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Query: UMLS:C0038187 (starvation)
 24,951 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Male rabbits were injured by a single mechanical dilatation injury of aorta and then injected with prednisone 2 mg/kg or saline for 14 days or subjected to starvation. The biosynthesis of the sulfated glycosaminoglycans as evaluated by the uptake of 35S-sulfate and the content of the glycosaminoglycans were measured on the intima-media layer of the descending thoracic aorta. The results indicate that prednisone may inhibit the biosynthesis of heparan and/or dermatan sulfate while starvation increases the biosynthesis of all the sulfated glycosaminoglycans. No alterations were observed in the total amount of glycosaminoglycans in aorta following glucocorticoid injection or starvation. The metabolism of aortic glycosaminoglycans during repair is less sensitive to the action of prednisone than in undamaged aorta. This contrasts with the effect of prednisone on the metabolism of aortic collagen.
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PMID:Glucocorticoid and starvation effect on glycosaminoglycans in vascular connective tissue. Biochemical studies on repair processes in rabbit aorta. 13 64

Granulation tissue was produced in rats by subcutaneous implantation of viscose cellulose sponges. Treatment with cyclophosphamide in a dose of 10 mg/kg/day for 14 days caused an increase in acid soluble OH-proline and a decrease in alpha/beta ratio of acid soluble collagen of granulation tissue. Forty-two days of continuous cyclophosphamide treatment caused a decrease in dry weight, in free OH-proline, and in salt soluble OH-proline in granulation tissue. These findings are in accordance with previous observations of a decreased collagen synthesis and an inhibited collagen degradation in granulation tissue after cyclophosphamide treatment. In skin, the only change after cyclophosphamide was a decrease in total content of OH-proline and an increase in alpha/beta ratio of acid soluble collagen after 42 days of treatment. No effect of the subcutaneous sponge implantation was observed on the collagen variables in the skin. In comparison with unstarved controls, a reduction in dry weight and in free OH-proline in granulation tissue, as well as an increase in salt soluble OH-proline in the skin were observed 28 days after a 14-day treatment with cyclophosphamide. These observations indicate a sustained effect of cyclophosphamide on collagen 28 days after cessation of treatment. In addition the thermal stability of rat tail tendons was decreased 28 days after withdrawal of cyclophosphamide to the same extent as after starvation for 42 days and after 42 days of continuous cyclophosphamide treatment. It is concluded that the cyclophosphamide-induced collagen alterations, which may be of importance in the anti-inflammatory action of cyclophosphamide, are only in part reversible, 28 days after cessation of 14 days of cyclophosphamide treatment.
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PMID:Reversibility of the effects of cyclophosphamide on collagen: biochemical studies on skin and granulation tissue and determination of thermal stability of tail tendons of rats. 58 Jan 53

Male rabbits were injured by a single mechanical dilatation of the aorta and then injected with prednisone 2 mg/kg saline for 14 days or starved. Morphological studies and biochemical measurements of the collagen metabolism, the content of alpha-amino nitrogen, RNA, DNA, water and fat, and the aorta to serum ratio of 125I-albumin were performed on the intima-media layer of the descending thoracic aorta. Prednisone inhibited the intimal thickening. In the media the infiltration by mononuclear cells, the proliferation and regeneration of the smooth muscle cells and the calcification were reduced. Prednisone caused a decrease in 0.45 M NaCl soluble collagen as well as in the dialysable and non-dialysable 14C-hydroxyproline fractions. The total amount of collagen, elastin and alpha-amino nitrogen was unchanged, whereas the 14C-proline incorporation in the non-dialysable protein fraction was inhibited to a greater extent than the 14C-hydroxyproline synthesis. The findings indicate that prednisone inhibits the biosynthesis of collagen, which is inhibited to a greater extent than the general protein synthesis. Prednisone increased the dialysable to non-dialysable 14C-hydroxyproline ratio consistent with a relative increase in the catabolism of newly synthesized collagen. The aortic content of RNA and DNA was reduced consistent with the inhibition of protein synthesis and cell proliferation. Finally prednisone decreased the aortic content of water when related to the wet weight and increased the aortic content of fat. The aorta to serum ratio of 125I-albumin was not influenced by prednisone. It is concluded that administration of glucocorticoid for 14 days exerts an inhibitory action on the histological reaction to injury as well as on the biosynthesis of collagen of the repair processes in vascular connective tissue. A comparison with the effects of prednisone on undamaged rabbit aorta (Manthorpe et al. 1974) demonstrates that the metabolism of collagen of vascular connective tissue during repair is more sensitive to the antianabolic effects of prednisone than collagen in the non-injured aorta. Starvation caused an increase of the aortic percentage of water but otherwise had no influence on the repair processes in the vascular connective tissue.
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PMID:Glucocorticoid effect on repair processes in vascular connective tissue. Morphological examination and biochemical studies on collagen RNA and DNA in rabbit aorta. 124 73

Glucose starvation has been widely used to select differentiated subpopulations from the heterogenous human colon cancer cell line HT29. We observed that the important cell loss elicited by culturing these cells in glucose-free medium could be limited when type I collagen gel was used as substratum instead of conventional plastic support. We took advantage of this property to develop a new protocol, which combined glucose starvation and culture on collagen gels, for cloning HT29 cells. Using this procedure we have isolated four clones that were characterized on the basis of morphological (optical and transmission electron microscopy), electrophysiological (determination of transepithelial electrical parameters) and biochemical (detection of villin, sucrase-isomaltase and carcinoembryonic antigen) criteria. These four clones expressed different patterns of enterocytic differentiation regarding to these criteria. These results confirmed the heterogeneity of the HT29 cell line. One of these clones, HT29-A7, which displayed numerous intercellular cysts that disappeared at confluency, appears as a complementary model in the study of epithelial biogenesis.
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PMID:Combination of culture on collagen gels and glucose starvation for cloning human colon cancer cells. Obtention of clones exhibiting different patterns of enterocytic differentiation. 136 54

The effects of modified protein sparing therapy (PSP) and total parenteral nutrition (TPN) on total and wound metabolism were studied for 96 hours after laparotomy and a small gastric excision in 40 rabbits starved for seven days. A further eight starved and eight non-starved animals served as controls for the blood variables. Normal healing up to day 14 was studied in 20 non-starved animals. The difference in deaths and animals in poor condition, 42.1 per cent in PSP and 18.6 per cent in TPN, respectively, was clear but statistically non-significant. PSP led to a lower mean serum albumin concentration than TPN, 25.7 +/- 3.7 (SD) and 28.7 +/- 3.0 (p = 0.02), respectively. The animals receiving PSP excreted significantly more 3-methylhistidine. TPN maintained a positive nitrogen balance, but PSP produced a negative one. The collagen content of the skin scar was lower after PSP (3.1 +/- 0.7 mg) than after TPN (4.5 +/- 1.3 mg) (p less than 0.05), the latter coming close to the level for normal 4-day healing, 4.5 +/- 1.2 mg. Prolyl 4-hydroxylase (PPH) activity showed no difference. No inter-group differences in collagen were found in the stomach. Both regimens totally reversed the starvation-induced decrease in PPH activity in the stomach, but only partially in skin. Thus TPN produced better total and skin wound metabolism after laparotomy and starvation than did PSP. No differences in visceral wound healing were observed.
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PMID:Effect of intravenous feeding on wound healing in starvation: an experimental study on the rabbit. 193 25

Existing hypotheses suggest that the effect of food deprivation on bone occurs via alterations in the synthesis of the organic matrix. Thus, this work was carried out to characterize the modifications of the physico-chemical properties of the proteoglycans (PG) of rat hyaline cartilage and femur. Male Wistar rats were assigned at random to a control group which was fed a standard pellet diet or to an experimental group which was given water "ad libitum" and starved over the experimental period. On day 4 or 8 the animals were administered a dose of 35S, weighed and killed. PG and glycosaminoglycans (GAG) were isolated from femurs and xyphoid cartilages. Uptake of 35S, GAG distribution patterns, PG molecular weight, molecular size of the side chains and the PG density gradient were determined. The aforementioned parameters decreased significantly after 4 and 8 days of total starvation. The GAG distribution pattern only exhibited a reduction of the Chondroitin-4-Sulphate fraction. These changes could alter the binding properties of PG to other macromolecules such as collagen which plays an important role in the ossification process.
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PMID:Effect of total food deprivation on the proteoglycans of rat hyaline cartilage and bone. 251 62

Fibronectin is a normal glycoprotein component of plasma, interstitial fluid, and extracellular matrix which has binding sites for collagen, gelatin, actin, glycosaminoglycans, fibrin, Staphylococcus aureus, and some cells. Since it is a dimer, it can crosslink these substances to each other or to extracellular components of basement membrane, thereby affecting many physiological processes. The level of circulating fibronectin is markedly reduced following even moderate blunt or operative trauma, thermal injury, starvation, advanced cancers, hemorrhage, etc. Replacement therapy has been tried with some success in patients who become septic following multiple injuries. The reduction in plasma fibronectin has been attributed to several causes including consumption by binding to cell debris at the site of injury, binding to circulating cell debris and its subsequent removal by elements of the phagocytic system, and degradation by proteolytic cleavage. However, the amount of fibronectin removed from circulation raises some question about this. In this paper, we used indomethacin, ibuprofen, imidazole, and essential fatty acid deprivation to inhibit the synthesis of prostaglandins in young adult rats. Thirty minutes after ip administration of one of the inhibitors, the rats were subjected to a midline laparotomy and mild intestinal manipulation. Blood samples were taken at intervals following closure of the incision and analyzed for fibronectin. In all cases, the normal decline in plasma fibronectin seen in untreated rats was abrogated by inhibiting prostaglandin synthesis. Since imidazole specifically inhibits thromboxane A synthesis, this strongly suggests that thromboxanes directly or indirectly control the trauma-induced reduction in circulating fibronectin. This was confirmed by ip injection of thromboxane into the rats which resulted in a decline in plasma fibronectin levels.
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PMID:Role of prostaglandins in controlling plasma fibronectin levels. 304 45

The effects of dietary protein, fasting, and refeeding on urinary hydroxyproline of nine captive female white-tailed deer (Odocoileus virginianus) were examined from 23 February to 3 May 1984 in northern Minnesota. In the fasted group, mean hydroxyproline:creatinine (OHP:C) was greater (P less than 0.05) at week 4 compared to baseline at week 0. Between fasted deer and deer fed high protein-high energy (HPHE) and low protein-high energy (LPHE) diets, no difference in OHP:C ratios was detected during the initial 4 wk of the study. Urinary OHP:C ratios were significantly (P less than 0.05) greater in the fasted group during refeeding, concomitant with greater feed consumption and weight gain. There was also a significant (P less than 0.02) time effect in the fasted-refed group; OHP:C ratios increased during these two phases of the study. There was no difference between the HPHE and LPHE fed deer in renal OHP excretion. However, mean OHP:C ratios in yearlings (16.8 +/- 2.2) were greater (P less than 0.001) than in the adults (7.5 +/- 1.2) of those groups, indicating a higher collagen turnover rate. Urinary OHP:C shows potential as an indicator of growth and starvation, and the data presented may serve as reference values.
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PMID:Response of urinary hydroxyproline to dietary protein and fasting in white-tailed deer. 335

The effect of starvation on lung mechanics, morphometry, and levels of connective tissue components was determined in young adult golden Syrian hamsters. A base-line control, fed control, and starved group were studied. Fed group animals increased body weight by 13%, but dry lung weight did not increase above that of the base-line controls. The total lung capacity when transpulmonary pressure was at 25 cmH2O (TLC25) also increased by 20% above base-line controls. The mean TLC25 of the starved group was greater than that of the base-line control group but less than that of the fed control group (P less than 0.05). Volume-corrected air-filled volume pressure (VP) curves of the three groups were similar. Volume-corrected saline-filled VP curves were identical in the three groups. Total lung collagen, elastin, glycosaminoglycan, and protein were similar in the three groups. Air space size was significantly increased and mean internal surface area was significantly decreased in the starved group compared with the base-line and fed controls. No evidence of alveolar wall destruction was evident by light or electron microscopy. We conclude that severe starvation of young adult hamsters produces air space enlargement without changes in lung elastic recoil. The mechanism of alveolar wall remodeling is not yet understood in this model of emphysema.
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PMID:Lung mechanics and connective tissue levels in starvation-induced emphysema in hamsters. 374 Mar 10

Prednisolone (2 mg/kg) was injected daily for 14 days. Collagen and protein biosynthesis were measured in isolated molar and incisor pulps by the incorporation of [14C]-proline into protein and collagen in vitro. Collagen solubility, free proline content, prolyl hydroxylase activity, collagenolytic activity and DNA and RNA contents were also assayed. Rabbits injected with saline or starved served as controls. Collagen synthesis was inhibited selectively in both prednisolone and starvation groups. No other aspect of collagen and protein metabolism was affected by either prednisolone treatment or starvation. Thus glucocorticoid administration reduces collagen formation in the pulp, resembling the anti-anabolic effect of starvation. Glucocorticoid treatment at high daily dosages, therefore, may disturb normal development and metabolism of teeth.
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PMID:Selective inhibition of collagen biosynthesis in the dental pulps of glucocorticoid-treated rabbits. 619 Apr 70


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