The cooperation of adipocytes and stromal cells in the secretion of prostaglandins by rat adipose tissue is not influenced by diet

This study examined the influence of dietary essential fatty acids on the cooperativity of isolated adipocytes and stromal-vascular cells in the biosynthesis of prostaglandins. Sprague-Dawley rats were fed either a diet rich in essential fatty acids (20% corn oil) or a diet poor in essential fatty acids (20% tallow) for 4 wk. Preparations containing primarily adipose cells (adipocytes) or stromal-vascular cells (nonfat cells) were obtained from epididymal fat pads by collagenase digestion and repeatedly washed. Prostaglandin production was evaluated in basal and epinephrine-stimulated media after incubation with either adipocytes or adipocytes + nonfat cells. Prostaglandin E2 and prostacyclin production by adipocytes + nonfat cells was dose-dependent with epinephrine stimulation in cells from rats fed both diets. Both prostaglandin E2 and glycerol release in response to epinephrine (10-100 micromol/L) stimulation from adipocytes or from adipocytes + nonfat cells were significantly higher for cells from corn oil-fed rats than for cells from tallow-fed rats. Regardless of dietary treatment, epinephrine-stimulated prostaglandin E2 and prostacyclin release from adipocytes + nonfat cells was much greater than from adipocytes. These results suggest that a diet high in essential fatty acids precipitates a higher prostaglandin E2 secretion and that nonfat cells potentiate the secretion of prostaglandin E2 and prostacyclin by adipocytes regardless of diet.