Potent Protective Effect Of &#945 -Tocopherol And Fish Oil On In Vivo Paraquat Induced Oxidative Damage In Rats

The potential protective role of &#945-tocopherol and fish oil against oxidative damage induced by paraquat were investigated. Forty male albino rats with average body weight of 100-120 gm were housed in 8 groups of 5 rats each. The first group served as control and injected with saline, group 2 was injected with a single dose of paraquat (10 mg/kg, intraperittoneally) for 24 h prior to decapitation (P), group 3 was administered orally with vitamin E (100 mg/kg) five times a week (E), group 4 was administered orally with fish oil (20 mg/kg) five times a week (FO); group 5 received FO+E, groups 6, 7 and 8 were administrated with P+E, P+FO and P+E+FO respectively. The content of microsomal proteins, drug metabolizing enzymes and thiobarbituric acid reactive substances (TBARS) were determined in liver microsome after treatment. Vitamin E together with fish oil significantly decreased the content of cytochrome b5 (

5-HT receptors mediating contraction in the rat-tail artery

We studied the effects of 5-HT in resistance vessels. Compounds acting on 5-HT2A and 5-HT1B receptors were tested on rat-tail arterial rings in varying experimental conditions. We tested 5-HT from 50 nM to 100 microM: the pD2 was 6.4 +/- 0.1. We evaluated vasoconstriction by 5-HT in tissues slightly depolarized with 30 mM KCl. In this condition, the 5-HT concentration-related contraction started at lower concentration in comparison to control tissues. Preincubation with 50 nM ketanserin, a 5-HT2A-antagonist, and 1 microM prazosin, an alpha1-antagonist, strongly inhibited concentration-related contraction by 5-HT: the pD2 was 3.2 +/- 0.2. Moreover, we experimented alpha-methyl-5-HT (alpha-me-5-HT) and 5-carboxamidotryptamine (5-CT), selective agonists at 5-HT2A and 5-HT1B receptors, respectively. Both agonists induced concentration-related contraction; the potency order observed was 5-HT > alpha-me-5-HT > 5-CT. Finally, we studied SB 224289, a selective 5-HT1B-antagonist, on contraction by 5-HT in control and in depolarized conditions. 0.2 microM SB 224289 significantly inhibited vasoconstriction induced by 5-HT in depolarized vascular tissues. The data indicate that vasoconstriction induced by 5-HT is mainly dependent on 5-HT2A receptors; however, 5-HT1B receptors are also present in rat-tail artery

5-HT receptors mediating contraction in the rat-tail artery

none45-HT receptors mediating contraction in the rat-tail artery. Studies on the regulation of vasoconstriction by 5-hydroxytryptamine.noneNICOLETTI P.; RAGAZZI E.; CAPARROTTA L.; FROLDI G.Nicoletti, P.; Ragazzi, Eugenio; Caparrotta, Laura; Froldi, Guglielmin