Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Hydroxyproline”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 307 records · Page 17Linked to original sources
PubMedDate not supplied

Colorimetric determination of hydroxyproline as measure of collagen content in meat and meat products: NMKL collaborative study.

A colorimetric method for the determination of hydroxyproline as a measure of collagen in meat and meat products has been collaboratively studied in 18 laboratories. The method includes hydrolysis with sulfuric acid, oxidation with chloramine-T, and formation of a reddish purple complex with 4-dimethylaminobenzaldehyde. Five frozen and 3 freeze-dried samples were tested, ranging in content from 0.11 to 0.88% and from 0.39 to 4.0% hydroxyproline, respectively. The mean values of 2 identical samples were 0.245 and 0.251%. The average recovery from a spiked sample was 96.1%. The hydroxyproline content of a known sample (a mixture of 2 samples in the ratio 5:2) was calculated to 1.42%, which agrees well with the analytical result, 1.40%. In comparison with other collaborative studies, based on the ISO analytical method, the repeatability and reproducibility of this method agree well with the other results. This method was accepted as an official NMKL method by all national Committees, and has been adopted official first action by AOAC as an NMKL-AOAC method.

Animals↗
PubMedDate not supplied

Pulse labeling of hydroxyproline and leucine in reproductive tissues: a model for assessment of degree of reactivity.

A prospective study evaluating tissue reactivity by light microscopic and pulse labeling-autoradiographic techniques is presented. One uterine horn of a Sprague-Dawley rat model was subjected to transection and reanastomosis using microsurgical techniques (control). The opposite horn of each was also cross-sectioned with the application of an absorbable topical hemostatic agent (Avitene) and then reanastomosed. After closure of the abdomen, the animals were randomly assigned to groups according to the planned day of sacrifice (days 3, 7, 14, 21, or 28). Autoradiographic techniques utilizing [3H]hydroxyproline or [3H]leucine as well as light microscopy were employed to determine tissue reactivity. The results demonstrated an increase in stromal (P less than or equal to .05) and smooth muscle (P less than or equal to .01) reactivity with [3H]leucine labeling, and an increase in smooth muscle (P less than or equal to 0.05) reactivity with [3H]hydroxyproline in the Avitene-treated groups. It is concluded that pulse labeling with tritiated leucine and hydroxyproline is an effective method of objective analysis of tissue reactivity in reproductive organs.

Animals↗
PubMedDate not supplied

[Relation between infections during the pregnancy and the rate of hydroxyproline excretion in children with congenital chest deformities].

In a group of women, which had children with hereditary isolated and syndromal chest deformations, acute respiratory diseases, tonsillitis or influenza occurred during pregnancy in 42.9 +/- 6.6% and 53.8 +/- 13.8% of cases, respectively, whereas in the control group only 17.8 +/- +/- 7.2% of the women were impaired with identical infectious diseases during pregnancy (P less than 0.02 and P less than 0.05, respectively). Excretion of hydroxyproline was distinctly dissimilar in 22 children with isolated and in 13 children with syndromal chest deformations depending on presence or absence of the above-mentioned infections during pregnancy. Under conditions of these infections the higher level of total hydroxyproline excretion was noted as well as relatively lower content of bound hydroxyproline was detected in those peptides, which appear to be responsible for the content of newly synthesized collagen. The data obtained suggest that acute respiratory diseases, influenza, chronic and acute tonsillitis may impair collagen metabolism in children with hereditary chest deformations as well as that these infectious diseases occurred during pregnancy may increase the risk of the pathology development in the children.

Adolescent↗
PubMedDate not supplied

[Urinary excretion of hydroxyproline in patients with ischemic stroke].

Urinary excretion of total hydroxyproline being an indicator of the metabolism of systemic collagen was determined in 104 patients with ischaemic stroke and in 45 controls. The determinations were done by the method of Prockop-Udenfried in the urine of patients after 2 days on a non-collagen diet. Increased excretion of hydroxyproline was found in the subgroup of patients with high-grade paresis or paralysis, while in the subgroup with mild paresis these results were normal. The excretion of hydroxyproline in patients with severe paralysis increased during 3-60 days after stroke and then decreased in the period from 60 days to 5 years.

Adult↗
PubMed1987

[Behavior of hydroxyproline in the rat lung following exposure to surface dust and industrial ashes].

There was analysed, by means of biochemical examinations, the behaviour of hydroxyproline level in the lungs of experimental animals exposed to the action of soil dusts and electroenergetic ashes. 44 female white rats of Wistar strain were used in the experiment. The animals were administered intratracheally 0.2 ml dusts and electroenergetic ashes suspension. After decapitation, prepared material was taken from the left lung. Hydroxyproline determinations were performed according to Prokop's und Undenfried's method modified by Tomaszewski and Hanzlik. 9 months after the administration of the dusts, the contents of hydroxyproline slightly differed from the levels observed in control group.

Animals↗
PubMed1986

[The role of the urinary hydroxyproline level in the screening for collagen diseases].

Modifications in urinary hydroxyproline concentrations were studied in various collagen degradation diseases. A significant increase in hydroxyprolinuria was found in both men and women with Paget's disease in all age groups considered. Significant increases were found in men with the same pathologies. Rheumatoid arthritis also increased urinary hydroxyproline in both males and females. It therefore seems that bone tissue pathologies are reflected in the metabolism of hydroxyproline as are articular connective tissue pathology strictly related to it.

Adult↗
PubMed1986

Increase of gingival hydroxyproline and proline by improvement of ascorbic acid status in man.

The 4-hydroxyproline and proline content of periodontal tissue was measured in 24 adult volunteers with initially low and partially even deficient plasma vitamin C values, before and after peroral supplementation with 70 mg ascorbic acid daily for six weeks. The latter caused a statistically significant rise and normalization respectively of plasma ascorbic acid and simultaneously a statistically significant increase of the hydroxyproline and proline in periodontal tissue (p less than 0.01) but not before the plasma vitamin C level was above 0.9 mg/dl. The optimal plasma vitamin C level which was associated with the highest hydroxyproline and proline content in periodontal tissue ranged between 1.00-1.30 mg/dl corresponding to the total daily dietary ascorbic acid intake of about 100 mg.

Adult↗
PubMed1985

Liquid-chromatographic determination of total hydroxyproline in urine.

A reversed-phase "high-performance" liquid chromatographic assay for total hydroxyproline in urine is described. The urine samples are hydrolyzed overnight with acid, evaporated, solubilized, and derivatized with 4-dimethylaminoazobenzene-4'-sulfonyl chloride. The derivatives are chromatographed with a solvent gradient consisting of sodium acetate buffer and acetonitrile, the effluent being monitored at 436 nm. The useful lower limit of sensitivity for quantification is 13 pmol of hydroxyproline per 5-microL injection, corresponding to 33 mumol/L of urine. Either glutamine or cysteic acid is satisfactory as the internal standard. Peak heights and the amounts of hydroxyproline applied to the column are linearly related from 13.3 to 266 pmol. Mean analytical recovery was 83%. For four different concentrations the mean within-assay CV was 9.0% and the between-assay CV 12%. The normal reference interval found for 31 healthy adults was 31 to 177 mumol/24 h per square meter of body surface. We compared results for 10 samples from patients.

Adult↗
PubMed1979

Vitamin C deficiency in guinea pigs: changes in urinary excretion of proline, hydroxyproline and total amino nitrogen.

1. The age-related decrease in hydroxyproline : creatinine ratio in young guinea pigs was significantly smaller in vitamin C-deficient animals than in pair-fed controls. The same was true for proline : creatinine and total amino nitrogen : creatinine ratios, but hydroxyproline : total amino nitrogen and proline : total amino nitrogen ratios were not significantly affected by deficiency. 2. Although the proline : hydroxyproline ratio was unaffected in unfractionated urine, acute or chronic deficiency produced a small but significant increase in this ratio in collagenase digests of the acetone-insoluble fraction. 3. In scorbutic animals, therefore, collagen probably turns over more rapidly than in animals matched for inanition. Some at least, of this increase could represent the rapid turnover of underhydroxylated nascent collagen. Because it contains the degradation products from collagen from many tissues, differing widely in sensitivity to vitamin C status, the urine is unlikely, however, to provide a specific and sensitive functional index of vitamin C status.

Animals↗
PubMed1970

Total nitrogen and L-hydroxyproline content of adipose tissue from various sites in rats of different ages.

The total nitrogen and L-hydroxyproline concentrations of two intra-abdominal and two subcutaneous sites of adipose tissue were measured in male and female Wistar rats. At 100 g body weight the nitrogen concentration of intra-abdominal adipose tissue was slightly lower than that of subcutaneous adipose tissue. As age advanced beyond sexual maturity, the nitrogen content of intra-abdominal adipose tissue was steadily reduced, whereas that of subcutaneous tissue did not change. The L-hydroxyproline concentration of intra-abdominal adipose tissue was also lower than in subcutaneous adipose tissue. In male rats it rose in most adipose tissue sites when sexual maturity was reached, then fell with advancing age. In female rats the pattern of change was less consistent, but the l-hydroxyproline content of intra-abdominal adipose tissue was reduced as age increased.

Abdomen↗
PubMedDate not supplied

Urinary excretion of hydroxyproline and hydroxylysyl glycosides in adjuvant-induced arthritis.

The effect of adjuvant-induced arthritis on the urinary excretion of hydroxyproline and hydroxylysyl glycosides (glc-gal-hyl and gal-hyl) was investigated in male Sprague-Dawley rats up to 70 days after the injection of Freund's complete adjuvant. In comparison with control animals the total urinary hydroxyproline is significantly increased in the arthritic rats at one day after injection, returns to normal level at one week and is further significantly increased between the 2nd to 7th week. The excretion of total glycosides in urine parallels the excretion of total hydroxyproline. However, the low ratio of glc-gal-hyl/gal-hyl provides circumstantial evidence in favour of the hypothesis of bone collagen degradation in the acute stage of adjuvant-induced arthritis in rats (between 2 and 3 weeks), while high absolute values but normal ratios of glc-gal-hyl/gal-hyl suggest degradation of both bone and skin collagen in equal amounts between the 4th and 7th week. No significant differences are found between control and arthritic groups in the later part of the experiment.

Animals↗
PubMed1981

[Studies on prolyl hydroxylase activity, hydroxyproline content and solubility of collagen in the human uterus during pregnancy, delivery and postpartum involution (author's transl)].

Prolyl hydroxylase activity, hydroxyproline content and solubility of collagen in the human pregnant and post-partum uterus were studied. The results were as follows: 1. Prolyl hydroxylase activity in the uterine cervix was slightly elevated during pregnancy, and the highest level was observed on the 4th day post-partum. On the other hand, in the uterine body the highest activity was observed immediately after delivery. 2. Hydroxyproline content in the pregnant uterine cervix was slightly less than that of nonpregnant control and the lowest level was observed immediately after delivery, but on the 4th day post-partum it increased slightly. In the uterine body, there were no remarkable changes in content during pregnancy, but immediately after delivery it decreased remarkably. 3. Pepsin-soluble collagen in the uterine cervix increased significantly from an early pregnancy to immediately after delivery compared with nonpregnant control, but on the 4th day post-partum it decreased significantly compared with that immediately after delivery. In the uterine body, no significant changes in solubility were observed throughout pregnancy. 4. Comparing these data obtained on the cervix and the body at different stages of nonpregnancy, pregnancy and post-partum, enzyme activities in the body were always higher. Hydroxyproline content in the body of nonpregnant uterus showed a lower value than that in the cervix, but no remarkable differences were found between the cervix and the body throughout pregnancy and immediately after delivery. The significant decrease in pepsin-soluble collagen in the body was observed immediately after delivery.

Collagen↗
PubMed1982

[Effects of propranolol and indomethacin upon urinary hydroxyproline in hyperthyroid patients (author's transl)].

Hydroxyproline excretion was increased by hyperthyroid patients. This increase was related to thyroid hormone levels. Propranolol administration induced a decrease in hydroxyproline excretion and in immunoreactive triiodothyronine. Indometacin administration induced a decrease in urinary excretion of prostaglandins but had no effect on hydroxyproline excretion. These data suggest that the increased bone resorption of hyperthyroidism may involve a catecholamine beta receptor-dependent mechanism and is probably independent of prostaglandins.

Adult↗
PubMed1981

[Serum hydroxyproline parameter of collagen metabolism (author's transl)].

The serum hydroxyproline level enables a clinical assessment to be made of bone metabolism. A clinical-chemical method, which is described in detail, was applied in 50 control persons as well as in 76 patients with diseases of bones and/or joints. This method, which is a modification of the standard ion-exchange method of Goverde and Veenkamp for the determination of free hydroxyproline in serum, is readily applicable to mass routine laboratory usage and may be repeated ad libitum, thereby facilitating control follow-up of therapeutic response. The mean value of serum free hydroxyproline in the normal control group was 11.9 mu mol/1 (range: 6.86 to 16 mu mol/1), i.e. 1.56 mg/1 (range: 0.9 to 21 mg/1). The upper limit of normal values was calculated to be 15.5 mu mol/1 (2.0 mg/1), allowing a clear-cut differentiation from pathologically raised levels above this value.

Adult↗
PubMed1981

[Urinary excretion of hydroxyproline in chronic obstructive bronchitis].

The establishment of the hydroxyproline excretion in the urine is done in a normal collective of healthy persons, 68 patients with bronchitis in the compensated and 25 patients with bronchitis in the decompensated stage. The comparison of the mean value by means of the Scheffé-test results in significant differences between the normal collective and the patients with bronchitis in the stage of decompensation. Though an increase of the hydroxyproline excretion in the urine in chronic bronchitis with formation of an emphysema is a prognostically unfavourable prediction, this method cannot be recommended for a broader application in practice. The main reason for this is the danger of an incorrect interpretation on account of insufficient knowledge on the origin of hydroxyproline.

Bronchitis↗
PubMed1980

Urinary hydroxyproline excretion in myelofibrosis.

Urinary hydroxyproline measurements were performed in a group of health volunteers as well as patients with cancer and myelofibrosis. Patients in whom there was no metastatic involvement of bone marrow excreted an amount of hydroxyproline not different from that of the control group. Those who had marrow metastasis produced elevated levels of hydroxyproline; the highest excretions were observed when marrow fibrosis was associated with metastasis. These results contrasted with those observed in agnogenic myeloid metaplasia patients whose excretions were equivalent to the control group. The result suggests differences in the pathogenesis of myelofibrosis and a technique potentially useful for distinguishing between patients who may otherwise be diagnostic problems.

Bone Neoplasms↗
PubMed1980

Relationships among anthropometric indices of growth and creatinine and hydroxyproline excretion in preadolescent black and white girls.

Relationships among anthropometric indices of growth and creatinine and hydroxyproline excretion were studied over a 2-year longitudinal period in 124 preadolescent girls. Four groups of girls were selected: low-income white (LIW), middle-income white (MIW), low-income black (LIB) and middle-income black (MIB). Changes in body height, weight, subcapsular skinfold, bone density of the phalanx and bone mineral of the radius and ulna were used as indices of growth in relation to creatinine and hydroxyproline excretion. There were no significant differences in subcapsular skinfold among the groups. Bone density of the phalanx and bone mineral of the radius and ulna were significantly greater in blacks than whites at each age. Mean values for urinary creatinine concentration ranged from 0.115 to 0.209 g/dl from 9 to 11 years of age and tended to be greater for the middle-income than the low-income girls. Urinary hydroxyproline (g)/creatinine (g) ranged from 0.072 at 9 to 0.128 at 11 years of age with no significant differences between groups. All measurements showed significant increases with age. Significant positive correlations were seen among several indices in both racial groups and are discussed. INDEX WORDS: Growth, height/weight, hydroxyproline/creatinine excretion, race-income groups, subscapular skinfold, bone density, bone mineral content, preadolescent girls.

Black People↗
PubMedDate not supplied

Hydroxyproline centiles for normal adolescent boys and girls.

Centiles for 24 hour urinary total hydroxyproline are useful in monitoring growth and the effect of treatment in children with orthopedic diseases such as scoliosis, where growth is difficult to measure by anthropometric means. The centiles have been calculated from the data of a 5 year longitudinal study on 100 normal adolescent schoolchildren. Hydroxyproline estimations and assessments of growth were done 3 times a year. The rate of growth (height velocity) can be correlated with hydroxyproline levels found in adolescents.

Adolescent↗