Search results for "Procollagen"
showing 10 items of 58 documents
Age- and training-related changes in the collagen metabolism of rat skeletal muscle
1989
The effects of ageing and life-long endurance training on the collagen metabolism of skeletal muscle were evaluated in a longitudinal study. Wistar rats performed treadmill running 5 days a week for 2 years. The activities of collagen biosynthesis enzymes, prolyl-4-hydroxylase and galactosylhydroxylysyl glucosyltransferase, were highest in the muscles of the youngest animals, decreased up to the age of 2 months and from then on remained virtually unchanged. The enzyme activity in young animals was higher in the slow collagenous soleus muscle than in the rectus femoris muscle. The enzyme activity in the soleus muscle was higher for older trained rats than older untrained rats. The relative p…
Right ventricular collagen type III and IV gene expression increases during early phases of endurance training in hypobaric hypoxic condition
1997
The objective of this study was to examine the effects of prolonged exposure to hypobaric hypoxic condition, physical training and their combination on collagen type I, III and IV gene expression in the ventricles and atria of rat heart. Male rats were assigned to four groups: normobaric sedentary (NS) and trained (NT), and hypobaric sedentary (HS) and trained (HT). Exposure to and treadmill running training in hypobaric condition were carried out in a hypobaric chamber (770–740 mbar, 2250–2550 m). Experimental periods were 10, 21 and 56 days; the groups of 91 days served as recovery groups from experimental settings of 56 days. Exposure to hypobaric condition as such and in combination wit…
Report of a newly indentified patient with mutations in BMP1 and underlying pathogenetic aspects
2014
et al.
Loss of PHD3 allows tumours to overcome hypoxic growth inhibition and sustain proliferation through EGFR
2014
Solid tumours are exposed to microenvironmental factors such as hypoxia that normally inhibit cell growth. However, tumour cells are capable of counteracting these signals through mechanisms that are largely unknown. Here we show that the prolyl hydroxylase PHD3 restrains tumour growth in response to microenvironmental cues through the control of EGFR. PHD3 silencing in human gliomas or genetic deletion in a murine high-grade astrocytoma model markedly promotes tumour growth and the ability of tumours to continue growing under unfavourable conditions. The growth-suppressive function of PHD3 is independent of the established PHD3 targets HIF and NF-κB and its hydroxylase activity. Instead, l…
The deletion of six amino acids at the C-terminus of the alpha 1 (II) chain causes overmodification of type II and type XI collagen: further evidence…
1996
We have identified an 18 bp deletion in exon 49 of the type II procollagen gene (COL2A1) in a patient with Kniest dysplasia. The deletion is located at the very C-terminus of the helical domain and removes two of three Gly-Pro-Pro triplets at positions 1007-1012, which are thought to be involved in helix formation and stability. Morphological investigation of an iliac crest biopsy showed large inclusions in the endoplasmic reticulum of chondrocytes, reflecting impaired secretion of type II collagen. Electrophoretic analysis of collagens extracted from cartilage or synthesised by cultured chondrocytes showed that type II and also type XI procollagen molecules containing mutant alpha 1 (II) c…
mRNA levels for α-subunit of prolyl 4-hydroxylase and fibrillar collagens in immobilized rat skeletal muscle
1999
There is evidence that immobilization causes a decrease in total collagen synthesis in skeletal muscle within a few days. In this study, early immobilization effects on the expression of prolyl 4-hydroxylase (PH) and the main fibrillar collagens at mRNA and protein levels were investigated in rat skeletal muscle. The right hindlimb was immobilized in full plantar flexion for 1, 3, and 7 days. Steady-state mRNAs for α- and β-subunits of PH and type I and III procollagen, PH activity, and collagen content were measured in gastrocnemius and plantaris muscles. Type I and III procollagen mRNAs were also measured in soleus and tibialis anterior muscles. The mRNA level for the PH α-subunit decreas…
Increased prolyl 4-hydroxylase activity in the myocardium of endurance-trained mice.
1983
Endurance training over 3, 10 or 20 days increased the activity of prolyl 4-hydroxylase (PH) in the left ventricle of mice. No increase was observed in the weight of the left ventricle, in galactosylhydroxylysyl glucosyltransferase activity or in hydroxyproline concentration. The increase in PH suggests that the synthesis of collagen increases during physiological adaptation of the heart to endurance exercise without changes in the ventricle weight or its total collagen content.
Connective tissue of “fast” and “slow” skeletal muscle in rats…effects of endurance training
1980
The connective tissue of two skeletal muscles having different contractile properties was investigated in trained and untrained rats. The animals to be trained were put to run on a treadmill 5 days a week for 4 weeks. The "slow" m. soleus (MS) showed higher malate dehydrogenase activity but lower lactate dehydrogenase activity compared to the "fast" m. rectus femoris (MRF). When whole muscles were taken into account, the concentrations of both hydroxyproline and hexosamines were higher for MS compared to MRF. In the middle section of MS there were more hexosamines than in that of MRF, but no similar difference existed in hydroxyproline. The histochemical staining of collagen, however, sugge…
Increased activities of prolyl 4-hydroxylase and galactosylhydroxylysyl glucosyltransferase, enzymes of collagen biosynthesis, in skeletal muscle of …
1983
The activities of prolyl 4-hydroxylase (PH) and galactosylhydroxylysyl glucosyltransferase (GGT), and the concentration of 4-hydroxyproline were measured in red and white parts of quadriceps femoris muscle of mice after 3, 10, and 20 sessions of daily endurance training. The activities of PH and GGT increased in the red part of the muscle after training for 3 and 10 times and returned to the control level after 20 training sessions. In the white muscle the increase of PH activity was less than in the red muscle. No alteration in GGT activity was observed in the white muscle. The concentration of hydroxyproline was unchanged in the both types of skeletal muscle. The results suggest that coll…
Collagen metabolism of mouse skeletal muscle during the repair of exercise injuries.
1986
The activities of prolyl 4-hydroxylase and beta-glucuronidase, the concentration of hydroxyproline as well as reticulin and collagen type III, IV and V stainings were followed in skeletal muscle during a 20-day period after a 9-h treadmill running in untrained and trained male mice, aged 4-6 months. The prolonged 9-h running of untrained mice temporarily increased prolyl 4-hydroxylase activity 2, 5 and 10 days after exercise, more prominently in the red than in the white part of quadriceps femoris-muscle, and in analogical manner as beta-glucuronidase activity in tibialis anterior-muscle. Twenty days after exercise these enzymatic activities were back to the control level. The hydroxyprolin…