 prepubertal children with short stature and varying peak growth hormone (GH) levels were given daily injections of increasing doses of human growth hormone (hGH) for consecutive periods of 7 days. Somatomedin activity (SM-act) and total urinary hydroxyproline excretion (THP) were determined in each period. In patients with a varying degree of GH deficiency, but without non-pituitary dependent abnormalities, there was a high correlation between basal SM-act and height velocity. Patients with catch-up growth had an unproportionally low SM-act and the Prader-Willi and transient Cushing patients had an unproportionally high one. All patients showed increases of SM-act and THP on hGH administration, but there was considerable variation of the shape of the curve and of the amplitude of the response. 3 1/2 days after the last injection, SM-act was back to basal level. There was a good correlation between weight-for-height and SM-act during the first two hGH doses, which fits the hypothesis of GH and insulin synergism on SM generation.

Adolescent↗

PubMed1984

Plasma somatomedin activity and urinary hydroxyproline excretion during administration of human growth hormone in children with short stature. Long-term effects and relation with short-term changes.

Growth velocity, somatomedin activity (SM-act) and total urinary hydroxyproline excretion (THP) were studied in 9 prepubertal short children on long-term human growth hormone (hGH) therapy, and compared to the short-term responses to hGH, described in the accompanying paper. Positive correlations were found between the short-term increases of either SM-act or THP and growth acceleration, but these were too weak to be used as a predictor. On a schedule of biweekly injections, pre-injection SM-act values were only slightly higher than pre-treatment values, but post-injection values were considerably higher and similar to the values obtained with comparable hGH doses in the short-term study. There was an excellent relationship of the increment of SM-act during chronic therapy over untreated values and the increases of growth velocity. During the first year on hGH therapy the mean SM-act, mean THP and growth acceleration showed strong correlations.

Adolescent↗

PubMed1976

Abnormal hydroxyproline polypeptides in the urine of patients with chronic uremia.

An abnormal peak of hydroxyproline polypeptides has been observed when the polypeptide fraction from the urines of patients with advanced chronic uremia was subjected to gel chromatography. This abnormality was apparently related to the degree of uremia and to the presence of uremic osteodystrophy. The abnormal peak was not observed in patients with high turnover bone disease without renal insufficiency and in patients with nephrotic syndrome and normal glomerular filtration rate.

Chromatography, Gel↗

PubMed1982

Hydroxyproline excretion in the detection of occult bone metastases from breast cancer.

When surgery fails to cure breast cancer it is due to disseminated micrometastases present at the time of operation. The measurement of urinary hydroxyproline (OHP) is a possible screening test for such metastases in bone. This study compared both a single and serial urinary OHP estimation with the axillary node status, the bone scan status and the subsequent clinical course. A single measurement did not correlate with the axillary node or bone scan status, neither was there a relationship with the subsequent clinical course. Serial OHP estimations, every 3 months for a year, increased the accuracy of the test such that node-positive patients had higher excretions than node-negative patients (p less than 0.05). Patients who subsequently died with bone metastases tended to have a higher excretion than those who remained disease free, although this did not reach statistical significance. No relationship existed between serial OHP estimations and bone scan status. We consider the measurement of urinary OHP to be insufficiently sensitive to detect bone micrometastases and it is only raised when a substantial amount of bone is involved.

Bone Neoplasms↗

PubMed1993

Cis-hydroxyproline inhibits adhesion, migration and proliferation of cultured rabbit keratocytes.

Recruitment of keratocytes into injured corneal stroma, and secretion of proteins including collagen in the cells are essential for wound healing of the corneal stroma. We examined the effect of a proline analog, cis-hydroxyproline, on the adhesion, migration and growth of rabbit keratocytes in vitro. This agent decreased the plating efficiency, migration and growth of the keratocytes in a dose-dependent manner. Reduction in these cellular activities may reflect altered functions of pericellular proteins such as collagen. Further studies are needed to determine which specific protein is involved.

Animals↗

PubMed1981

The effect of alpha-difluoromethyl-ornithine on tumor growth, acute phase reactants, beta-2-microglobulin and hydroxyproline in kidney and bladder carcinomas.

Multiple oral doses of alpha-difluoromethyl-ornithine (alpha-DFMO), 18-24 g/day for up to 2 months, were administered to 2 patients with invasive and metastatic carcinoma of the bladder and to 3 patients with metastatic renal cancer in an open study. The moderate antigrowth effect of alpha-DFMO in these patients was concluded from the results of serial kidney, liver and bone scintigrams, from the low frequency of a local recurrence of bladder carcinoma and from the survival rate of 4 of 5 patients after 12 months. Increased excretion of hydroxyproline and beta2-microglobulin were measured 1 month following alpha-DFMO treatment suggesting initial tumor necrosis and degradation. Treatment was poorly tolerated with gastrointestinal side effects (e.g. gastritis, vomiting, diarrhea) in all subjects, erythropenia in 2 subjects (associated with thrombocytopenia and leucopenia in 1 subject each), and audiovestibular symptoms in 2 patients. All side effects were reversible and normal function returned 2-4 months after stopping therapy.

17-Ketosteroids↗

PubMed1982

Myocardial hydroxyproline reduced by early administration of methylprednisolone or ibuprofen to rabbits with radiation-induced heart disease.

The ability of methylprednisolone (MP) and ibuprofen (IB) to reduce the severity of the late state of radiation-induced heart disease was assessed in 57 New Zealand white rabbits. Before and shortly after cardiac irradiation, 15 rabbits received i.v. MP, 30 mg/kg twice daily for 3 days, and 15 others received IB, 12.5 mg/kg twice daily for 2 days. No drug was administered to 14 irradiated rabbits, and neither irradiation nor drugs were administered to 13 rabbits that served as controls, All 15 rabbits treated with MP and 13 of the 15 treated with IB lived for 100 days. Only seven of the untreated, irradiated rabbits lived that long. Longevity of each treated group of rabbits was better (p less than 0.01 and 0.05) than that of the untreated, irradiated rabbits. Surviving rabbits were killed 100 days after irradiation. Pericarditis (p less than 0.05) and pericardial effusion (p less than 0.01) were less frequent in the treated, irradiated groups than in the untreated, irradiated rabbits. At least some rabbits in each irradiated group had microscopic evidence of myocardial fibrosis. The fibrosis was quantitated by determination of myocardial hydroxyproline concentrations (MHP). MHP concentration in the untreated, irradiated rabbits was greater than in those treated with MP (p less than 0.05) or IB (p less than 0.01) and in the untreated, unirradiated rabbits (p less than 0.01). Early administration of MP or IB retarded the development of myocardial fibrosis, pericarditis and pericardial effusion, and improved survival in this experimental model of radiation-induced heart disease.

Animals↗