Biomaterial Database

Lack of evidence for rickets in the osteopetrotic rat mutation, toothless. 1994

M F Seifert

Department of Anatomy, Indiana University School of Medicine, Indianapolis.

A common, but paradoxic, feature among osteopetrotic human infants is the presence of rickets. This disorder of mineralization is manifested radiographically and histologically by increased growth plate cartilage and hypertrophic cell zone thickness and excess metaphyseal osteoid and biochemically by decreased serum calcium and phosphorus concentrations. Rickets has also been reported in two osteopetrotic animal mutations, the osteosclerotic (oc) mouse and the toothless (tl) rat. Although the phenotypic expression of the rachitic lesion in the oc mouse closely resembles that in affected humans, the results of the present study show that the lesion in the tl rat does not. Compared with normal littermates, histologic and morphometric analyses of tibial growth plate cartilage in tl rats up to 5 weeks of age showed age-related increases in thickness of the proliferative cell zone and decreases in thickness of the hypertrophic cell zone that were most apparent within the central, but not lateral, regions of the growth plate and areas of acellularity and failure of chondrocytes to transform synchronously from proliferative cell to hypertrophic cell phenotypes. Femoral ash content, composition, and accretion rates did not differ from those in normal rats during the first 5 weeks of life. These findings do not support the rachitic nature of the cartilage lesion in the tl rat. Rather, a chondrodysplastic disorder is suggested, which more closely resembles the cartilage defect present in this mutation.

UI	MeSH Term	Description	Entries
D007015	Hypophosphatemia, Familial	An inherited condition of abnormally low serum levels of PHOSPHATES (below 1 mg/liter) which can occur in a number of genetic diseases with defective reabsorption of inorganic phosphorus by the PROXIMAL RENAL TUBULES. This leads to phosphaturia, HYPOPHOSPHATEMIA, and disturbances of cellular and organ functions such as those in X-LINKED HYPOPHOSPHATEMIC RICKETS; OSTEOMALACIA; and FANCONI SYNDROME.	Diabetes, Phosphate,Familial Hypophosphatemia,Hyperphosphaturia,Phosphate Diabetes,Phosphaturia,Familial Hypophosphatemias,Hypophosphatemias, Familial
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D010022	Osteopetrosis	Excessive formation of dense trabecular bone leading to pathological fractures; OSTEITIS; SPLENOMEGALY with infarct; ANEMIA; and extramedullary hemopoiesis (HEMATOPOIESIS, EXTRAMEDULLARY).	Albers-Schoenberg Disease,Marble Bone Disease,Osteosclerosis Fragilis,Albers-Schonberg Disease,Albers-Schonberg Disease, Autosomal Dominant,Albers-Schönberg Disease,Autosomal Dominant Osteopetrosis Type 2,Congenital Osteopetrosis,Marble Bones, Autosomal Dominant,Osteopetrosis Autosomal Dominant Type 2,Osteopetrosis, Autosomal Dominant 2,Osteopetrosis, Autosomal Dominant, Type II,Osteosclerosis Fragilis Generalisata,Albers Schoenberg Disease,Albers Schonberg Disease,Albers Schonberg Disease, Autosomal Dominant,Albers Schönberg Disease,Disease, Albers-Schoenberg,Disease, Albers-Schonberg,Disease, Albers-Schönberg,Disease, Marble Bone,Osteopetroses,Osteosclerosis Fragilis Generalisatas
D010641	Phenotype	The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.	Phenotypes
D004195	Disease Models, Animal	Naturally-occurring or experimentally-induced animal diseases with pathological processes analogous to human diseases.	Animal Disease Model,Animal Disease Models,Disease Model, Animal
D005269	Femur	The longest and largest bone of the skeleton, it is situated between the hip and the knee.	Trochanter,Greater Trochanter,Lesser Trochanter,Femurs,Greater Trochanters,Lesser Trochanters,Trochanter, Greater,Trochanter, Lesser,Trochanters,Trochanters, Greater,Trochanters, Lesser
D006132	Growth Plate	The area between the EPIPHYSIS and the DIAPHYSIS within which bone growth occurs.	Cartilage, Epiphyseal,Epiphyseal Cartilage,Epiphyseal Plate,Cartilages, Epiphyseal,Epiphyseal Cartilages,Epiphyseal Plates,Growth Plates,Plate, Epiphyseal,Plate, Growth,Plates, Epiphyseal,Plates, Growth
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013977	Tibia	The second longest bone of the skeleton. It is located on the medial side of the lower leg, articulating with the FIBULA laterally, the TALUS distally, and the FEMUR proximally.	Tibias
D016388	Tooth Loss	The failure to retain teeth as a result of disease or injury.	Loss, Tooth