High-fat diet induced changes in lumbar vertebra of the male rat offsprings

In obesity, bone marrow adiposity increases and proinflammatory cytokines excretion activates RANK/RANKL/OPG system, which leads to increased bone resorption. The aim of this study was to analyze trabecular and cortical bone parameters in animals exposed to the high-fat diet in utero and after lactation. Skeletal organ of interest was the fifth lumbar vertebra, which is not exposed to biomechanical loading in rats. Further aims were to determine TNF-α and IL-6 serum concentrations, and the intensity of the TNF-α immunohistochemical staining in the bone marrow. Ten female Sprague Dawley rats, nine weeks old, were randomly divided in two groups and fed either standard laboratory chow or food rich in saturated fatty acids during five weeks, and then mated with genetically similar male subjects. After birth and lactation male offsprings from both groups were divided in four subgroups depending on the diet they were fed until twenty-two weeks of age. The highest cholesterol and triglyceride concentration were found in both groups of offsprings fed with high-fat diet. The lowest trabecular bone volume, lowest trabecular number and highest trabecular separation were found in offsprings fed with high-fat diet of mothers on standard laboratory chow. The same group of offsprings was also characterized by the highest intensity of TNF-α immunostaining in the bone marrow and the highest TNF-α serum concentration, which suggest that this proinflammatory cytokine has interfered with bone metabolism, possibly by stimulation of bone resorption, which led to inadequate trabecular bone development and bone modeling of the fifth lumbar vertebra.