Temperature control of hypertensive rats during moderate exercise in warm environment

The control of body temperature in Spontaneously Hypertensive Rat (SHR) subjected to exercise in warm environment was investigated. Male SHR and Wistar rats were submitted to moderate exercise in temperate (25°C) and warm (32°C) environments while body and tail skin temperatures, as well as oxygen consumption, were registered. Total time of exercise, workload performed, mechanical efficiency and heat storage were determined. SHR had increased heat production and body temperature at the end of exercise, reduced mechanical efficiency and increased heat storage (p < 0.05). Furthermore, these rats also showed a more intense and faster increase in body temperature during moderate exercise in the warm environment (p < 0.05). The lower mechanical efficiency seen in SHR was closely correlated with their higher body temperature at the point of fatigue in warm environment (p < 0.05). Our results indicate that SHR exhibit significant differences in body temperature control during moderate exercise in warm environment characterized by increased heat production and heat storage during moderate exercise in warm environment. The combination of these responses result in aggravated hyperthermia linked with lower mechanical efficiency

Meniscal allograft transplantation in rabbit

This study evaluated the technique for meniscal allograft transplantation using allografts preserved in glycerin 98% in rabbits. Euthanasia was performed at 70 days to compare the transplanted (TM1 to TM16) versus the contralateral meniscus (OM1 to OM16). Sixteen menisci, 8 transplanted and 8 contralateral, were submitted to gross examination, histomorphometric analysis for identification and quantification of cellular type, and for quantification and distribution of collagen fibers. A revascularization study was conducted in all of the other samples. Lengths of the OM varied from 0.9 to 1.0 cm and two TM were smaller. All TM were completely attached to the synovial membrane, except for one case that presented partial fixation. Both, TM and OM had similar amounts of chondrocytes, fibroblasts and fibrocytes, and at the horns, chondrocytes were predominant. The collagen fibers in TM were well organized throughout the body, and disorganized at the horns. These fibers in OM were organized. The amounts of collagen type I and III, and the vascularization of the perimeniscal tissue and of the edge were similar in OM and TM. These results demonstrated graft integration and thus this transplantation technique and preservation method may be recommended

Meniscal allograft transplantation in rabbit

This study evaluated the technique for meniscal allograft transplantation using allografts preserved in glycerin 98% in rabbits. Euthanasia was performed at 70 days to compare the transplanted (TM1 to TM16) versus the contralateral meniscus (OM1 to OM16). Sixteen menisci, 8 transplanted and 8 contralateral, were submitted to gross examination, histomorphometric analysis for identification and quantification of cellular type, and for quantification and distribution of collagen fibers. A revascularization study was conducted in all of the other samples. Lengths of the OM varied from 0.9 to 1.0 cm and two TM were smaller. All TM were completely attached to the synovial membrane, except for one case that presented partial fixation. Both, TM and OM had similar amounts of chondrocytes, fibroblasts and fibrocytes, and at the horns, chondrocytes were predominant. The collagen fibers in TM were well organized throughout the body, and disorganized at the horns. These fibers in OM were organized. The amounts of collagen type I and III, and the vascularization of the perimeniscal tissue and of the edge were similar in OM and TM. These results demonstrated graft integration and thus this transplantation technique and preservation method may be recommended