Bone formation, rats, effect

The results of experiments conducted by MacKenzie and McCollum (15) indicate that the effect of dietary oxalic acid on the rat depends on the composition of the diet. There was no effect on rate of growth or calcium excretion of 50 g rats fed for 10 weeks a diet containing 0.6% calcium, 0.7% phosphorus, and optimum vitamin D, when levels of potassium oxalate up to 2.5% were fed. The percent bone ash on the 2.5% oxalate diet was somewhat lower than on the control diet. On a 0.35% calcium, 0.35% phosphorus, and vitamin D-free diet, 1.7% potassium oxalate resulted in restricted growth and bone formation of weanling rats. 

LGD-5552, a compound whose structure has not been published yet, binds efficiently to GR and has a dissociated profile in vitro. It has been applied in different inflammation models in rodents showing efficacy comparable to that of prednisolone. In contrast to the steroid, it does not increase the arterial blood pressure in a rat hypertension model, and its negative effects on bone resorption, longitudinal mid-femur and periosteal bone formation are less pronounced than after treatment with prednisolone [70]. 

Baud CA, Very JM, Courvoisier B (1988) Biophysical study of bone mineral in biopsies of osteoporotic patients before and after long-term treatment with fluoride. Bone 9 361-365 Baylink D, Wergedal J, Stauffer M, Rich C (1970) Effects of fluoride on bone formation, mineralization, and resorption in the rat. In Fluorine in Medicine. Vischer T (ed) Hans Huber Publisher, Bern, p 37-69 Berthet-Columinas C, Miller A, White SW (1979) Structural study of the calcifying collagen in tuikey leg tendons. J Mol Biol 134 431-445... 

In rats fed diets containing 0.1,0.5,1.0, or 2.0% methyl salicylate for 2 years, animals fed the highest dose did not survive past 49 weeks. At the 1% level, growth rates were considerably reduced and enlargement of male testes and female hearts and kidneys were noted. Excess cancellous bone formation was seen at the 2.0,1.0, and 0.5% levels (Webb and Hansen 1963). Another 2-year feeding study revealed no adverse effects, including bone changes, at dietary levels up 0.21% of methyl salicylate (Packman et al. 1961). 

In female rats fed a mixture of valepotriates, 6 to 24 mg/ kg daily, for 30 days before pregnancy or on days 1 through 19 of pregnancy, no effects on fertility or signs of fetotoxicity were observed. An increased number of fetuses with slowed bone formation were observed with the higher doses (12 and 24 mg/kg) of valerian (Tufik et al. 1994). 

Goodman WG, Gdligan J Horst R. (1984). Short term aluminum administration in the rat Effects on bone formation and relationship to renal osteomalacia. J CUn Invest 73, 171. 

Li B, Yoshii T, Hafeman AE, Nyman JS, Wenke JC, Guelcher SA. The effects of rhBMP-2 released from biodegradable polyurethane/microsphere composite scaffolds on new bone formation in rat femora. Biomaterials 2009 30(35) 6768-6779. 

Besides the mere structural design of bone scaffolds, the use of proteins or peptides guiding cellular behavior is also widely applied due to the large clinical information from therapies of bone fractures. For example, lin et al. investigated the effect of a BMP-2-related peptide incorporated in a PLGA-(PEG-ASP)n copolymer on bone formation in vitro using BMSCs and in vivo ectopic bone formation in Wistar rats. The modified composites showed much better in vitro results compared to tmmodified controls in terms of cell attachment, proliferation. 

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