A study of the novel anti-inflammatory agent florifenine topical anti-inflammatory activity and influence on arachidonic acid metabolism and neutrophil functions

We have evaluated the effects of the novel anti-inflammatory agent florifenine, 2-(1-Pyrrolidinyl)ethyl N-[7-(trifluoromethyl)-4-quinolyl]anthranilate, on topical inflammation in mice, free radical-mediated reactions, arachidonic acid metabolism and some neutrophil functions. Topical administration of florifenine produced dose-related anti-inflammatory activity in 12-O-tetradecanoylphorbol 13-acetate (TPA)-induced ear oedema and with a lower potency, in the response induced by arachidonic acid (AA). Florifenine also inhibited neutrophil migration and PGE₂ content in the inflammed ears. In human whole blood, florifenine was a potent and selective inhibitor of TXB₂ generation. This anti-inflammatory agent did not exert antioxidant effects but inhibited elastase release in human neutrophils without affecting superoxide anion generation. Florifenine administration to mice dose-dependently inhibited leukocyte migration and PGE₂ levels in the air pouch inflammation induced by zymosan. These results demonstrate the topical anti-inflammatory activity of florifenine and provide a basis for understanding the mechanisms involved in the inhibitory effects of this agent on inflammatory responses.     

Dietary chloride as a possible determinant of the severity of exercise-induced asthma

Dietary sodium chloride (NaCl) has been shown to alter the severity of exercise-induced asthma, but it is not known if the sodium and chloride ions have independent effects in this regard. The hypothesis tested in the present study was that both a low sodium, low chloride diet and a high sodium, low chloride diet would improve post-exercise pulmonary function in subjects with exercise-induced asthma (EIA) compared to a normal NaCl diet (NSD); but that neither of these diets would have an effect on post-exercise pulmonary function in control (non-EIA) subjects. Eight subjects who suffered from EIA and eight subjects who did not (control) took part in a double-blind crossover study. Pre- and post-exercise pulmonary function was assessed after 2 weeks on a NSD, a low NaCl diet (LSD, low sodium, low chloride) or a sodium bicarbonate diet (NaHCO₃ diet, high sodium, low chloride). A 1 week washout period occurred between diets. Altering dietary sodium or chloride had no effect on pre-exercise (baseline) pulmonary function in either group or on post-exercise pulmonary function in control subjects. However, both the LSD and the NaHCO₃ diet lessened the deterioration in post-exercise pulmonary function in EIA subjects. Comparing results from pre- to post-exercise, forced expiratory volume in 1 s (FEV₁) at 15 min post-exercise differed significantly (P<0.05) between diets [mean (SEM) 7 (4)% on the LSD, 14 (4)% on the NaHCO₃ diet, and 19 (2)% on the NSD]. Similar patterns were observed for forced vital capacity (FVC), forced expiratory flow rate at 25%–75% FVC and peak expiratory flow rate. The NaHCO₃ diet lessened the deterioration of post-exercise pulmonary function, but not to the extent of LSD. These data suggest that both sodium and chloride contribute to the worsening of EIA symptoms seen after consuming a normal or high NaCl diet. Electronic Publication     

花生四烯酸产物对系膜细胞增殖作用的研究

用［３Ｈ］胸腺嘧啶核甙（［３Ｈ－ｔｈｙｍｉｄｉｎｅ，［３Ｈ］－ＴｄＲ）掺入法测定花生四烯酸产物对体外培养的大鼠肾小球系膜细胞的增殖作用。前列腺素Ｅ２（ｐｒｏｓｔａｇｌａｎｄｉｎ，ＰＧ）抑制血清所致的系膜细胞增殖。血栓素Ａ２（ｔｈｒｏｍｂｏｘａｎｅ，Ｔｘ）类似物Ｕ４６６１９、白三烯（ｌｅｕｋｏｔｕｉｅｎｅ，ＬＴ）Ｃ４、ＬＴＤ、１２－羟二十碳四烯酸（１２－ｈｙｄｒｏｘｙｅｉｃｏｓａｔｅｔｒａｅｎｏｉｃａｃｉｄ，１２－ＨＥＴＥ）、１５－ＨＥＴＥ促进静息的系膜细胞增殖，ＬＴＢ４及５－ＨＥＴＥ无此作用。用特异性蛋白激酶Ｃ（ｐｒｏｔｅｉｎｋｉｎａｓｅＣ，ＰＫｃ）抑制剂可抑制Ｕ４６６１９、ＬＴＣ４、ＬＴＤ４及１２－ＨＥＴＥ的促增殖作用。ＰＧＦ２α、Ｕ４６６１９、ＬＴＣ４、ＬＴＤ４促进系膜细胞合成二脂酰甘油（ｄｉａｃｙｌｇｌｙｃｅｒｏｌ，ＤＡＧ）。ＰＧＦ２α及ＬＴＤ４刺激系膜细胞合成三磷酸肌醇（ｉｎｏｓｉｔｏｌｔｒｉｐｈｏｓｐｈａｔｅ，ＩＰ３）。提示部分花生四烯酸产物活化ＰＫＣ而促进系膜细胞增殖。     

The analgesic effect of crotoxin on neuropathic pain is mediated by central muscarinic receptors and 5-lipoxygenase-derived mediators

Crotoxin (CTX), a neurotoxin isolated from the venom of the South American rattlesnake Crotalus durissus terrificus, induces analgesia. In this study, we evaluated the antinociceptive effect of CTX in a model of neuropathic pain induced by rat sciatic nerve transection. Hyperalgesia was detected 2 h after nerve transection and persisted for 64 days. Immersion of proximal and distal nerve stumps in CTX solution (0.01 mM for 10 s), immediately after nerve transection, blocked hyperalgesia. The antinociceptive effect of CTX was long-lasting, since it was detected 2 h after treatment and persisted for 64 days. CTX also delayed, but did not block, neurectomy-induced neuroma formation. The effect of CTX was blocked by zileuton (100 mg/kg, p.o.) and atropine (10 mg/kg, i.p.), and reduced by yohimbine (2 mg/kg, i.p.) and methysergide (5 mg/kg, i.p.). On the other hand, indomethacin (4 mg/kg, i.v.), naloxone (1 mg/kg, i.p.), and N-methyl atropine (30 mg/kg, i.p.) did not interfere with the effect of CTX. These results indicate that CTX induces a long-lasting antinociceptive effect in neuropathic pain, which is mediated by activation of central muscarinic receptors and partially, by activation of α-adrenoceptors and 5-HT receptors. Eicosanoids derived from the lipoxygenase pathway modulate the action of crotoxin.     

Altered hepatic eicosanoid concentrations in rats treated with the peroxisome proliferators ciprofibrate and perfluorodecanoic acid

 Several hypolipidemic drugs, plasticizers, and other chemicals induce hepatic peroxisome proliferation and hepatocellular carcinomas in rodents. These agents induce and promote hepatocarcinogenesis by unknown mechanisms, since most studies have not found them to be genotoxic. Peroxisome proliferators increase the expression of several genes, including those for the enzymes of the peroxisomal β-oxidation pathway and the cytochrome P-450 4A family, which metabolize lipids, including eicosanoids and their precursor fatty acids. The peroxisome proliferators ciprofibrate and perfluorodecanoic acid (PFDA) were therefore examined for their ability to alter hepatic eicosanoid concentrations. Rats received injections of 3 or 10 mg PFDA/kg body weight every 14 days or were fed 0.01% ciprofibrate for 10 days, 24 days, 6 weeks, 26 weeks, or 54 weeks. The activity of the peroxisomal enzyme fatty acyl CoA oxidase was significantly increased by both ciprofibrate and PFDA at all times. Hepatic concentrations of prostaglandins E₂ and F_2α (PGE₂, PGF_2α), thromboxane B₂ (TXB₂), and leukotriene C₄ (LTC₄) were measured by immunoassay. Concentrations of PGE₂, PGF_2α, and TXB₂ were decreased in livers of rats receiving ciprofibrate or PFDA compared to livers of control rats, with ciprofibrate exerting a greater effect than PFDA at the doses used. Hepatic LTC₄ concentrations were significantly increased by ciprofibrate at 10 days and PFDA at 54 weeks, and significantly decreased by PFDA at 26 weeks. These alterations in eicosanoid concentrations may be important in the natural history of peroxisome proliferator-induced hepatocarcinogenesis. Received: 15 September 1994/Accepted: 15 December 1994