The effects of dietary polyunsaturated fatty acids (PUFA) on ex vivo bone prostaglandin E(2) (PGE(2)) production and bone formation rate were evaluated in rats. Weanling male Sprague-Dawley rats were fed AIN-93G diet containing 70 g/kg of added fat for 42 d. The dietary lipid treatments were formulated with safflower oil and menhaden oil to provide the following ratios of (n-6)/(n-3) fatty acids: 23.8 (SMI), 9.8 (SMII), 2.6 (SMIII), and 1.2 (SMIV). Ex vivo PGE(2) production in liver homogenates and bone organ cultures (right femur and tibia) were significantly lower in rats fed diets with a lower dietary ratio of (n-6)/(n-3) fatty acids than in those fed diets with a higher dietary ratio. Regression analysis revealed a significant positive correlation between bone PGE(2) and the ratio of arachidonic acid (AA)/eicosapentaenoic acid (EPA), but significant negative correlations between bone formation rate and either the ratio of AA/EPA or PGE(2) in bone. Activities of serum alkaline phosphatase isoenzymes, including the bone-specific isoenzyme (BALP), were greater in rats fed a diet high in (n-3) or a low ratio of (n-6)/(n-3), further supporting the positive action of (n-3) fatty acids on bone formation. These results demonstrated that the dietary ratio of (n-6)/(n-3) modulates bone PGE(2) production and the activity of serum BALP in growing rats.

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The results of clinical and pulmonary functional evaluation of 24 cats with bronchopulmonary disease and 15 healthy cats are presented. Affected cats had historical evidence of excessive reflexes (coughing, sneezing); physical evidence of airway secretions (crackles), obstruction (wheezing), and increased tracheal sensitivity; radiographic evidence of bronchial and interstitial lung disease; and cytological evidence of airway inflammation or mucous secretions. Bacterial isolates from healthy and affected cats were predominantly Gram-negative rods, indicating that bronchi of cats are not always sterile and that normal flora should be considered in interpreting cultures from cats with suspected bronchopulmonary disease. Cats were grouped according t o relative disease severity based on scored historical, physical, and radiographic abnormalities. The mean (? standard deviation) baseline lung resistance measurement in healthy cats was 28.9 cm H,O/L/s (?6.2 cm H,O/L/s), whereas in mildly, ronchopulmonary disease in the cat represents a group B of poorly understood airway and alveolar space disorder^.'.^ Clinical signs are thought to be due, in part, to underlying airway obstruction. Factors contributing to the development of airway obstruction presumably include development of airway inflammation and mucosal edema, development of airway smooth muscle hypertrophy and constriction, and excessive production or retention of pulmonary secretions. Actual measurements of pulmonary function in cats with bronchopulmonary disease have not been available previously. We obtained pulmonary functional measurements from cats with naturally occurring disease and from clinically healthy cats in an attempt to better assess the presence and degree of airway obstruction in affected cats. Healthy cats were defined as subjects with no known historical or physical findings indicating respiratory disease. A complete clinical database (including historical, physical, and radiographic assessments) was obtained for all cats and also was used to quantify the relative clinical severity of respiratory disease. Measurements of baseline lung resistance (RL) and dynamic lung compliance (Cdyn) were obtained, and airway cytological and microbial culture data were collected. Whenever possible, evaluation also included IV administration of a bronchodilator (BD) to assess reversibility of the airway obstruction, or alternatively, an aerosolized bronchoprovocative challenge to assess the ease with which airway obstruction could be induced (ie, the degree of airway responsiveness [AR] present). Materials and Methods CatsTwenty-four cats with naturally occurring bronchopulmonary disease and 15 clinically healthy cats were evaluated in a cross-sectional study conducted over a 1-year period. The cats with bronchopulmonary disease included 21 cats presented or referred to the University of Illinois Veterinary Medicine Teaching Hospital (UIVMTH) for a variety of clinical signs suggestive of lower respiratory disease. One