Tetracyclines have been reported to inhibit bone resorption and intensify bone formation. The aim of the present study was to investigate the effects of doxycycline (20 mg/kg PO daily for 28 days) on bone mechanical properties in bilaterally ovariectomized and sham-operated rats. The experiment was carried out on 3-month-old Wistar rats. Mechanical properties of the whole femur (extrinsic stiffness, ultimate and breaking load, deformation caused by applied load) and the femoral neck (load at fracture) as well as bone mass and bone mineral content in the tibia, femur, and L4 vertebra were examined. Bilateral ovariectomy resulted in decreases in bone mineral content/bone mass ratio and worsening of mechanical properties of the femoral neck. The changes were counteracted by doxycycline. Doxycycline reversed the effect of ovariectomy on load at fracture of the femoral neck. Doxycycline did not significantly affect the mechanical properties of bones in the sham-operated rats.

Long-term administration of heparin can be associated with development of osteoporosis. The present study was carried out to compare the effects of standard heparin and two low-molecular-weight heparins (nadroparin and enoxaparin) on bone mechanical properties in rats. The experiment was conducted on 3-month-old female Wistar rats. Standard heparin was administered in doses of 1000 or 2000 IU/kg sc daily, nadroparin and enoxaparin were administered in doses of 1000 or 2000 anti-Xa IU/kg sc daily, for 28 days. Bone mass, length, diameter, mineral content and mechanical properties of the whole femur (extrinsic stiffness, ultimate and breaking load, deformation caused by the applied load) and the femoral neck (load at fracture) were examined. Standard heparin (2000 IU/kg sc daily) weakened the femoral neck. Enoxaparin and the higher doses of standard heparin and nadroparin induced similar unfavourable changes in mechanical properties of the whole femur; the changes were noticeable the most after administration of enoxaparin.

Azinyl Sulfides.Part 52. 1,4-Dihydro-1-methyl-4-thioxo-3quinolinesulfonamides.-A number of the title sulfonamides (III) are prepared and evaluated for their antihypertensive activity. -(SKRZYPEK, L.; FOLWARCZNA, J.; JANIEC, W.; KACZMARCZYK-SEDLAK, I.; MASLANKIEWICZ, A.; PYTLIK, M.; Pol.

No abstract

Sulfur metabolism was traced in experimental investigations on rats, and the importance of the method for neutralizing sulfur dioxide with ammonia was estimated.The animals were exposed to 53502 by means of inhalation, and radioactivity in several organs at different periods of exposure was traced.Sulfur incorporation into proteins and mucopolysaccharides, as well as elimination of isotope with urine and feces at different periods of time after exposure, were also determined The second group of animals was exposed to the products of 53502 neutralized by ammonia; after performing identical investigations it was found that the use of ammonia to neutralize sulfur dioxide in the air decreased the amount of sulfur which could pass into the organism through the breathing of air contaminated by 50 2 The use of 53502 neutralized by ammonia brings about a faster elimination of sulfur from the organism.