Low-intensity treadmill exercise-related changes in the rat stellate ganglion neurons.

Stellate ganglion (SG) represents the main sympathetic input to the heart. This study aimed at investigating physical exercise-related changes in the quantitative aspects of SG neurons in treadmill-exercised Wistar rats. By applying state-of-the-art design-based stereology, the SG volume, total number of SG neurons, mean perikaryal volume of SG neurons, and the total volume of neurons in the whole SG have been examined. Arterial pressure and heart rate were also measured at the end of the exercise period. The present study showed that a low-intensity exercise training program caused a 12% decrease in the heart rate of trained rats. In contrast, there were no effects on systolic pressure, diastolic pressure, or mean arterial pressure. As to quantitative changes related to physical exercise, the main findings were a 21% increase in the fractional volume occupied by neurons in the SG, and an 83% increase in the mean perikaryal volume of SG neurons in treadmill-trained rats, which shows a remarkable neuron hypertrophy. It seems reasonable to infer that neuron hypertrophy may have been the result of a functional overload imposed on the SG neurons by initial posttraining sympathetic activation. From the novel stereological data we provide, further investigations are needed to shed light on the mechanistic aspect of neuron hypertrophy: what role does neuron hypertrophy play? Could neuron hypertrophy be assigned to the functional overload induced by physical exercise?

Correlação entre ruptura de ligamento cruzado cranial e lesão de meniscomedial em cães / Correlation between cranial cruciate ligament rupture and meniscal tears in dogs

O presente trabalho correlacionou o tempo de ruptura do ligamento cruzado cranial (RLCCr) à lesão em menisco medial e ao tipo de lesão observada em cães tratados por estabilização dinâmica (osteotomias) ou estática (sutura fabelo-tibial). Este estudo retrospectivo avaliou os registros de 104 cães (117 joelhos). As osteotomias foram realizadas em 98 articulações, a sutura fabelo-tibial em 15 joelhos e, em 4 joelhos, foi realizada apenas artrotomia exploratória. A média de idade foi 4,5 anos, 41% dos cães eram machos e 59%, fêmeas e a média da massa corporal foi 32,7kg. Os tipos de lesão do menisco medial observados foram: tipo 1, 2, 3, 4, 6, 7 e associações dos tipos 1-4, 1-6 e 1-7. O tipo 1 foi o mais prevalente, sendo responsável por 32,5% dos casos. Não foram encontradas correlações entre a presença ou não de lesão de menisco medial e o tempo de ocorrência da RLCCr e entre o tipo de lesão de menisco medial e o tempo de RLCCr.

The study correlated the time of the cranial cruciate ligament rupture (CCLR) with medial meniscal tears and the type of injury seen in dogs treated with dynamic stabilization (osteotomies) or static (fabellotibial suture). This retrospective study evaluated the records of 104 dogs (117 stifles). The osteotomies were performed in 98 stifles, fabellotibial suture in 15 stifles and exploratory arthrotomy was perform in 4 stifles. The average age was of 4.5 years, 41% of the dogs were male and 59% female and the mean body mass was of 32.7kg. The medial meniscal tears observed were: type1, 2, 3, 4, 6, 7 and associations of types1-4, 1-6 and 1-7. Type 1 was the most prevalent, accounting for 32.5%of cases. No correlation was found between the presence or absence of medial meniscus injury and the time of occurrence of CCLR and between the type of medial meniscal tears and CCLR time.