Effects of plane of nutrition, growth hormone treatment and dietary polyunsaturated fat on mammary development were assessed in prepubertal ewe lambs. Ten lambs (15.6 kg initial body weight) were assigned to each of four treatment groups. Treatments included: (A) lambs given ad libitum access to a high-energy ration; (G) fed as group A but injected s.c. daily with bovine growth hormone (.08 mg/kg BW); (R) feed intake restricted to achieve a growth rate of about 120 g/d; and (S) given ad libitum access to a ration including a formaldehyde-protected sunflower seed supplement. Diets were isonitrogenous and isocaloric and were fed from about 7 to 22 wk of age. At slaughter, the udder was removed and divided into halves. One udder half was trimmed and the parenchyma was dissected from surrounding stroma for compositional analyses. Final body weight and rate of gain averaged 41.2, 42.8, 27.3 and 46.0 kg, and 251, 267, 112 and 311 g/d for groups A, G, R and S, respectively. In the same treatment order, mammary parenchymal weight averaged 15.3, 20.3, 14.2 and 25.6 g. Parenchymal dry, fat-free tissue and DNA content were 1.7, 2.5, 1.3 g and 12.6, 24.1, 10.4 and 18.8 mg, respectively. Mammary parenchymal development was stimulated by polyunsaturated fat but was not affected by plane of nutrition. Supplemental dietary lipid may promote mammogenesis in ruminants.

The influence of plane of nutrition, growth hormone (GH) treatment and dietary polyunsaturated fat on serum concentrations of GH and insulin (INS) and binding capacities of GH, INS and prolactin (PRL) in liver, mammary parenchyma and adipose tissue was assessed in prepubertal ewe lambs. Ten lambs were assigned to each of four treatment groups. Treatments included: (A) lambs with ad libitum access to a high-energy ration; (G) lambs fed as group A and treated with bovine GH (.08 mg/kg/d); (R) lambs with feed intake restricted to limit ADG to about 120 g; and (S) lambs with ad libitum access to a ration including formaldehyde-protected sunflower seed. Diets, all approximately isonitrogenous and isocaloric, were fed from about 7 to 22 wk of age. Weekly blood samples were collected during wk 6 to 14 of the trial. Averaged across sampling dates, mean serum concentrations of GH were elevated in G lambs (P less than .05) and INS concentrations differed in the order G greater than A greater than R = S (P less than .05). Crude membranes for binding assays were prepared from liver, mammary parenchyma and adipose tissue. Mean concentrations of GH receptors in liver and PRL receptors in mammary parenchyma were elevated in group S lambs (P less than .01). Dietary polyunsaturated fat increased the number of GH receptors in liver and PRL receptors in mammary parenchyma. Increased availability of receptors may mediate the stimulation of mammary growth observed in lambs fed polyunsaturated fat.

Non-alcoholic fatty liver disease (NAFLD) is a comorbidity of obesity, which gradually develops from hepatic steatosis into steatohepatitis (NASH) and eventually even into fibrosis or hepatic carcinoma. To date, there has been no specific and effective treatment for NAFLD. Sarcopoterium spinosum extract (SSE) was found to improve insulin sensitivity. Recognizing the intimate link between insulin resistance and NAFLD, the aim of this study was to investigate the effectivity of SSE in the prevention and management of NAFLD at various severities. SSE was given to high-fat diet (HFD)-fed mice (steatosis model) or to mice given a Western diet (WD) in the short or long term (NASH prevention or treatment, respectively). SSE reduced body weight accumulation, improved glucose tolerance and insulin sensitivity and prevented the development of hepatic steatosis. SSE also blocked the progression of liver disease toward NASH in a dose-dependent manner. The expression of genes involved in lipid metabolism, inflammation, and antioxidant machinery was regulated by SSE in both models of steatosis and NASH development. However, SSE failed to reverse the hepatic damage in the advanced model of NASH. In summary, SSE might be considered as a botanical supplement for the prevention and treatment of hepatic steatosis, and for slowing the deterioration toward NASH.

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Objective Chronic stress promotes obesity and metabolic comorbidities. The ability of individuals to cope with stress may serve as an important parameter in the development of obesity‐related metabolic outcomes. The aim of this study was to clarify whether differences in stress response affect metabolic health under obesity. Methods The study was performed in a selectively bred mouse model of social dominance (Dom) and submissiveness (Sub), which exhibit stress resilience or vulnerability, respectively. Mice were given a high‐fat diet (HFD) or standard diet, followed by physiological, histological, and molecular analyses. Results The HFD caused hyperleptinemia, glucose intolerance, insulin resistance, steatosis of the liver and pancreas, and brown adipose tissue whitening in Sub mice, whereas Dom mice were protected from these consequences of the HFD. The HFD increased circulating levels of interleukin (IL)‐1β and induced the expression of proinflammatory genes in the liver and in epididymal white adipose tissue of Sub mice, with no changes in Dom mice. The Cox2 inhibitor celecoxib (15 mg/kg/d) reduced serum IL‐1β, improved glucose tolerance and insulin sensitivity, and prevented hepatic and brown adipose tissue whitening in HFD‐fed Sub mice. Conclusions The extent of stress resiliency is associated with inflammation and contributes to population heterogeneity in the development of healthy or unhealthy obesity.

Histological and pathological alterations of ovine mammary parenchyma xenografted into cyclosporine-treated mice were studied. Forty-two mature, virgin female mice were assigned randomly to one of four treatments: 1) control, 2) control + estrogen/progesterone, 3) cyclosporine, and 4) cyclosporine + estrogen/progesterone. All mice received two subcutaneous mammary tissue explants taken from an estrogen and progesterone-primed ewe. After 3, 7, 14, 21, and 35 d, mice were killed and tissue was removed for an evaluation of epithelial morphology on a scale from 1 (poor) to 5 (excellent). Leukocyte type and number were determined in subepithelial stroma. The mean epithelial score for tissue collected on d 7 and d 21 were higher (P less than .05) for cyclosporine treatments (3.0) than for controls (1.6). Scores also were greater (P less than .01) when cyclosporine was combined with estrogen and progesterone than when cyclosporine was the sole treatment (3.8 vs 2.3). Epithelial scores for tissue recovered from mice given cyclosporine and steroids up to 35 d were not different from those of explants fixed at zero time. However, scores were lower (P less than .05) for three of five time periods for explants recovered from mice given cyclosporine alone. Lymphocyte number was higher (P less than .07) in controls (66) than in mice given cyclosporine and steroids (13 per field). The correlation between lymphocyte number and epithelial score was -.55. These results indicate that ovine mammary tissue xenografted into mice treated with cyclosporine can maintain a normal histological structure for an extended period of time.