ABSTRACT
The histological and histochemical appearance of murine fetal tibiae was studied in order to furnish the morphological background for biochemical investigations on in vitro cultures of these organs, used as an experimental model for the study of drug influences on metabolic processes of mesenchymal tissues. Freshly excised tibiae until the 14th day of gestation showed solely cartilagenous structures; first signs of calcification were found after 15 days of gestation and ossification of the diaphysis proceeds until the 17th day. A comparison of tibiae explants excised on the 17th day of gestation and cultured for 6 days in vitro with freshly excised tibiae of the same age (17 days) indicates a continuous growth of the explants in vitro without any signs of degenerative processes which could be due to the culture conditions.
Subject(s)
Tibia/embryology , Animals , Female , Gestational Age , Histocytochemistry , Mice , Organ Culture Techniques , Pregnancy , Tibia/analysisABSTRACT
Cultures of murine embryonic bone explants were studied regarding their use as experimental model for the investigation of drug effects on metabolic processes of mesenchymal tissues. Embryonic tibiae excised on the 17th day of gestation and grown in a liquid medium for 6 days as organ cultures appeared particularly suited for this purpose. The planimetrically estimated size of the explants increased during this period in the mean by 40.7% and their DNA-content rose by 67.5%. After 6 days of incubation in vitro the mean DNA-content was about 2.5 micrograms/mg wet weight and the mean uronic acid content 10 micrograms/mg wet weight. Using dexamethasone, oxyphenbutazone, acetyl salicylic acid, sodium aurothiomalate and sodium pentosanpolysulfate as test drugs clear differences in the action on the determined parameters (explant growth, DNA- and uronic acid-content, glycosaminoglycan secretion of the explants) could be demonstrated.
Subject(s)
Bone and Bones/metabolism , Fetus/metabolism , Aging , Animals , Bone and Bones/drug effects , Bone and Bones/embryology , Culture Media , DNA/metabolism , Extraembryonic Membranes/metabolism , Female , Glycosaminoglycans/metabolism , Models, Biological , Organ Culture Techniques , Pregnancy , Time FactorsABSTRACT
The histological investigation of cultured, embryonic tibia explants of NMRI-mice showed, after a six day period, that incubation concentrations of Flufenamic acid, SP54 (a Pentosanopolysulphate), and Dexamethasone (9alpha-Fluor-16-beta-Methyl-Prednisolone) predominantly induced resorptive and degenerative processes, in different degrees, affecting cartilage and bone matrix. In the experiments with Flufenamic acid and Dexamethasone, the degenerative processes were found to be accompanied by the inhibition of the synthesis of cartilage matrix. The investigations with SP54, on the other hand, showed a medium increase of cartilage matrix.
