Blood flow and mineral content of the tibia of female and male rats: changes following castration and/or administration of estradiol or testosterone.
We studied changes in the local circulation and mineralization of the rat tibia under different experimental conditions. Four experiments were performed on a total of 155 female and male rats: after oophorectomy (OOX) or orchidectomy (ORX), after the administration of estradiol benzoate (EB, Agofollin Depot, 1 mg/rat once a week or 5 mg/kg body weight once every 5 days for 4 weeks), or after the administration of testosterone (T, Agovirin Depot, 25 mg/kg body weight once every 5 days for 4 weeks). We estimated 85Sr-microsphere uptake and blood flow in the tibia, density of the tibia, and ash weight per bone volume unit. The scheme of the experiments was uniform: experiment A--females--controls, OOX, EB, OOX + EB; experiment B--males--controls, ORX, EB, ORX + EB; experiment C--females--controls, OOX, T, OOX + T; experiment D--males--controls, ORX, T, ORX + T. A sham operation was performed on the animals in the uncastrated groups. The results showed that OOX and ORX stimulated the uptake of 85Sr-microspheres and bone blood flow and reduced both bone density and ash weight, whereas T inconstantly and EB constantly reduced 85Sr-microsphere uptake and bone blood flow and increased bone density and ash weight in both sham-operated and castrated animals. The described changes in the bone blood flow and mineral content under the given experimental conditions suggest a relation in the regulations of both processes, a possible association with resorption of bone, and the importance of the circulation of blood in the metabolism of bone tissue.
Kapitola
J
J
Laboratory for Endocrinology and Metabolism, 1st Medical Faculty, Charles University, Prague, Czech Republic.
Kubícková
J
J
Andrle
J
J
D000818:Animals; D015519:Bone Density / Q000187:drug effects / Q000502:physiology*; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D008297:Male; D009919:Orchiectomy; D010053:Ovary / Q000502:physiology*; D051381:Rats; D012039:Regional Blood Flow; D013737:Testis / Q000502:physiology*; D013739:Testosterone / Q000494:pharmacology*; D013977:Tibia / Q000098:blood supply* / Q000187:drug effects / Q000502:physiology
D013739:Testosterone; D004958:Estradiol