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.     

The influence of coal ashes and soil dust on the activity of two selected hydrolytic enzymes in the liver of laboratory animals

The effect of a single intratracheal application of the electroenergetic ashes and the soil dust on the liver cell was studied by means of the histoenzymatic methods for the determination of the activities of chosen hydrolases (AcP, E.C. 3.1.3.2. and ATP, E.C. 3.6.1.). The degree of the histochemical changes in hepatocytes depended on the kind of the applied dust and the trace elements' content in it. The activity's increase of the acid phosphatase and ATP-ase in each experimental group was observed, especially in the preparations collected from the animals were given the electroenergetic ashes.     

Experimental comparative studies of the reactibility of lung tissue to intratracheally introduced ash produced by power plants

There was analysed the behaviour of the pulmonary tissue in white Wistar female rats exposed to a single effect of electroenergetic ashes from a few Polish power stations, hasting plants and electrohasting plants. The animals received a single 0.6 ml dose of the ashes in suspension of physiologic fluid intratracheally; 3 and 6 months after the experiment, the animals were decapitated and material for examinations was collected. Grains of used ashes were then assessed under the scanning electron microscope. Segments were stained with hematoxyline and cosine and by Masson's method. All the ashes caused inflammatory infiltrations, granulomas containing grains of the examined ash, fibrosis, thickening of interalveolar septa, atelectasis, and emphysema. The experiment resulted in a disturbance of biological balance of pulmonary connective tissue (stroma) due to the action of the ashes.     

Toxicological effects of an organophosphorus pesticide (dimethoate) on urinary collagen metabolites in normal and high protein diets fed female albino rats

The effect of an organophosphorus pesticide (dimethoate) on the urinary excretion of hydroxyproline (total, nondialysable, dialysable and free fractions) and hydroxylysylglycosides, glucosylgalactosyl hydroxylysine and galactosehydroxylysine was investigated in two groups of female albino rats fed with normal and high protein diets. In comparison to controls, dimethoate treated animals were found to excrete significantly decreased amounts of urinary hydroxyproline fractions from 7th day onwards. The excretion of total hydroxylysylglycoside in urine parallels the excretion of hydroxyproline. The urinary output of both glu-gal-hyl and gal-hyl was also appreciably lower from dimethoate treated animals. The normal ratio of glu-gal-hyl and gal-hyl found in the urine of dimethoate treated animals was discussed in light of decreased turn over of collagen in both bone and skin. The effect of dimethoate in rats fed with high protein diet was comparatively less than those fed with normal diet.     

Studies in vivo on the biosynthesis of collagen and elastin in ascorbic acid-deficient guinea pigs. Evidence for the formation and degradation of a partially hydroxylated collagen

1. After the administration of l-[G-(3)H]proline to guinea pigs deprived of ascorbic acid for increasing periods of time, the specific radioactivities of proline and hydroxyproline in skin collagen and aortic elastin were determined at various time-intervals after administration of the labelled compound with a view to studying the formation and degradation of collagen and elastin both deficient in hydroxyproline. 2. As judged from the incorporation of radioactivity into elastin proline, elastin synthesis was not decreased in the ascorbic acid-deficient animals. There was however, a rapid decline in the specific radioactivity of elastin hydroxyproline. The proline/hydroxyproline specific-radioactivity ratio was approx. 1.5:1 after 6 days and 20:1 after 12 days of ascorbic acid deprivation, in contrast with the ratio of 1:1 in controls. The results suggested that the effect of ascorbic acid deficiency on elastin biosynthesis could be regarded as simply an elimination of hydroxylation of elastin proline with the formation and retention of a polymer increasingly deficient in hydroxyproline. 3. Collagen proline and hydroxyproline specific radioactivities were derived from material that was soluble in hot trichloroacetic acid, non-diffusible and collagenase-degradable. In contrast with elastin, there was a rapid decline in the specific radioactivity of proline as well as hydroxyproline in collagen from the ascorbic acid-deficient animals. However, the proline/hydroxyproline specific-radioactivity ratio in all samples from scorbutic animals was consistently slightly above 1:1. The results suggest the appearance in place of collagen, but in rapidly diminishing amounts, of a partially hydroxylated collagen in which the degree of hydroxylation may be decreased only by approx. 10%. 4. Incorporation of radioactivity into the diffusible hydroxyproline in skin remained relatively high despite the rapid decline in the incorporation of radioactivity into collagen. This observation is interpreted as indicative of an increasing degree of degradation of partially hydroxylated collagen to diffusible peptides. An alternative explanation might be that partially hydroxylated peptides are released to an increasing extent from ribosomes before they attain a length at least sufficient to render them non-diffusible. In either case it implies the accumulation in scurvy of low-molecular-weight peptides enriched in proline and deficient in hydroxyproline and could explain the failure to accumulate a high-molecular-weight collagen deficient in hydroxyproline. 5. It is thought, however, that, in addition, an inhibition of ribosomal amino acid incorporation leading to decreased synthesis of partially hydroxylated collagen may also occur, perhaps secondarily to impaired hydroxylation.     

Excretion of urinary hydroxyproline in correlation with severity of induced osteomyelitis in rabbits.

Osteomyelitis was induced artificially by injecting Staphylococcus aureus culture in the tibiae of young rabbits. Weekly estimations of hydroxyproline in urine were done for six weeks. It was found that the osteomyelitic rabbits excreted more hydroxyproline (about 96%) two weeks after the infection in comparison to the control animals and it continued to be very high (about 138%) six weeks after the infection. The results indicate that urinary hydroxyproline reflects degradation of collagen fibers in the bone, and may be an indicator of the severity of the disease.     

Synthesis and degradation of collagens in skin of healthy and protein-malnourished rats in vivo, studied by 18O2 labelling.

To explore the effects of growth retardation, caused by restricted protein intake, on collagen turnover in the whole skin, Sprague-Dawley rats (n = 20) were labelled with 18O2 and fed on either an adequate (18%) or a low (3%) lactalbumin diet. Skin biopsies were obtained at intervals during the following 6 months. Independent groups of animals (n = 186) were used to determine the size of the 0.5 M-acetic acid-soluble and -insoluble collagen pools in the entire skin of healthy and malnourished rats. Collagen was estimated by measurement of hydroxyproline. Soluble-collagen synthesis rates were equivalent to 99 +/- 8 mumol of hydroxyproline/day in healthy animals and 11 +/- 2 mumol/day in malnourished rats. Insoluble-collagen synthesis rates were 32 and 5 mumol of hydroxyproline/day in the healthy and protein-depleted rats respectively. The degradation of soluble collagen amounted to 37 +/- 8 and 6 +/- 2 mumol of hydroxyproline/day in the healthy and malnourished groups respectively. Efflux of collagen from the soluble collagen, defined as the sum of the rate of soluble collagen that is degraded plus that which matures into insoluble collagen, was 70 +/- 8 and 11 +/- 2 mumol of hydroxyproline/day in the healthy and malnourished groups respectively. Insoluble collagen was not degraded in either group. The fraction of soluble collagen leaving the pool that was converted into insoluble collagen was 0.46 in both diet groups. It is concluded that the turnover of soluble collagen is markedly decreased with malnutrition, but degradation and conversion into insoluble collagen account for the same proportions of efflux from the soluble-collagen pool as in rapidly growing rats.     

Reduction of chronic hypoxic pulmonary hypertension in the rat by beta-aminopropionitrile

We administered antifibrotic agent beta-aminopropionitrile (BAPN) to rats exposed to 10% O2-90% N2 for 3 wk to prevent excess vascular collagen accumulation. Groups of Sprague-Dawley rats studied were air breathing, hypoxic, and hypoxic treated with BAPN, 150 mg/kg twice daily intraperitoneally. After the 3-wk period, we measured mean right ventricular pressure (RVP), the ratio of weight of right ventricle to left ventricle plus septum (RV/LV + S), and hydroxyproline content of the main pulmonary artery (PA) trunk. Hypoxia increased RVP from 14 to 29 mmHg; RVP was 21 mmHg in hypoxic BAPN-treated animals. Hypoxia increased the RV/LV + S ratio from 0.28 to 0.41; the ratio was 0.32 in hypoxic BAPN-treated animals. Hypoxia increased PA hydroxyproline from 20 to 239 micrograms/artery; hydroxyproline was 179 micrograms/artery in hypoxic BAPN-treated animals. Thus BAPN prevented pulmonary hypertension, right ventricular hypertrophy, and excess vascular collagen produced by hypoxia. We conclude that vascular collagen contributes to the maintenance of chronic hypoxic pulmonary hypertension.     

Influence of bleomycin on the metabolism of dermal collagen in albino rats

The metabolism of collagen in male rats by treatment with bleomycin was studied following the injection of [3H]proline and the determination of specific and total activity of [3H]hydroxyproline in skin collagen fractions and urine. In the case of the bleomycin-treated animals, there was found to be an increase in the neutral salt soluble collagen content with no change in insoluble collagen content as compared to the control group. The specific and total radioactivity of [3H]hydroxyproline in soluble and insoluble collagen fractions was also increased. Examination of [3H]hydroxyproline activity in soluble and insoluble collagen showed that the conversion of soluble to insoluble collagen was improved by the bleomycin-treated group. It was found that this was accompanied by a decrease in urinary excretion of total hydroxyproline and [3H]hydroxyproline during the first 12 hr after the administration of [3H]proline. Therefore, the results of the present investigation clearly indicate that the maturation of soluble to insoluble collagen is promoted and accompanied by a decrease in the catabolism of soluble collagen in the bleomycin-treated animals. In addition, administration of bleomycin increased the synthesis of collagen.     

Studies in vivo on the biosynthesis of collagen and elastin in ascorbic acid-deficient guinea pigs

1. After the administration of labelled proline to guinea pigs deprived of ascorbic acid for 15 days, the dorsal skin was examined 5 days later in an attempt to detect the presence of hydroxyproline-deficient collagen (protocollagen). The extent of incorporation of proline into skin collagens indicated a severe impairment of collagen synthesis. 2. A comparison of proline and hydroxyproline specific radioactivities in diffusible peptides obtained by treatment with collagenase of either purified skin collagens or direct hot-trichloroacetic acid extracts of skin failed to indicate the presence of protocollagen. Possible reasons for this are discussed. 3. The incorporation results did not indicate an inability of normal collagen, i.e. collagen hydroxylated to the normal degree, to cross-link in scurvy. 4. Incorporation of labelled proline into aortic elastin isolated from the same animals did not indicate a decrease in elastin biosynthesis in ascorbic acid deficiency, beyond that attributable to the inanition accompanying the vitamin deficiency. The proline/hydroxyproline specific-radioactivity ratio in elastin from scorbutic guinea pigs was about 6:1 in contrast with the 1:1 ratio in control groups. It is concluded that the formation of elastin hydroxyproline was ascorbate-dependent and that a hydroxyproline-deficient elastin is formed and retained in scurvy. The formation of desmosines was unimpaired in scorbutic animals. 5. Studies with chick embryos confirmed the formation of elastin hydroxyproline from free proline. Incorporation of free hydroxyproline into elastin hydroxyproline was negligible. 6. Digestion of solubilized samples with collagenase indicated that the hydroxyproline in guinea-pig aortic elastin preparations was not derived from contamination by collagen. It is suggested that most if not all of the hydroxyproline in the guinea pig elastin preparations investigated can be considered an integral part of the elastin molecule.     

Hydrochlorothiazide lowers urinary hydroxyproline in parathyroidectomized rats

This study was undertaken to examine the effects of hydrochlorothiazide treatment on urinary hydroxyproline excretion in parathyroidectomized rats. Urinary hydroxyproline (mumol/24 hr) fell significantly in thiazide-treated rats compared with control animals (5.66 +/- 0.37 versus 7.30 +/- 0.6, P less than 0.05, means +/- SEM). This fall in hydroxyproline excretion occurred without a decrease in glomerular filtration rate. It is concluded that the ability of thiazide diuretics to reduce urinary hydroxyproline excretion is not dependent upon suppression of parathyroid hormone-mediated bone turnover.     

Wound healing potential of ethanolic extract of Kalanchoe pinnata Lam. leaf--a preliminary study

The extract of K. pinnata was evaluated for its wound healing activity by using excision wound model in rats. On day 11, animals treated with the ethanolic leaf extract exhibited 86.33% reduction in the wound area, compared to petroleum jelly treated control (69.36%) and the mupirocin treated standard (85.49%). The hydroxyproline content of extract treated animals was higher, as compared to control and the standard groups. Histological analysis was also consistent with the proposal that K. pinnata leaf extract exhibits significant wound healing potential. The increased rate of wound contraction and hydroxyproline content in the extract treated animals supports the claims made by traditional healers of the benefits obtained from the medicinal use of K. pinnata.     

Effects of food restriction on stretch induced muscle hypertrophy in chickens of various ages

1. The patagialis muscle of three groups of different aged chickens was subjected to passive stretch by placing an inflexible sleeve over the left wing, and the right wing served as the control. 2. Food was removed from the animals 2 days prior to applying passive stretch. After 6 days of passive stretch on young 7-week-old animals, the stretched muscle was 200% larger than the control. 3. During the restriction, control muscle lost 69% of its weight and the stretched muscle maintained its original weight. 4. Changes in muscle DNA and hydroxyproline content were similar to changes in muscle weight but hydroxyproline content lagged changes in muscle weight. 5. Restricted 10-month-old chickens responded to passive stretch with an absolute increase in muscle mass which was accompanied by increases in protein, DNA and hydroxyproline content. 6. Muscle from the 28-month-old chickens did not respond to either 11 days of restriction or passive stretch. 7. The results of the present study indicate that as the chicken grows older, the ability of the muscle to respond to stimuli, stretch and/or starvation, is reduced.     

Antifibrogenic effect in vivo of low doses of insulin-like growth factor-I in cirrhotic rats.

Insulin-like growth factor-I (IGF-I) is produced mainly in the liver and it induces beneficial effects on the nutritional status, the liver function and oxidative hepatic damage in cirrhotic rats. The aim of this work was to analyze the effect of IGF-I on mechanisms of fibrogenesis in cirrhotic rats. Liver cirrhosis was induced by CCl(4) inhalation and phenobarbital in Wistar rats. Ten days after stopping CCl(4) administration (day 0), rats received either IGF-I (2 microg/100 g bw/day) (CI+IGF) or saline (CI) subcutaneously during 14 days. Animals were sacrificed on day 15. As control groups were used: healthy rats (CO) and healthy rats treated with IGF-I (CO+IGF). Liver histopathology, hydroxyproline content, prolyl hydroxylase activity, collagen I and III mRNA expression and the evolution of transformed Ito cells into myofibroblasts were assessed. Among the two control groups (CO+IGF), no differences were found in hydroxyproline content and these levels were lower than those found in the two cirrhotic groups. Compared with untreated cirrhotic rats, the CI+IGF-I animals showed a significant reduction in hydroxyproline content, prolyl hydroxylase activity and collagen alpha 1(I) and alpha1(III) mRNA expression. A higher number of transformed Ito cells (alpha-actin +) was observed in untreated cirrhotic animals as compared to CO and CI+IGF groups. In summary, treatment with IGF-I reduced all of the studied parameters of fibrogenesis. In conclusion, low doses of IGF-I induce in vivo an antifibrogenic effect in cirrhotic rats.     

Silicon deprivation decreases collagen formation in wounds and bone,and ornithine transaminase enzyme activity in liver

We have shown that silicon (Si) deprivation decreases the collagen concentration in bone of 9-wk-old rats. Finding that Si deprivation also affects collagen at different stages in bone development, collagen-forming enzymes, or collagen deposition in other tissues would have implications that Si is important for both wound healing and bone formation. Therefore, 42 rats in experiment 1 and 24 rats in experiment 2 were fed a basal diet containing 2 or 2.6 μg Si/g, respectively, based on ground corn and casein, and supplemented with either 0 or 10 μg Si/g as sodium metasilicate. At 3 wk, the femur was removed from 18 of the 42 rats in experiment 1 for hydroxyproline analysis. A polyvinyl sponge was implanted beneath the skin of the upper back of each of the 24 remaining rats. Sixteen hours before termination and 2 wk after the sponge had been implanted, each rat was given an oral dose of ¹⁴C-proline (1.8 μCi/100 g body wt). The total amount of hydroxyproline was significantly lower in the tibia and sponges taken from Si-deficient animals than Si-supplemented rats. The disintegrations per minute of ¹⁴C-proline were significantly higher in sponge extracts from Si-deficient rats than Si-supplemented rats. Additional evidence of aberrations in proline metabolism with Si deprivation was that liver ornithine aminotransferase was significantly decreased in Si-deprived animals in experiment 2. Findings of an increased accumulation of ¹⁴C-proline and decreased total hydroxyproline in implanted sponges and decreased activity of a key enzyme in proline synthesis (liver ornithine aminotransferase) in Si-deprived animals indicates an aberration in the formation of collagen from proline in sites other than bone that is corrected by Si. This suggests that Si is a nutrient of concern in wound healing as well as bone formation. The U.S. Department of Agriculture, Agricultural Research Service, Northern Plains Area is an equal opportunity/affirmative action employer, and all agency services are available without discrimination. Mention of a trademark or proprietary product does not constitute a guarantee or warranty of the product by the US Department of Agriculture and does not imply its approval to the exclusion of other products that may be suitable.     

Complement component C1q is sensitive to acute vitamin C defficiency in guinea pigs

In acutely scorbutic guinea pigs, where interstitial collagen synthesis is markedly impaired, there was no significant reduction in total complement component C1 activity measured by a functional assay, and no significant reduction in the ratio of protein-bound hydroxyproline to protein-bound proline or to total serum protein, in comparison with pair-fed controls. There was a moderate increase in non-protein-bound hydroxyproline in the serum of the deficient animals.These result suggest that component C1q is largely resistant to the effects of severe acute scurvy, adn that some hydroxyproline-containing proteins may respond differently others, during vitamin C deficiency.     

几种粉煤灰对磷素吸附与解吸特性的研究

通过吸附解吸和培养试验, 研究了几种粉煤灰对磷素吸附与解吸特性.结果表明,粉煤灰的全磷含量和有效磷含量分别为0.545～4.540 g·kg^-1和19.55～163.0 mg·kg^-1,显著高于土壤,粉煤灰对磷吸附量随着加入溶液磷浓度的增加而增加,但其吸附率随着加入溶液磷浓度的增加而减少;粉煤灰的吸磷率比土壤高,但其解吸率低.这主要是由于粉煤灰比土壤存在更多的磷吸附位点且结合能大,不易解吸.Langmuir方程、Freundlich方程和Temkin方程都能很好地拟合粉煤灰对磷吸附,其中Langmuir方程的MBC、Freundlich方程的a和Temkin方程的k2都可以表征粉煤灰对磷吸附能力, MBC、a和k2值越大,则吸磷能力越强.不同来源的粉煤灰的MBC、a和k2值不同,其大小顺序为：湘潭电厂(5 167.7,4 056.2,831.5)>岳阳纸厂(1 650.7,2 803.4,711.9)>华能电厂(303.0,1 677.6,368.7)>株洲电厂(76.2,464.2, 211.0) > 洞庭氮肥厂(34.7,413.48,213.8).粉煤灰对磷吸附固定作用随粉煤灰含水量的增加有增大的趋势.粉煤灰对磷吸附主要是专性吸附和化学沉淀反应,所以在施用粉煤灰改良土壤或利用粉煤灰制造复混肥时,须考虑粉煤灰对磷的固定作用及粉煤灰含水量的影响.     

Monocrotaline-induced pulmonary fibrosis in rats: amelioration by captopril and penicillamine

The purpose of this study was to determine whether Captopril (an angiotensin converting enzyme inhibitor) or D-penicillamine (an inhibitor of collagen crosslinking) can ameliorate pulmonary fibrosis induced by the plant alkaloid monocrotaline. Rats were randomly assigned to one of six treatment groups: (1) control; (2) Captopril, 60 mg/kg/day, p.o.; (3) D-penicillamine, 30 mg/kg/day, p.o.; (4) monocrotaline, 2.4 mg/kg/day, p.o.; (5) monocrotaline plus Captopril, as above; (6) monocrotaline plus penicillamine, as above; and were killed after 6 weeks of continuous drug administration. Monocrotaline-treated rats exhibited several anatomic correlates of pulmonary hypertension, including cardiomegaly, right heart enlargement, and muscularization of the pulmonary arteries and arterioles. These monocrotaline reactions were accompanied by decreased lung activities of angiotensin converting enzyme (ACE) and plasminogen activator (PLA), indicative of endothelial dysfunction; and by increased lung hydroxyproline concentration, indicative of interstitial fibrosis. The presence of interstitial fibrosis was confirmed by electron microscopy. When given concomitantly with monocrotaline, both Captopril and penicillamine partially prevented the cardiomegaly, right heart enlargement, and vascular muscularization. Both agents also diminished the decreased lung PLA activity and increased hydroxyproline concentration observed in monocrotaline-treated animals. Neither modifying agent influenced the monocrotaline-induced decrease in lung ACE activity. Compared with control rats, the rats receiving Captopril alone exhibited decreased heart weight and increased serum ACE activity, and animals receiving penicillamine alone did not differ significantly from control animals for any of the endpoints studied. These data demonstrate that Captopril and penicillamine ameliorate monocrotaline-induced pulmonary fibrosis in rats. Penicillamine, known to inhibit radiation-induced lung injury, thus is shown to be effective in a second model of pulmonary fibrosis. Perhaps more importantly, the hydroxyproline data demonstrate that the ACE inhibitor Captropril exhibits antifibrotic activity in monocrotaline-treated rat lung.     

Thyroxine-induced cardiomegaly in rats of different age

In the present study the effect of thyroxine treatment on the development of cardiomegaly was compared in young (10-day-old) and adult (12-week-old) rats. L-thyroxine was administered subcutaneously in a dose of 1 mg per kg b.w. for 5 days. In young thyroxine-treated rats the heart weight increased by 79% in comparison with the control rats. The number of blood capillaries and muscle fibres per mm2 remained unchanged. The concentration of hydroxyproline was even lower than in control animals. The number of 3H-thymidine-labelled muscle cell nuclei was significantly higher both in the left and right ventricles of thyroxine treated rats. The density of capillaries and muscle fibres was significantly lower in adult rats than in the group of young animals. In adult thyroxine-treated animals the heart weight was higher by 36%, the number of capillaries and muscle fibres as well as the concentration of hydroxyproline was unchanged. Thyroxine induced significant increase in the number of DNA synthesizing nuclei of muscle cells in the left ventricle while the change in the right ventricular myocardium was not statistically significant. The present data indicate that a hyperplastic response of cardiac muscle cells to thyroxine occurs in both ventricles of young rats and also in the left ventricle of adult animals.     

The protective effect of Ginkgo biloba extract on CCl4-induced hepatic damage

The aim of this study was to evaluate the protective effect of Ginkgo biloba extract on CCl4-induced hepatic damage in rats. Hepatic malondialdehyde, glutathione and hydroxyproline levels and histopathologic alterations in liver specimens were assessed. 200 mg/kg/day Ginkgo biloba extract were given orally to the animals for 10 days, then a single dose of 2 ml/kg b.w. carbon tetrachloride was, administered intraperitoneally. Ginkgo biloba extract treatment reduced hepatic malondialdehyde levels significantly (p < 0.05), but did not alter glutathione (p > 0.05) and hydroxyproline levels (p > 0.05). The light and electron microscopic findings showed that Ginkgo biloba extract limited the CCl4-induced hepatocyte necrosis and atrophy. These results suggest that this extract may protect the hepatocytes from carbon tetrachloride-induced liver injury.