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Compared with young mice, old mice infected with influenza virus have significantly higher pulmonary viral titres, although these can be reduced significantly with dietary vitamin E supplementation. T helper 1 (Th1) cytokines, especially interferon-gamma (IFN-gamma), play an important role in defending against influenza infection. However, there is an age-associated loss of Th1 cytokine production. Prostaglandin E2 (PGE2) production, which increases with age, can modulate the T helper cell function by suppressing Th1 cytokine production. To investigate the mechanism of vitamin E supplementation on reduction of influenza severity in old mice, we studied the cytokine production by splenocytes, and PGE2 production by macrophages (Mphi), in young and old C57BL mice fed semipurified diets containing 30 (control) or 500 parts per million (ppm) (supplemented) vitamin E for 8 weeks, and then infected with influenza A/PC/1/73 (H3N2). Old mice fed the control diet had significantly higher viral titres than young mice; old mice fed the vitamin E-supplemented diet had significantly lower pulmonary viral titres than those fed the control diet (P = 0.02 and 0.001 for overall age and diet effect, respectively). Following influenza infection, interleukin (IL)-2 and IFN-gamma production was significantly lower in old mice than in young mice. Vitamin E supplementation increased production of IL-2 and IFN-gamma in old mice; higher IFN-gamma production was associated with lower pulmonary viral titre. Old mice fed the control diet showed significantly higher lipopolysaccharide (LPS)-stimulated Mphi PGE2 production than old mice fed the vitamin E diet or young mice fed either diet. There was no significant age difference in IL-6, IL-1beta, or tumour necrosis factor-alpha (TNF-alpha) production by splenocytes. Young mice fed the vitamin E-supplemented diet had significantly lower IL-1beta (day 7) and TNF-alpha production (day 5) compared with those fed the control diet. Old mice fed the vitamin E-supplemented diet had significantly lower TNF-alpha production (day 2) than those fed the control diet. Our results indicate that the vitamin E-induced decrease in influenza viral titre is mediated through enhancement of Th1 cytokines, which may be the result of reduced PGE2 production caused by vitamin E.

100 pieces of renal tissue from 4 patients with renal artery stenosis were studied histologically. Juxtaglomerular cells were found not only in the region close to the glomerulus but also in the proximal 2/3 of the afferent arteriole of the glomerulus, but not in the interlobular arterioles. In the cytoplasm of juxtaglomerular cells, three kinds of granules were found: crystalline granules (immature), the round or ovoid granules (mature), and the lobulated granules (fusion). Renin was synthesized in the rough endoplasmic reticulum and packaged in the Golgi complex. Electron microscopic findings suggested that the secretory microvesicles were produced on the surface of Golgi complex. They fused to form primary crystalline granules, which were enlarged by renin supplied by transportation vesicles and finally formed typical crystalline granules. The mature renin granules (round or ovoid) moved toward the periphery of the cytoplasma. Their limiting membranes on the side toward the basement membrane disintegrated and formed microvesicular bodies passing through the periplasm, and the basement membrane and were discharged into the interstitial matrix.