Plasma hydroxyproline

During the initial studies of hypro-protein, the levels were compared in plasma and serum prepared simultaneously from the same normal 

Recent studies by Frey (FIO) have shown that similar values for 

Values fob Plasma Pbotbin Hydboxypboline Obtained by Vabious Pbocbddbes  

Whole human plasma after nitrous acid 7 16 15-19 

The level of free hydroxyproline in the blood is relatively constant in fasting subjects with normal renal function, 1.3-1.8 pg/ml of plasma in the author s study (Table 6), and 0.6-3.9 ig/ml of plasma in a larger group of normal subjects in a study of Baumann et al. (B3). The latter study does not mention the fasting state of their subjects, which may explain the wider variation. Laitinen et al. found the free plasma hydroxyproline to vary only between 0.6 and 1.5 p.g/ml in 95 subjects of various ages on a gelatin-free diet (LI). Kibrick et al. found 2.3 j ig/ml of free 

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F-13) HypeztiydroxypTolinemia. It is postulated that there is a defect in the oxidation of hydroxyproline. The symptoms may include mental retardation in addition to elevat plasma hydroxyproline. 

The experience with hydroxyproline measurement in tissue hydrolysates differs distinctly from that with urine and plasma hydroxyproline determinations. In tissues, methods have not been as carefully evaluated results have been much more variable both within and between the... 

In a newborn it is not uncommon to find increased levels of hydroxyproline. In older children the presence of an elevated plasma hydroxyproline level usually indicates the benign disorder hydroxyprolinemia. 

Masaoka, T., F. Akahori, S. Arai, and K. Sakaguchi. 1987. Effect of paraquat on plasma fibronectin, serum free hydroxyproline, serum ceruloplasmin and lung collagen content in monkeys. J. Toxicol. Sci. 12 329-340. 

Diet Fractional Renal Ca Reabsorption (%) Plasma Ultra-filtrable Ca (mg/100 ml) Urinary Cyclic AMP (ymoles/day) Urinary Hydroxyproline (mg/day)... 

Special assays (urine and plasma) lactate, orotidine, thiosulphate, carnitine, succinylacetone, hydroxyproline, urate, orotate, sialic acid, MPS, guanidino-acetate, HVA, pyroglutamate, 5H1AA, pipecolate, pyruvate, 3-hydroxybutyrate, phytanate, VLCFA, homocysteine, 7-dehydrocholesterol, phenylalanine ERNDIM 8 148... 

Age does not have a major influence on amino acid levels, with exception of the neonatal period. Premature babies may have underdeveloped hepatic and renal function, leading to increased tyrosine and methionine in their plasma as well as enhanced urinary losses of cystine, lysine, glycine, proline, hydroxyproline, and cystathionine. Taurine levels are generally increased in the first days of life. 

A 2-year randomized controlled study in 90 women compared the effects of oral tibolone doses of 1.25 mg/day and 2.5 mg/day on bone loss in the early postmenopausal period all took calcium 1000 mg/day. Vertebral and femoral bone density rose in both treated groups but fell in the control group, and bone turnover markers (urinary excretion of hydroxyproline/creatinine and plasma osteocalcin concentrations) were similarly affected favorably in the treated groups, as was the incidence of hot flushes/ flashes (5). Studies such as this still leave open the question of the advisability of continuing tibolone treatment over a longer period. While tibolone has indeed been shown to benefit mineral bone density, few data are available to show whether it lowers fracture incidence nor is it clear whether there is a link between tibolone and breast cancer (6). 

Human plasma NSTEACS 45 GC-MS Citric acid J. 4-Hydroxyproline J, Aspartic acid J, Fructose J, Lactate t Urea t Glucose t Valine t (11)... 

Kindt E, Gueneva-Boucheva K, Rekhter MD et at. (2003) Determination of hydroxyproline in plasma and tissue using electrospray mass spectrometry. J Pharm Biomed Anal 33 1081-1092... 

Vitamin C status is generally assessed by estimating the saturation of body reserves or measuring plasma and leukocyte concentrations of the vitamin. Urinary excretion of hydroxyproline-containing peptides is reduced in people with inadequate vitamin C status, but a number of other factors that affect bone and connective tissue turnover confound interpretation of the results (Bates, 1977). The ratio of deoxypyridinolineipyridinoline compounds derived from collagen cross-links provides a more useful index, but is potentially affected by copper status (Tsuchiya and Bates, 1997). 

Johnston, G, S Cartee, G. D., and Haskell, B, E. (1985). Effect of ascorbic acid nutritureOn protein-bound hydroxyproline in guinea pig plasma. /. Nulr. 115,1089-1093. 

Calcitonin is a useful marker for medullary carcinoma of the thyroid, which occurs both sporadically and as a dominantly inherited disease. In this type of tumor, the plasma concentration of calcitonin is 1-1000 mg/mL (normal concentration ranges from undetectable to 0.05 ng/mL). Also, urinary hydroxyproline excretion is decreased. Ectopic secretion of calcitonin also occurs from several types of pulmonary tumor in addition to other hormones. 

It is the purpose of this review to outline critically the methods available for hydroxyproline assay, and to summarize the information obtained by hydroxyproline determinations in urine, plasma (or serum), and the tissues, with emphasis on understanding the physiological and pathological setting in which these measurements have been made. No attempt will be made to discuss recent developments in the chemistry (H3, H4) or the biosynthesis (Ul) of collagen, since thorough reviews of these topics are available. 

Fio. 3. Absorption spectra of chromophores from 125 /jg of authentic hydroxyproline and protein hydrolysate of 1 ml of plasma. Chromophores were concentrated by adding 0.6 ml of water to the final ethanol-sulfuric acid-toluene-Ehrlich s reagent mixture of the colorimetric procedure, shaking the mixture, and separating the water-ethanol-acid phase the latter was then diluted to 3.0 ml with ethanol (L9). 

Unfortunately, many of the published studies do not mention the recent dietary intake of their subjects. This is important because of the exquisite sensitivity of plasma free hydroxyproline to the ingestion of even small amounts of collagen or gelatin. This has been well studied by Prockop and Keiser (P14) and Baumann (B3). It is recommended that at least a 12-hour fast precede the blood taking if free hydroxyproline is to be measured. 

Thus, the major abnormalities of plasma free hydroxyproline appear to result from (1) the ingestion of hydroxyproline, collagen, or gelatin in any form, and (2) an inability to metabolize hydroxyproline from either prematurity or an inborn error of metabolism. Theoretically, a... 

Marked elevations of plasma peptide hydroxyproline have been observed by Dubovsky et al. in chronic renal failure (D7). The highest levels were seen when uremia and severe bone disease occurred together. Removal of the parathyroids in four patients (three primary and one secondary hyperparathyroidism) was associated with return to normal levels when renal function was normal, and significant reduction when renal failure was present. It seems possible that plasma peptide hydroxyproline might be a rapidly changing and sensitive indicator of bone metabolism which could be studied even with renal impairment, a major obstacle to most current techniques in the diagnosis of hyperparathyroid states. 

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