Metabolism collagen

Sodek J and Mandell SM (1982) Collagen metabolism in rat incisor predentin in vivo synthesis and maturation of type I, cxi(I) trimer, and type V collagens. Biochemistry 21, 2011-2015. 

In in vitro studies penicillamine inhibited angiotensin-con-verting enzyme (ACE) and carboxypeptidase (930). Penicillamine interferes with the functions of the copper-containing enzyme ceruloplasmin, and some of the penicillamine- and copper-containing complexes formed in vivo have a superoxide dismutase effect (931). In patients with scleroderma, penicillamine normalized collagen metabolism, by inhibiting beta-galactosidase activity (932). 

The well-known dose-related side effects include gingival hyperplasia (due to altered collagen metabolism), cerebellar-vestibular effects (nystagmus, vertigo, ataxia), behavioural changes (confusion, drowsiness, hallucinations), increased seizure frequency, gastrointestinal disturbances (nausea, anorexia), osteomalacia (due to reduced calcium absorption and increased vitamin D metabolism) and megaloblastic anaemia (due to reduced folate absorption). 

Pickrell, J.A., Harris, D.L., Hahn, F.F., Belasich, J.J., Jones, R.K. (1975). Biological alterations resulting from chronic lung irradiation III. Effect of partial Co thoracic irradiation upon pulmonary collagen metabolism and fractionation in Syrian hamsters, Radial Res. 62 133 4. 

At present, there are only hypothetical explanations for the cause of the contracture and its correlation with liver cirrhosis. A genetic factor probably plays a part, possibly also in combination with genuine epilepsy. Its more frequent incidence in alcoholic cirrhosis points to a disorder in collagen metabolism as a pathogenic factor. 

Nimni ME. Penicillamine and collagen metabolism. Scand J Rheumatol Suppl 1979 (28) 71-8. 

Todhunter R J, Fubini S L, Wootton J A M et al 1996 Effect of methylprednisolone acetate on proteoglycan and collagen metabolism of articular cartilage explants. Journal of Rheumatology 23 1207-1213... 

Phan, S.H., Thrall, R.S. and Williams, C. (1981). Bleomycin induced pulmonary fibrosis. Effect of steroid on lung collagen metabolism. Am. Rev. Respir. Dis. 124, 428-434. 

Russell, J.D., Russell, S.B. and Trupin, K.M. (1978). Differential effects of hydrocortisone on both growth and collagen metabolism of human fibroblasts from normal and keloid tissue. J. Cell. Physiol. 97, 221-223. 

In addition to collagen metabolism and scavenging ROS species to limit inflammation as noted above, ascorbate is required for the synthesis of norepinephrine from tyrosine, of carnitine from y-butyrobetaine whose immediate precursor is made by trimethylating lysine, for folinic acid production from folic acid. In the absence of ascorbate, the reduced activity of these processes slows nerve, energy and cardiac output, causingthe affected person to become exhausted and irritable. Scurvy is the old English word for ill-tempered. 

Other disorders of collagen metabolism, heritable or acquired, are discussed in Chapter 25. 

Cl. Cebecauer, L., and Trnavsk, K., The study of collagen metabolism in the human body. Vnitmi Lekar. 12, 339-344 (1966). 

F13. Frey, J., The value of the determination of senun hydroxyproline and urinary excretion hydroxyproline in the study of disturbances of collagen metabolism. J. Med. Lyon 46, 1547-1556 (1964). 

F8. Pil v, I. I., Collagen metabolism during the active phase of rheumatic fever in children. Pediatriya AZ, 47-49 (1964). 

Maternal toxicity was not described. A two-generation, one-dose study in rats showed altered lung collagen metabolism in fetuses of adults with life-time exposure (Kowalska 1988). The toxicological... 

A chronic-duration oral MRL was not derived for vanadium because of a lack of quantitative exposure data. Several chronic-duration oral studies using mice and rats exposed to vanadyl sulfate reported no significant changes in body weight (Schroeder and Balassa 1967 Schroeder and Mitchener 1975 Schroeder et al. 1970). However, these were not used because data was not available to determine the most sensitive end point for the derivation of a chronic-duration oral MRL. A two-generation, one-dose study of rats exposed to sodium metavanadate reported altered lung collagen metabolism in fetuses of adults with life-time exposure (Kowalska 1988). However, the... 

Jackson S, James M, Abrams P. The effect of oestradiol on vaginal collagen metabolism in postmenopausal women with genuine stress incontinence. BJOG 2002 109 339-344. 

Mansell JR Bailey AJ. Abnormal cancellous bone collagen metabolism in osteoarthritis. J Qin Invest 1998 101 1596-1603. 

Contraindicated in pregnancy and children, based on animal studies showing effects on collagen metabolism and cartilage development tendonitis (and tendon rupture) has occurred in adults. 

Although farm animals are regarded as quite tolerant to high zinc levels in the diet, horses, sheep, and cattle have been intoxicated by grazing on forage in the vicinity of zinc smelters. Horses are the most zinc-sensitive farm animals and react with lameness, osteochondrosis (possibly caused by an abnormal collagen metabolism due to an inhibition of lysyl oxidase followed by a zinc-provoked copper deficiency), and lymphoid hyperplasia of the spleen and lymph nodes (Kowalczyk et al. 1986). 

Gingival hyperplasia, apparently due to altered collagen metabolism, occurs in -20% of patients during chronic therapy and is probably the most common toxicity in children and young adolescents. It may be more frequent in individuals who also develop coarsened facial features. Toothless portions of the gums are not affected The condition does not necessarily require withdrawal of medication and can be minimized by good oral hygiene. 

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