A low-sulfated chondroitin sulfate in rat blood: An acidic glycosaminoglycan with a high metabolic rate

The rate of metabolism of low-sulfated chondroitin 4-sulfate, a predominant glycosaminoglycan in blood, has been studied by administering intraperitoneally radioactive hexosamine and/or sulfate to rats. The biological half-life of the material was estimated to be 10–12 h, suggesting that the metabolic process of blood low-sulfated chondroitin sulfate is different from that of glycosaminoglycans in the tissue.     

Active synthesis of glycosaminoglycans by liver parenchymal cells in primary culture

Rat liver parenchymal cells were evaluated after 2 days of primary culture for their ability to synthesize and accumulate heparan sulfate as the major component and low-sulfated chondroitin sulfate, dermatan sulfate, chondroitin sulfate and hyaluronic acid as the minor ones. The newly synthesized glycosaminoglycans secreted into the medium were different from those remaining with and/or on the cell layer. Low-sulfated chondroitin 4-sulfate, a major glycosaminoglycan in blood, was synthesized in the order of 320 μg/liver per day, more than 90% of which was secreted into the medium within 16 h and 40% of the glycan secreted was degraded during that time. On the other hand, heparan sulfate, the major glycosaminoglycan synthesized by the parenchymal cells, was mainly distributed in the cell layer. After 8 days of culture, the synthesis of glycosaminoglycans by the cells increased markedly, especially dermatan sulfate, chondroitin sulfate and hyaluronic acid.     

Urinary excretion of glycosaminoglycans and albumin in experimental diabetes mellitus

Diabetes mellitus was induced in one group of rats by a single injection of streptozotocin. The glycemia, the body weight, and the blood systolic pressure were measured every week, and the 24 h urine volume and urinary excretions of creatinine, albumin and glycosaminoglycans were measured every 2 weeks. At the end of the experiment (12 weeks) the weight and the glycosaminoglycan composition of the kidneys were determined. All the diabetic animals were hyperglycemic, hypertense, and did not gain weight during all the experimental period. Albuminuria appeared from the second week on. Rat urine was shown to contain heparan sulfate, chondroitin sulfate, and dermatan sulfate, and the glycosaminoglycan excretion decreased in all diabetic animals. The onset of the change in glyco-samino-glycan excretion rate was a very early event, appearing in the second week after diabetes induction. The main glycosaminoglycan found in normal rat kidney was heparan sulfate and, in contrast to the urine, the total kidney glycosaminoglycans increased in diabetic kidney, due to chondroitin sulfate and dermatan sulfate accumulation. The heparan sulfate concentration (per tissue dry weight) did not change. Our results suggest that quantification of urinary glycosaminoglycans may be a useful tool for the early diagnosis of diabetic nephropathy.     

Isolation and characterization of the sulfated glycosaminoglycans of the vitreous body

Ester sulfate containing glycosaminoglycans comprising approx. 3% of the total glycosaminoglycan content, have been isolated from protease-digested bovine vitreous body by stepwise fractionation on AG-1X2(Cl^?) and gel filtration on Bio-Gel P-300. Two heparan sulfate and two chondroitin-4-sulfate fractions were isolated in nearly pure form. The heparan sulfate fractions were undersulfated and contained the same relative proportions of N- and O-sulfate (1 : 2), although the total sulfate content differed by approx. 100%. No chondroitin-6-sulfate was present in the isolates, based on evidence obtained from chondroitin ABC lyase experiments.     

Altered expression of glycosaminoglycans in metastatic 13762NF rat mamma adenocarcinoma cells

A difference in the expression and metabolism of sulfated glycosaminoglycans between rat mammary tumor cells derived from a primary tumor and those from its metastatic lesions has been observed. Cells from the primary tumor possessed about equal quantities of chondroitin sulfate and heparan sulfate on their cell surfaces but released fourfold more chondroitin sulfate than heparan sulfate into their medium. In contrast, cells from distal metastatic lesions expressed approximately 5 times more heparan sulfate than chondroitin sulfate in both medium and cell surface fractions. This was observed to be the result of differential synthesis of the glycosaminoglycans and not of major structural alterations of the individual glycosaminoglycans. The degree of sulfation and size of heparan sulfate were similar for all cells examined. However, chondroitin sulfate, observed to be only chondroitin 4-sulfate, from the metastases-derived cells had a smaller average molecular weight on gel filtration chromatography and showed a decreased quantity of sulfated disaccharides upon degradation with chondroitin ABC lyase compared to the primary tumor derived cells. Major qualitative or quantitative alterations were not observed for hyaluronic acid among the various 13762NF cells. The metabolism of newly synthesized sulfated glycosaminoglycans was also different between cells from primary tumor and metastases. Cells from the primary tumor continued to accumulate glycosaminoglycans in their medium over a 72-h period, while the accumulation of sulfated glycosaminoglycans in the medium of metastases-derived cells showed a plateau after 18-24 h. A pulse-chase kinetics study demonstrated that both heparan sulfate and chondroitin sulfate were degraded by the metastases-derived cells, whereas the primary tumor derived cells degraded only heparan sulfate and degraded it at a slower rate.(ABSTRACT TRUNCATED AT 250 WORDS)     

Diversity in the degree of sulfation and chain length of the glycosaminoglycan moiety of urinary trypsin inhibitor isomers

Five isomers with different electric charge were fractionated from human urinary trypsin inhibitor (UTI) by anion exchange HPLC. Intact low-sulfated chondroitin 4-sulfate chains from the isomers were analyzed by HPLC and mass spectrometry. Unsaturated disaccharide composition analysis of the chondroitin sulfate chain revealed that the five isomers differ in the numbers of 4-sulfated disaccharide units. Intriguingly, we detected the presence of multiple novel isomers with different numbers of non-sulfated disaccharide units even in the same charge isomer fraction. Our results demonstrate that UTI can vary in terms of both the degree of sulfation and the length of the low-sulfated chondroitin 4-sulfate chain.     

The isolation, identification and characterization of sulfated glycosaminoglycans synthesized in vitro by human eosinophils

Human eosinophils were purified to greater than 92% using 16-30% metrizamide gradients, and these cells cultured for up to 72 h in vitro to label sulfated glycosaminoglycans. Over 90% of the sulfated glycosaminoglycan-containing material was extracted in 4 M guanidine HCl and had a hydrodynamic size similar to a glycosaminoglycan marker with an approximate average molecular weight of 60,000. Treatment of this salt-extracted 35S-labeled glycosaminoglycan-containing material with 0.5 M NaOH resulted in a change in mass to approx. 20,000 daltons, suggesting that the larger molecules were proteoglycans with side chains with an approximate molecular weight of 20,000. These salt extracted presumptive 35S-labeled proteoglycans were protease insensitive and behaved in a highly charged fashion on DEAE-cellulose. The composition of 35S-labeled glycosaminoglycans from human eosinophils as identified using selected polysaccharides was 70-81% chondroitin 4-sulfate, 9-12% chondroitin 6-sulfate, and 5-12% dermatan sulfate. The predominance of chondroitin 4-sulfate in human eosinophils is similar to the predominance of chondroitin 4-sulfate in human neutrophils and human platelets.     

Simultaneous detection of submicrogram quantities of hyaluronic acid and dermatan sulfate on agarose-gel by sequential staining with toluidine blue and Stains-All

A new discontinuous agarose-gel electrophoresis in 0.05 M HCl/0.04 M barium acetate combined with the highly sensitive visualization technique using toluidine blue/Stains-All has been developed for the simultaneous assaying of hyaluronic acid (HA) and dermatan sulfate (DS) with a detection limit at submicrogram level greater than other conventional procedures. Furthermore, this procedure also separates and reveals chondroitin sulfate (CS). The densitometric analysis of bands resulted in a linear response between 0.01 and 0.5 microg of glycosaminoglycans (GAGs) with correlation coefficients greater than approximately 0.94. Hyaluronic acid and dermatan sulfate extracted and purified from the abdominal skin of six rats were separated and quantified in comparison with the evaluation made by treatment of chondroitin ABC lyase and separation of Delta-disaccharides from hyaluronic acid (DeltadiHA) and dermatan sulfate/chondroitin sulfate (Deltadi4s and Deltadi6s) by HPLC. The total amount of rat skin polysaccharides (hyaluronic acid and dermatan sulfate) was 1.24+/-0.26 microg/mg of tissue by discontinuous agarose-gel electrophoresis and 1.20+/-0.33 microg/mg by HPLC with hyaluronic acid and dermatan sulfate percentages of 50.32+/-2.38 and 49.66+/-2.53, respectively. The analyses also confirmed that hyaluronic acid and dermatan sulfate are the main rat abdominal skin polysaccharides with chondroitin sulfate present in trace amounts. This new agarose-gel electrophoresis could be particularly useful in the study of the distribution of glycosaminoglycans in the skin from different body sites of animals and normal human subjects and may be of importance in understanding the changes that occur in the skin, especially the metabolism of extracellular matrix constituents, in connective tissue disorders.     

Characterization of a heparan sulfate and a peculiar chondroitin 4-sulfate proteoglycan from platelets. Inhibition of the aggregation process by platelet chondroitin sulfate proteoglycan

A high molecular weight chondroitin sulfate proteoglycan (Mr 240,000) is released from platelet surface during aggregation induced by several pharmacological agents. Some details on the structure of this compound are reported. beta-Elimination with alkali and borohydride produces chondroitin sulfate chains with a molecular weight of 40,000. The combined results indicate a proteoglycan molecule containing 5-6 chondroitin sulfate chains and a protein core rich in serine and glycine residues. Degradation with chondroitinase AC shows that a 4-sulfated disaccharide is the only disaccharide released from this chondroitin sulfate, characterizing it as a chondroitin 4-sulfate homopolymer. It is shown that this proteoglycan inhibits the aggregation of platelets induced by ADP. Analysis of the sulfated glycosaminoglycans not released during aggregation revealed the presence of a heparan sulfate in the platelets. Degradation by heparitinases I and II yielded the four disaccharide units of heparan sulfates: N,O-disulfated disaccharide, N-sulfated disaccharide, N-acetylated 6-sulfated disaccharide, and N-acetylated disaccharide. The possible role of the sulfated glycosaminoglycans on cell-cell interaction is discussed in view of the present findings.     

Sulfated glycosaminoglycans of cultured fibroblasts from guinea-pig embryo kidney

The sulfated glycosaminoglycan content of primary cultures of fibroblasts from guinea-pig embryo kidney is reported. A hybrid chondroitin sulfate comprises approx. 90% of these glycosaminoglycans from the cell coat. Changes in the proportion of labelled heparitin sulfate were also observed after successive subcultures. We postulate a possible correlation between the pattern of glycosaminoglycans and processes of cell selection and cell dedifferentiation in these cultures.     

Isolation and characterization of proteoglycans secreted by normal and malignant human mammary epithelial cells

The proteoglycans secreted by a malignant human breast cell line (MDA-MB-231) were compared with the corresponding proteoglycans from a normal human breast cell line (HBL-100). The physicochemical characteristics of these proteoglycans were established by hexosamine analysis, chemical and enzymatic degradations, and dissociative cesium chloride density gradient centrifugation, and by gel filtration before and after alkaline beta-elimination. Both cell lines secreted approximately 70% of the synthesized proteoglycans, which were composed of 20% heparan sulfate and 80% chondroitin sulfate proteoglycans. The MDA cell line secreted large hydrodynamic size (major) and small hydrodynamic size heparan sulfate proteoglycan. In contrast HBL cells secreted only one species having a hydrodynamic size intermediate to the above two. The chondroitin sulfate proteoglycans from MDA medium were slightly larger than the corresponding polymers from HBL medium. All proteoglycans except the small hydrodynamic size heparan sulfate proteoglycan from MDA medium were of high buoyant density. The proteoglycans of both cell lines contained significant proportions of disulfide-linked lower molecular weight components which were more pronounced in the proteoheparan sulfate polymers, particularly those from MDA medium, than in chondroitin sulfate proteoglycans. The glycosaminoglycans of heparan sulfate proteoglycans from MDA medium were more heterogeneous than those from HBL medium. The glycosaminoglycan chains of large hydrodynamic size heparan sulfate proteoglycans from MDA medium were larger in size than those from HBL medium while small hydrodynamic size heparan sulfate proteoglycans contained shorter glycosaminoglycan chains. In contrast to the glycosaminoglycans derived from chondroitin sulfate proteoglycans of both MDA and HBL medium were comparable in size. The heparan sulfate as well as chondroitin sulfate proteoglycans of both cell lines contained both neutral (di- and tetrasaccharides) and sialylated (tri- to hexasaccharides) O-linked oligosaccharides.     

Reduced Sulfation of Chondroitin Sulfate but Not Heparan Sulfate in Kidneys of Diabetic db/db Mice

Heparan sulfate proteoglycans are hypothesized to contribute to the filtration barrier in kidney glomeruli and the glycocalyx of endothelial cells. To investigate potential changes in proteoglycans in diabetic kidney, we isolated glycosaminoglycans from kidney cortex from healthy db/+ and diabetic db/db mice. Disaccharide analysis of chondroitin sulfate revealed a significant decrease in the 4-O-sulfated disaccharides (D0a4) from 65% to 40%, whereas 6-O-sulfated disaccharides (D0a6) were reduced from 11% to 6%, with a corresponding increase in unsulfated disaccharides. In contrast, no structural differences were observed in heparan sulfate. Furthermore, no difference was found in the molar amount of glycosaminoglycans, or in the ratio of hyaluronan/heparan sulfate/chondroitin sulfate. Immunohistochemical staining for the heparan sulfate proteoglycan perlecan was similar in both types of material but reduced staining of 4-O-sulfated chondroitin and dermatan was observed in kidney sections from diabetic mice. In support of this, using qRT-PCR, a 53.5% decrease in the expression level of Chst-11 (chondroitin 4-O sulfotransferase) was demonstrated in diabetic kidney. These results suggest that changes in the sulfation of chondroitin need to be addressed in future studies on proteoglycans and kidney function in diabetes.     

Pretreatment procedure for the microdetermination of chondroitin sulfate in plasma and urine

A new, simple, and rapid pretreatment method for the determination of chondroitin sulfate, dermatan sulfate, and hyaluronan from urine and blood plasma samples has been developed. Plasma proteins were first converted into small peptides by digestion using a nonspecific protease, actinase E, and the resulting small peptides were removed by centrifugal filtration. The retained, residual crude glycosaminoglycans, including chondroitin/dermatan sulfates and hyaluronan, were converted into unsaturated disaccharides through the action of chondroitin sulfate lyses. Next, these disaccharides were recovered and purified using centrifugal filtration together with DeltaDi-UA2S, added as an internal standard. The filtered disaccharide mixture was analyzed by HPLC with fluorometric postcolumn derivatization using 2-cyanoacetamide as a fluorogenic reagent. This method was applied to a pharmacokinetic study of chondroitin sulfate administered intravenously to mice. The half-life of the administered chondroitin sulfates, having molecular masses from 6 to 50 kDa, varied depending on their molecular sizes. This new method should be useful for studies on the metabolic fate of exogenously administered glycosaminoglycans in small experimental animals.     

Urinary excretion of glycosaminoglycans in patients with postmenopausal osteoporosis.

The organic bone matrix contains glycosaminoglycans (GAG) of which the precise function and importance in bone mineralisation are still unclear. We examined 85 persons--35 healthy women (25 premenopausal [preMP] mean aged 40.7 years; 10 menopausal [MP] mean aged 59.3 years) and 50 patients with postmenopausal osteoporosis [PMOP] at a mean age 60.4 years. The dynamic of urinary excretion of GAG was measured in 24-hour collected urine by precipitation with cetylpyridinum chloride and spectrophotometry at 560 nm, corrected for the level of excretion of creatinine. There was a significant increase in GAG excretion in patients with PMOP compared with healthy persons (8.25 mg/g and 9.53 mg/g vs 24.11 mg/g; p < 0.0001). A significant positive correlation was established between GAG and calcium urinary excretion and a negative one between GAG and serum estradiol levels. During the treatment with calcitonin the excretion of GAG was decreased which can be used for monitoring the changes of bone metabolism.     

Metabolism of sulfated glycosaminoglycans in cultivated bovine arterial cells. I. Characterization of different pools of sulfated glycosaminoglycans.

"Fibroblast-like" cells from the intimal layer of bovine aorta were grown in culture. The formation, composition, molecular weight and turnover rate of different pools of glycosaminoglycans were investigated in cultures incubated in the presence [35S]sulfate or [14C]glucosamine. The newly synthesized glycosaminoglycans are distributed into an extracellular pool (37 - 58%), a cell-membrane associated or pericellular pool (23 - 33%), and an intracellular pool (19 - 30%), each pool exhibiting a characteristic distribution pattern of chondroitin sulfate, dermatan sulfate, heparan sulfate and hyaluronate. The distribution pattern of the extracellular glycosaminoglycans resembles closely that found in bovine aorta. A small subfraction of the pericellular pool - tentatively named "undercellular" pool--has been characterized by its high heparan sulfate content. The intracellular and pericellular [35S]glycosaminoglycan pools reach a constant radioactivity after 8-12 h and 24 h, respectively, whereas the extracellular [35S]glycosaminoglycans are secreted into the medium at a linear rate over a period of at least 6 days. The intracellular glycosaminoglycans are mainly in the process of degradation, as indicated by their low molecular weight and by their half-life of 7 h, but intracellular dermatan sulfate is degraded more rapidly (half-life 4-5 h) than intracellular chondroitin sulfate and heparan sulfate (half-life 7-8 h). Glycosaminoglycans leave the pericellular pool with a half-life of 12-14 h by 2 different routes: about 60% disappear as macromolecules into the culture medium, and the remainder is pinocytosed and degraded to a large extent. Extracellular and at least a part of the pericellular glycosaminoglycans are proteoglycans. Even under dissociative conditions (4M guanidinium chloride) their hydrodynamic volume is sufficient for partial exclusion from Sepharose 4B gel. The existence of topographically distinct glycosaminoglycan pools with varying metabolic characteristics and differing accessibility for degradation requiresa reconsideration and a more reserved interpretation of results concerning the turnover rates of glycosaminoglycans as determined in arterial tissue.     

Characterization of sugar binding by osteoclast inhibitory lectin

Osteoclast inhibitory lectin (OCIL) is a membrane-bound C-type lectin that blocks osteoclast differentiation and, via binding to its cognate receptor NKRP1D, inhibits natural killer cell-mediated cytotoxicity. OCIL is a member of the natural killer cell receptor C-type lectin group that includes CD69 and NKRP1D. We investigated carbohydrate binding of soluble recombinant human and mouse OCIL in enzyme-linked immunosorbent assay-based assays. OCIL bound immobilized high molecular weight sulfated glycosaminoglycans, including fucoidan, lambda-carrageenan, and dextran sulfate, but not unsulfated dextran or sialated hyaluronic acid. Carbohydrate binding was Ca(2+)-independent. Binding of immobilized low molecular weight glycosaminoglycans, including chondroitin sulfate (A, B, and C forms) and heparin, was not observed. However, the soluble forms of these low molecular weight glycosaminoglycans competed for OCIL binding of immobilized fucoidan (as did soluble fucoidan, dextran sulfate, and lambda-carrageenan), indicating that OCIL does recognize these carbohydrates. Inhibition constants for chondroitin sulfate A and heparin binding were 380 and 5 nm, respectively. Immobilized and soluble monosaccharides did not bind OCIL. The presence of saturating levels of fucoidan, dextran sulfate, and lambda-carrageenan did not affect OCIL inhibition of osteoclast formation. The fucoidan-binding lectins Ulex europaeus agglutinin I and Anguilla anguilla agglutinin did not block osteoclast formation or affect the inhibitory action of OCIL. Although the osteoclast inhibitory action of OCIL is independent of sugar recognition, we have found that OCIL, a lectin widely distributed, but notably localized in bone, skin, and other connective tissues, binds a range of physiologically important glycosaminoglycans, and this property may modulate OCIL actions upon other cells.     

Proteoglycan and glycosaminoglycan synthesis by cultured rat mesangial cells

The synthesis of metabolically labeled proteoglycans and glycosaminoglycans from medium, cell layer and substrate attached material by rat glomerular mesangial cells in culture was characterized. The cellular localization of the labeled proteoglycans and glycosaminoglycans was determined by treating the cells with Flavobacterial heparinase. Of the total sulfated glycosaminoglycans, 33% were heparan sulfate; 55% of the cell layer material was heparan sulfate; 80% of sulfated proteins in the medium were chondroitin sulfate/dermatan sulfate. Putative glycosaminoglycan free chains of heparan sulfate and chondroitin sulfate were found in both the medium and cell layer; 95% of total proteoglycans and most (90%) of the putative heparan sulfate free chains were removed from the cell layer by the heparinase, whereas only 50% of the chondroitin sulfate and 25% of dermatan sulfate were removed. Large amounts of hyaluronic acid labeled with 3H glucosamine were found in the cell layer. In summary, approximately 60% of total sulfated glycoproteins was in the form of putative glycosaminoglycan free chains. Thus rat mesangial cells may synthesize large amounts of putative glycosaminoglycan free chains, which may have biological functions in the glomerulus independent of proteoglycans.     

Purification and characterization of protease-resistant secretory granule proteoglycans containing chondroitin sulfate di-B and heparin-like glycosaminoglycans from rat basophilic leukemia cells

Proteoglycans were extracted from nuclease-digested sonicates of 10(9) rat basophilic leukemia (RBL-1) cells by the addition of 0.1% Zwittergent 3-12 and 4 M guanidine hydrochloride and were purified by sequential CsCl density gradient ultracentrifugation, DE52 ion exchange chromatography, and Sepharose CL-6B gel filtration chromatography under dissociative conditions. Between 0.3 and 0.8 mg of purified proteoglycan was obtained from approximately 1 g initial dry weight of cells with a purification of 200-800-fold. The purified proteoglycans had a hydrodynamic size range of Mr 100,000-150,000 and were resistant to degradation by a molar excess of trypsin, alpha-chymotrypsin, Pronase, papain, chymopapain, collagenase, and elastase. Amino acid analysis of the peptide core revealed a preponderance of Gly (35.4%), Ser (22.5%), and Ala (9.5%). Approximately 70% of the glycosaminoglycan side chains of RBL-1 proteoglycans were digested by chondroitinase ABC and 27% were hydrolyzed by treatment with nitrous acid. Sephadex G-200 chromatography of glycosaminoglycans liberated from the intact molecule by beta-elimination demonstrated that both the nitrous acid-resistant (chondroitin sulfate) and the chondroitinase ABC-resistant (heparin/heparan sulfate) glycosaminoglycans were of approximately Mr 12,000. Analysis of the chondroitin sulfate disaccharides in different preparations by amino-cyano high performance liquid chromatography revealed that 9-29% were the unusual disulfated disaccharide chondroitin sulfate di-B (IdUA-2-SO4----GalNAc-4-SO4); the remainder were the monosulfated disaccharide GlcUA----GalNAc-4-SO4. Subpopulations of proteoglycans in one preparation were separated by anion exchange high performance liquid chromatography and were found to contain chondroitin sulfate glycosaminoglycans whose disulfated disaccharides ranged from 9-49%. However, no segregation of subpopulations without both chondroitin sulfate di-B and heparin/heparan sulfate glycosaminoglycans was achieved, suggesting that RBL-1 proteoglycans might be hybrids containing both classes of glycosaminoglycans. Sepharose CL-6B chromatography of RBL-1 proteoglycans digested with chondroitinase ABC revealed that less than 7% of the molecules in the digest chromatographed with the hydrodynamic size of undigested proteoglycans, suggesting that at most 7% of the proteoglycans lack chondroitin sulfate glycosaminoglycans.(ABSTRACT TRUNCATED AT 400 WORDS)     

Characterization of glycosaminoglycans stored in mucopolysaccharidosis III A: evidence for a generally occuring degradation of heparan sulfate by endoglycosidases.

The characterization of intracellularly stored glycosaminoglycans from organs of a patient suffering from mucopolysaccharidosis III A (Sanfilippo A disease) is described. Both heparan sulfate and galactosamine-containing glycosaminoglycans (chondroitin sulfate, dermatan sulfate) are accumulated in the liver, whereas in the other organs (spleen, kidney, heart, cerebrum, cerebellum) heparan sulfate is almost the only glycosaminoglycan stored. It is shown by [3H]NaBH4 reduction and subsequent identification of the 3H-labelled sugar alcohols that heparan sulfate is degraded in all organs by at least two endoglycosidases, an endoglucuronidase and an endoglucosaminidase, to fragments of low molecular weight (Mr approximately 2 000-6 600).     

Urinary excretion of immunoreactive prostaglandin F2 alpha in healthy children and adults

The 24-hours urinary excretion of immunoreactive prostaglandin F2 alpha (U-iPGF2 alpha) in normal children on a free diet was not significantly different in 30 boys (aged 3-15 years; geometric mean 589 ng/24 h) compared to 27 girls (aged 4-14 years; mean 473 ng/24 h). In both sexes this excretion rose with age until adolescence where it reached a plateau. In normal adults the men had significantly higher (p less than 0.001) excretions of U-iPGF2 alpha than the women; also body weight and urinary creatinine excretion were higher in men (p less than 0.001). In the children, as well as in the total population, U-iPGF2 alpha correlated best with body weight (r = 0.44 and r = 0.48 respectively; p less than 0.001) and the urinary creatinine excretion (r = 0.53 and 0.57 respectively; p less than 0.001); both body weight and urinary creatinine excretion are reflections of total body development. After the correction for urinary creatinine excretion or for body weight, the sex difference in the adult U-iPGF2 alpha totally disappeared.