Kakvoća mesa istarskog goveda Cukon, mr. Nenad; Cvrtila Fleck, Željka; Kozačinski, Lidija ...
MESO: Prvi hrvatski časopis o mesu,
04/2012, Letnik:
XIV, Številka:
2
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Cilj ovog rada je bio utvrditi kakvoću goveđeg mesa istarskog goveda, koristeći se pri tome rezultatima kemijskih analiza za kakvoću njihova mesa. Za potrebe kemijskih pretraga uzorkovano je ...5 uzoraka mesa muške junadi istarskog goveda na kraju tova, u dobi od prosječno 23 mjeseca. Uzorci su uzorkovani iz m. longissimus dorsi (MLD) između 7. i 9. rebra, i laboratorijske pretrage obuhvatile su osnovnu kemijsku pretragu, količinu kolagena i hidroksiprolina, te masnokiselinski sastav lipida intramuskularne masti u MLDa. Dobiveni rezultati ukazali su da meso istarskog goveda po svom osnovnom kemijskom sastavu nije odstupalo od sastava mesa simentalskog goveda, osim u činjenici da je količina intramuskularne masti iznosila prosječno 0,94 ± 0,65 % , što je gotovo trostruko manje nego kod simentalskog goveda. Prožetost mesa istarskog goveda vezivnim tkivom je relativno prihvatljivo, pri čemu je njegova količina u pozitivnoj korelaciji s nježnošću mesa. Rezultati masnokiselinskog sastava lipida intramuskularne masti mesa istarskog goveda pokazali su zamjetnu količinu zasićenih masnih kiselina (oko 60%), što tom mesu ne daje baš cjelovitu nutricionističku prednost. No, s gledišta održivosti, a time i kakvoće, takvo meso je zbog toga, te zbog manje količine polinezasićenih masnih kiselina (2,41 ± 0,60%), manje podložno autooksidativnim promjenama pri dužem uskladištenju ili pak prilikom prerade mesa u asortiman mesnih proizvoda u tipu kobasice. Sveukupno, dobiveni rezultati našeg istraživanja ukazuju da meso istarskog goveda ima povoljnu kakvoću za kulinarsku pripremu, slijedom čega uzgoj i podizanje samoodrživosti pasmine imaju budućnost. Zbog činjenice da se populacija istarskog goveda od gotovo 40.000 primjeraka prije 50 godina snizila na samo oko 530 uzgojno valjanih rasplodnih jedinki, većina stručnjaka, kojima se pridružuju rezultati naših istraživanja, ukazuju na značaj, vrijednost i potrebu da se ta pasmina goveda očuva.
Activated hepatic stellate cells (HSC) are a major source offibrous proteins in cirrhotic liver. Inducing or accelerating their apoptosis is a potential way of liver fibrosis treatment. Extracellular ...matrix (ECM) surrounding cells in tissue affects their differentiation, migration, proliferation and function. Type I collagen is the main ECM component in fibrotic liver. We have examined how this protein modifies apoptosis of normal rat HSC induced by gliotoxin, cycloheximide and cytochalasin D in vitro and spontaneous apoptosis of HSC isolated from CCl4-damaged liver. We have found that type I collagen gel enhances HSC apoptosis regardless of the agent triggering this process.
L. Bittnerová, A. Jiroutová, E. Rudolf, M. Rezácová, J. Kanta
Mariia Lunova, Sona Frankova, Halima Gottfriedova, Renata Senkerikova, Magdalena Neroldova, Jozef Kovac, Eva Kieslichova, Vera Lanska, Eva Sticova, Julius Spicak, Milan Jirsa, Jan Sperl.
Obsahuje ...bibliografii
Liver stiffness (LS) is a novel non-invasive parameter widely used in clinical hepatology. LS correlates with liver fibrosis stage in non-cirrhotic patients. In cirrhotic patients it also shows good correlation with Hepatic Venous Pressure Gradient (HVPG). Our aim was to assess the contribution of liver fibrosis and portal hypertension to LS in patients with advanced liver cirrhosis. Eighty-one liver transplant candidates with liver cirrhosis of various aetiologies underwent direct HVPG and LS measurement by 2D shear-wave elastography (Aixplorer Multiwave, Supersonic Imagine, France). Liver collagen content was assessed in the explanted liver as collagen proportionate area (CPA) and hydroxyproline content (HP). The studied cohort included predominantly patients with Child-Pugh class B and C (63/81, 77.8 %), minority of patients were Child-Pugh A (18/81, 22.2 %). LS showed the best correlation with HVPG (r=0.719, p<0.001), correlation of LS with CPA (r=0.441, p<0.001) and HP/Amino Acids (r=0.414, p< 0.001) was weaker. Both variables expressing liver collagen content showed good correlation with each other (r=0.574, p<0.001). Multiple linear regression identified the strongest association between LS and HVPG (p<0.0001) and weaker association of LS with CPA (p = 0.01883). Stepwise modelling showed minimal increase in r2 after addition of CPA to HVPG (0.5073 vs. 0.5513). The derived formula expressing LS value formation is: LS=2.48 + (1.29 x HVPG) + (0.26 x CPA). We conclude that LS is determined predominantly by HVPG in patients with advanced liver cirrhosis whereas contribution of liver collagen content is relatively low.
Výskyt degenerativních onemocnění kloubů stoupá nejenom s věkem sledovaných osob, ale taktéž je pozorována vzestupná tendence prevalence a incidence v celé populaci. Bolesti nosných kloubů i kloubů ...ruky vznikají na multifaktoriálním podkladu s genetickou zátěží. Bolesti se mohou vyskytnout při zátěži, ale i v klidu. Terapie je symptomatická se snahou omezit degenerativní procesy a především odstranit bolestivost. V ambulanci praktického lékaře je vhodné využít komplexního postupu. Lze běžně užít preparátu NSAID, ale taktéž zvážit i některé potravní doplňky.
Occurrence of osteoarthritis increases not only with age of monitored individuals, but also an upward trend is observed both in the prevalence and incidence in the whole population. Pain in the hip and knee joints arise on a multi-factorial basis with genetic load. The pain can occur both during physical activity and at rest. The therapy is symptomatic with an effort to reduce degenerative processes and mainly to eliminate soreness. It is suitable to use a complex procedure at the GP's outpatient department. It is also possible to use NSAIDs, or recommend dietary supplements as well.
Jan Hlúbik, Pavol Hlúbik
Literatura 7
Izolirana je nova bakterija koja proizvodi kolagenazu, identificirana kao Bacillus cereus MBL13. Iz supernatanta kulture B. cereus MBL13, uzgojene na koštanom kolagenu kao izvoru ugljika i dušika, ...izdvojena je ekstracelularna proteaza sa sposobnošću razgradnje životinjskih kostiju. Procijenjena je molekularna masa pročišćene kolagenolitičke proteaze od (38,0±1,5) kDa. Analiziran je aminokiselinski sastav i utvrđeno da enzim sadržava veliku količinu asparagina, lizina i serina. Optimalna temperatura za aktivnost kolagenaze bila je 40 °C, a optimalna pH-vrijednost 8,0. Prema utjecaju iona metala, inhibitora i proteinskih supstrata na aktivnost enzima zaključeno je da enzim pripada u grupu metaloproteaza. Kolagen tipa I (tipični sastojak životinjskih kostiju) upotrijebljen je kao supstrat pri određivanju parametara Michaelis-Mentenove kinetike. Km vrijednost bila je (1,31±0,05) g/L, a vmax (12,54±2,5) μmol/min. Zaključeno je da se kolagenolitička proteaza izdvojena iz B. cereus MBL13 može upotrijebiti za razgradnju životinjskih kostiju.
ZusammenfassungDas Ziel dieser Arbeit war, die Qualität des Fleisches vom Rind aus Istrien zu bestimmen, wobei die Resultate der chemischen Analysenhinsichtlich Fleischqualität benutzt wurden. Für ...den Bedarf der chemischen Analysen wurden Musterproben von 5 männlichen Jungstieren des Rindes aus Istrien genommen. Sie waren am Mastende, durchschnittlich 23 Monate alt. Die Musterproben wurden aus m. longissimus dorsi (MLD) zwischen der 7. und 9. Rippe genommen. Die Laboruntersuchungen umfassten die chemische Grunduntersuchung, Kollagenmenge und Hydroxyproline, sowie die fettsäuerliche Zusammensetzung der Lipide des intramuskulären Fettes in MLD. Die bekommenen Resultate zeigten, dass sich das Fleisch vom Rind aus Istrien seiner chemischen Grundzusammensetzung nach von der Zusammensetzung des Fleisches von Simmentalern nicht unterschieden hat, außer dass die Menge des intramuskulären Fettes durchschnittlich 0,94 ± 0,65 % betrug, was fast dreimal so wenig als bei den Simmentalern ist. Das Durchdringen des Fleisches vom Rind aus Istrien mit Bindegewebe ist relativ annehmbar, wobei seine Menge in positiver Korrelation mit Fleischzartheit steht. Die Resultate der fettsäuerlichen Zusammensetzung der Lipide des intramuskulären Fettes vom Rind aus Istrien zeigten eine bemerkbare Menge der gesättigten Fettsäuren (etwa 60 %), was diesem Fleisch nicht gerade einen gesamten nutrizionistischen Vorteil verleiht. Aber aus der Sicht der Erhaltbarkeit und der Qualität, ist dieses Fleisch deshalb und auch wegen einer kleineren Menge der poliungesättigten Fettsäuren (2,41 ± 0,60 %) weniger den autooxidativen Veränderungen bei längerer Lagerung ausgesetzt, was auch für die Fleischverarbetung in das Assortiment der Fleischerzeugnisse bzw. Würste gilt. Die gesamten Resultate unserer Untersuchung zeigen, dass das Fleisch vom Rind aus Istrien eine günstige Qualität für die kulinarische Zubereitung hat. Die Zucht und die Selbsterhaltung der Rasse haben somit eine Zukunft. Da die Population des Rindes aus Istrien von fast 40.000 Exemplaren vor 50 Jahren auf nur 530 für die Zucht und Brut geeigneten Einzelwesen sank, zeigen unsere Resultate und die Untersuchungen anderer Fachleute auf die Bedeutung, den Wert und den Bedarf, dass diese Rindrasse erhalten wird.
SomarioLo scopo di questo articolo era determinare la qualità di carne dei bovini istriani, usando i risultati delle analisi chimiche che riguardanola qualità della loro carne. Per poter fare le ricerche chimiche sono stati presi 5 campioni dai bovini istriani maschi alla fi ne diallevamento, nell’età di approssimativamente 23 mesi ciascuno. I campioni sono stati presi dal m. Longissimus dorsi (MLD) tra la 7ae la 9a coscia, e le ricerche in laboratorio hanno incluso la ricerca chimica fondamentale, quantità di collageno e di idrossiprolina, ela composizione di acidi grassi di lipidi del grasso intramuscolare nel MLD. I risultati ottenuti hanno mostrato che la carne del bovinoistriano non deviava dalla composizione di carne dei bovini di razza simentale, salvo il fatto che la quantità del grasso intramuscolareera in media 0,94 ± 0,65 %, che fa quasi tre volte di meno che dal bovino di razza simentale. Il contenuto del tessuto connettivonella carne del bovino istriano è relativamente accettabile, e la sua quantità è in correlazione positiva con la tenerezza della carne.I risultati della composizione di acidi grassi nella carne del bovino istriano hanno mostrato una quantità notevole degli acidi grassisaturi (all’incirca 60 %), e questo non è un vantaggio specialmente nutritivo. Per questa ragione, dal punto di vista di sostenibilità equello di qualità, ma anche per la quantità evidente di grassi acidi saturi (2,41 ± 0,60%), la carne è meno suscettibile alle alterazioniautoossidative durante un immagazzinamento prolungato oppure nel caso di lavorazione di carne nell’assortimento di prodotti dicarne tipo salsiccia. Tutto sommato, i risultati che abbiamo ottenuto da questa ricerca rivelano che la carne del bovino istriano è diuna qualità accettabile per preparazione culinaria, e perciò possiamo concludere che l’allevamento e la crescita di sostenibilità diquesta razza hanno un futuro garantito. Grazie al fatto che la popolazione del bovino istriano da quasi 40 000 entità 50 anni fa èstata ridotta ai soli 530 entità addatte all’allevamento riproduttivo, la maggior parte di professionisti – motivati anche dalle nostrericerche – puntano l’importanza, il valore e la necessità di salvare questa razza di bovini.
SažetakCilj ovog rada je bio utvrditi kakvoću goveđeg mesa istarskog goveda, koristeći se pri tome rezultatima kemijskih analiza za kakvoću njihova mesa. Za potrebe kemijskih pretraga uzorkovano je 5 uzoraka mesa muške junadi istarskog goveda na kraju tova, u dobi od prosječno 23 mjeseca. Uzorci su uzorkovani iz m. longissimus dorsi (MLD) između 7. i 9. rebra, i laboratorijske pretrage obuhvatile su osnovnu kemijsku pretragu, količinu kolagena i hidroksiprolina, te masnokiselinski sastav lipida intramuskularne masti u MLDa. Dobiveni rezultati ukazali su da meso istarskog goveda po svom osnovnom kemijskom sastavu nije odstupalo od sastava mesa simentalskog goveda, osim u činjenici da je količina intramuskularne masti iznosila prosječno 0,94 ± 0,65 % , što je gotovo trostruko manje nego kod simentalskog goveda. Prožetost mesa istarskog goveda vezivnim tkivom je relativno prihvatljivo, pri čemu je njegova količina u pozitivnoj korelaciji s nježnošću mesa. Rezultati masnokiselinskog sastava lipida intramuskularne masti mesa istarskog goveda pokazali su zamjetnu količinu zasićenih masnih kiselina (oko 60%), što tom mesu ne daje baš cjelovitu nutricionističku prednost. No, s gledišta održivosti, a time i kakvoće, takvo meso je zbog toga, te zbog manje količine polinezasićenih masnih kiselina (2,41 ± 0,60%), manje podložno autooksidativnim promjenama pri dužem uskladištenju ili pak prilikom prerade mesa u asortiman mesnih proizvoda u tipu kobasice. Sveukupno, dobiveni rezultati našeg istraživanja ukazuju da meso istarskog goveda ima povoljnu kakvoću za kulinarsku pripremu, slijedom čega uzgoj i podizanje samoodrživosti pasmine imaju budućnost. Zbog činjenice da se populacija istarskog goveda od gotovo 40.000 primjeraka prije 50 godina snizila na samo oko 530 uzgojno valjanih rasplodnih jedinki, većina stručnjaka, kojima se pridružuju rezultati naših istraživanja, ukazuju na značaj, vrijednost i potrebu da se ta pasmina goveda očuva.
SummaryThe goal of this work was to determine the beef meat quality of Istrian cattle using the chemical analyses’ results for the quality ofits meat. Five meat samples of Istrian cattle bull calves were sampled for the needs of chemical analyses at the end of fattening, at23 months of age on average. The samples were sampled from m. longissimus dorsi (MLD) between the 7th and the 9th rib andlaboratory researches included the basic chemical research, collagen and hidroxyproline quantity and fatty acid content of lipids inintramuscular fat in MLD. The obtained results have shown that the meat of Istrian cattle by its basic chemical composition did notdiff er from the content of meat of Simmental cattle, except in the fact that quantity of intramuscular fat was in average 0.94 ± 0.65 %,which is almost three times lower than in Simmental cattle. The content of connective tissue in the meat of Istrian cattle is relativelyacceptable, where its quantity is in a positive correlation with meat tenderness. The results of fatty acid content of lipids in intramuscularfat in the meat of Istrian cattle have shown a signifi cant quantity of saturated fatty acids (about 60%), which doesn’t givethis meat a complete nutritional advantage. But, from the point of view of sustainability and quality, because of that and a smallerquantity of polyunsaturated fatty acids (2.41 ± 0.60%), such meat is less prone to auto oxidative changes in longer storage period orduring processing of meat to the assortment of meat products in sausage type. Overall, the obtained results of our research indicatethat the meat of Istrian cattle has a favorable quality for culinary preparation. Therefore, breeding and increasing self-sustainabilityof this breed has the future. Due to the fact that the population of Istrian cattle of almost 40.000 individuals 50 years ago reduced toonly about 530 breeders suitable for breeding, most experts emphasize the signifi cance, value and need for that cattle breed to be preserved. Our researches’ results agree with it.
L. Koláčná, J. Bakešová, F. Varga, E. Košťáková, L. Plánka, A. Nečas, D. Lukáš, E. Amler, V. Pelouch.
Obsahuje bibliografii
ECM is composed of different collagenous and non-collagenous proteins. ...Collagen nanofibers play a dominant role in maintaining the biological and structural integrity of various tissues and organs, including bone, skin, tendon, blood vessels, and cartilage. Artificial collagen nanofibers are increasingly significant in numerous tissue engineering applications and seem to be ideal scaffolds for cell growth and proliferation. The modern tissue engineering task is to develop three-dimensional scaffolds of appropriate biological and biomechanical properties, at the same time mimicking the natural extracellular matrix and promoting tissue regeneration. Furthermore, it should be biodegradable, bioresorbable and non-inflammatory, should provide sufficient nutrient supply and have appropriate viscoelasticity and strength. Attributed to collagen features mentioned above, collagen fibers represent an obvious appropriate material for tissue engineering scaffolds. The aim of this minireview is, besides encapsulation of the basic biochemical and biophysical properties of collagen, to summarize the most promising modern methods and technologies for production of collagen nanofibers and scaffolds for artificial tissue development.
M. Adamcová ... et al..
Obsahuje bibliografii a bibliografické odkazy
The matrix metalloproteinases (MMPs) play a key role during cardiac remodeling. The aim of the study was to investigate the ...changes in collagenous proteins and MMPs in the model of non-ischemic, anthracycline-induced chronic cardiomyopathy in rabbits using both biochemical and histological approaches. The study was carried out in three groups of Chinchilla male rabbits: 1) daunorubicin (3 mg/kg, once weekly for 10 weeks), 2) control (saline in the same schedule), 3) daunorubicin with the cardioprotectant dexrazoxane (60 mg/kg, before each daunorubicin). Morphological changes in the myocardium of daunorubicin-treated animals were characterized by focal myocardial interstitial fibrosis of different intensity. The subsequent proliferation of the fibrotic tissue was marked by an increased content of both collagen types I and III, which resulted in their typical coexpression in the majority of bundles of fibers forming either smaller or larger scars. Biochemical analysis showed a significantly increased concentration of hydroxyproline, mainly in the pepsin-insoluble fraction of collagenous proteins, in the daunorubicin-treated group (1.42±0.12 mg/g) as compared with the control (1.03±0.04 mg/g) and dexrazoxane (1.07±0.07 mg/g) groups. Dexrazoxane co-administration remarkably reduced the cardiotoxic effects of daunorubicin to the extent comparable with the controls in all evaluated parameters. Using zymography, it was possible to detect only a gelatinolytic band corresponding to MMP-2 (MMP-9 activity was not detectable). However, no significant changes in MMP-2 activity were determined between individual groups. Immunohistochemical analysis revealed increased MMP-2 expression in both cardiomyocytes and fibroblasts. Thus, this study has revealed specific alterations in the collagen network in chronic anthracycline cardiotoxicity in relationship to the expression and activity of major MMPs.
Cíl studie: Sledovat vliv opakovaných krevních odběrů a diety obohacené o železo na kostní metabolismus u samců potkanů kmene Wistar. Typ studie: Základní výzkum. Název a sídlo pracoviště: Vivárium a ...radioizotopové laboratoře, LF UK Hradec Králové, Ústav klinické biochemie a diagnostiky, Fakultní nemocnice Hradec Králové. Materiál a metody: Potkani byli po dobu 8 týdnů krmeni standardní laboratorní dietou (SLD, 27 mg Fe/kg diety) nebo dietou obohacenou o železo (FE, 400 mg Fe/kg diety). Týdně byl proveden odběr (w) 0,5 ml krve/100 g tělesné hmotnosti, celkem 8krát. Skupiny: 1. kontrolní skupina SLD; 2. kontrolní skupina FE; 3. SLD-w; 4. FE-w. V krvi byl stanoven krevní obraz, respiratorní vzplanutí (RB), v séru koncentrace prohepcidinu a železa, v játrech koncentrace železa. Z kostních ukazatelů jsme stanovili: osteokalcin (OC), N-terminální propeptid prokolagenu typu I (PINP), C-terminální telopeptid kolagenu typu I (CTx) a tartát-rezistentní kyselou fosfatázu (TRACP). Byla změřena kostní minerální hustota (BMD). Výsledky: U skupin s krevními odběry bylo vyšší spontánní RB a železo v séru, naopak došlo k poklesu sérového prohepcidinu, hemoglobinu i železa v játrech ve srovnání s SLD a FE, u FE-w bylo také vyšší stimulované RB. Hodnoty PINP (p < 0,05), CTx (p < 0,05) a TRAP (p < 0,05) vzrostly u SLD-w ve 3. týdnu a u FE-w v 1. týdnu, hodnoty OC (p < 0,05) vzrostly pouze u FE-w v 1. týdnu, poté všechny hodnoty poklesly na hodnoty SLD a FE. BMD vzrostla po odběrech v bederní a ocasní oblasti (p < 0,01). Závěr: Opakované krevní odběry a dieta obohacená o železo vedly k vyšší reaktivitě buněk makrofágového systému, k vyšší aktivitě osteoklastů, ke stimulaci osteoblastů s následným pozitivním vlivem na kvalitu kostní tkáně. Klíčová slova: odběr krve, železo, osteokalcin, N-terminální propeptid prokolagenu typu I, C-terminální telopeptid kolagenu typu I.
Objective: We studied the infl uence of repeated blood withdrawals and iron enriched diet on biochemical markers of bone metabolism in male Wistar rats. Design: Basic research. Settings: Radioisotope Laboratories and Vivarium, Charles University, Medical Faculty, Hradec Kralove, Institute of Clinical Biochemistry and Diagnostics, University Hospital, Hradec Kralove. Material and Methods: Rats were fed for 8 weeks with standard laboratory diet (SLD, 27mg Fe/kg diet) or iron enriched diet (FE, 400 mg Fe/kg diet) and had blood withdrawals (w) 0.5 ml/100 g body weight, 8 times. Animals were divided into 4 groups: 1. Control group SLD; 2. Control group FE; 3. SLD-w; 4. FE-w. The following items were assessed in blood; haemoglobin concentration and respiratory burst (RB), iron stores in liver tissue. In serum were evaluated prohepcidin, iron and bone metabolism markers: osteocalcin (OC), N-terminal propeptid of procollagen I (PINP), C-terminal telopeptide of collagen I (CTx) and tartrate resistant acid phosphatase (TRACP). Bone mineral density (BMD) was measured. Results: Spontaneous RB and iron in serum increased in animals with repeated blood withdrawals, but serum prohepcidin, haemoglobin concentration and iron in liver decreased vs. SLD and FE, but in FE-w animals increased stimulated RB, too. Values of PINP (p < 0.05), CTx (p < 0.05) and TRAP (p < 0.05) increased by SLD-w in 1st week and by FE-w in 3rd week, values of OC (p < 0.05) increased only by FE-w, but then all these values decreased to values of SLD and FE. BMD increased by blood withdrawals in femur (p < 0.01) and lumbar part (p < 0.01). Conclusion: Repeated blood withdrawals and iron enriched diet contributed to stimulation reactivity of scavenger cells, elevation activity of osteoclast, stimulation of osteoblast with subsequent positive effect on quality of bone tissue. Key words: blood withdrawal, iron, osteocalcin, N-terminal propeptide of procollagen I, C-terminal telopeptide of collagen I.
Švejkovská K., Doubková K., Živná H., Živný P., Palička V.
Lit.: 19
J. Novotná, J. Bíbová, V. Hampl, Z. Deyl, J. Herget.
Obsahuje bibliografii
a1_Chronic hypoxia causes pulmonary hypertension, the mechanism of which includes altered collagen metabolism in the ...pulmonary vascular wall. This chronic hypoxic pulmonary hypertension is gradually reversible upon reoxygenation. The return to air after the adjustment to chronic hypoxia resembles in some aspects a hyperoxic stimulus and we hypothesize that the changes of extracellular matrix proteins in peripheral pulmonary arteries may be similar. Therefore, we studied the exposure to moderate chronic hyperoxia (FiO2 = 0.35, 3 weeks) in rats and compared its effects on the rat pulmonary vasculature to the effects of recovery (3 weeks) from chronic hypoxia (FiO2 = 0.1, 3 weeks). Chronically hypoxic rats had pulmonary hypertension (Pap = 26±3 mm Hg, controls 16±1 mm Hg) and right ventricular hypertrophy. Pulmonary arterial blood pressure and right ventricle weight normalized after 3 weeks of recovery in air (Pap = 19±1 mm Hg). The rats exposed to moderate chronic hyperoxia also did not have pulmonary hypertension (Pap = 18±1 mm Hg, controls 17±1 mm Hg). Collagenous proteins isolated from the peripheral pulmonary arteries (100-300 mm) were studied using polyacrylamide gel electrophoresis. A dominant low molecular weight peptide (approx. 76 kD) was found in hypoxic rats. The proportion of this peptide decreases significantly in the course of recovery in air. In addition, another larger peptide doublet was found in rats recovering from chronic hypoxia. It was localized in polyacrylamide gels close to the zone of a2 chain of collagen type I. It was bound to anticollagen type I antibodies. An identically localized peptide was found in rats exposed to moderate chronic hyperoxia. The apparent molecular weight of this collagen fraction suggests that it is a product of collagen type I cleavage by a rodent-type interstitial collagenase (MMP-13).
a2_We conclude that chronic moderate hyperoxia and recovery from chronic hypoxia have a similar effect on collagenous proteins of the peripheral pulmonary arterial wall.
