[Effect of nucleus paragigantocellularis destruction on Caffeine and Naloxone withdrawal sings precipitations in male rats]

It is showed that the activity of paragiganocellularis [PGi] nucleus is diminished in addict animals, but in contrast this activity was augmented during withdrawal period. Also, regarding interrelation of opiate and adenosine systems, it was obvious that in each system not only the specific antagonists but also the contrast antagonists system could produce withdrawal signs. In this study the role of PGi nucleus in precipitation of withdrawal signs induced by opiate and adenosine antagonists was investigated. In this experimental study, dependency was induced by escalating doses of morphine via drinking water which were prescribed to the animals during a 21 days period. Then addicated rate were subjected to four groups: 1-Intact 2-Sham 3-unilateral PGi destruction and 4-bilateral PGi destruction. Withdrawal signs were induced by 1-Naloxone [2 mg/kg sc.] and 2-Caffeine [50 mg/Kg ip.] administration in each group. Data was gathered and then analyzed using one way ANOVA, Tukey and Chi square tests. P< 0.05 was considered significant. Naloxone withdrawal signs were consisted of diarrhea, ejaculation, teeth chattering, ptosis, irritability, wet dog shake, strop tail, jumping and weight loss. Following bilateral PGi destruction there was a marked attenuation in three signs of irritability, teeth chattering and jumping sings. The number of withdrawal signs which were produced by Caffeine administration were less than Naloxone [diarrhea, ejaculation, teeth chattering, chewing, irritability and jumping]. However, destruction of PGi nucleus [bilateral] diminished four sgins including: diarrhea, ejaculation teeth chattering, and irritability. The present study showed that the withdrawal signs precipitated with Caffeine are less different than Naloxone, and the bilateral PGi destruction could markedly attenuate these sings in Caffeine group more than Naloxone ones

Evaluation of the HI-6 ability on reversal or prevention of paraoxon-induced changes in the function of Chichen Biventer cervices nerve-muscle preparation

Paralysis of skeletal muscles,which can lead to paralysis of respiratory muscles and death, is one of the most toxic effects of organophosphates [Ops],and oximes are almost the only known antidotes that can reverse or prevent such toxic effects. In the present research work, possible reversal or preventive effect of different concentrations of the relatively new oxime [HI-6] on paraoxon-induced changes on function of skeletal muscle of chicken biventer cervices [CBC] nerve- muscle preparation were studied using twitch tension recording technique. This is experimental study. For this purpose,twitches of the CBC muscle were evoked by stimulating the motor nerve at 0.1 Hz with pulses of 0.2 msec duration and a voltage of greater than that required to produce the maximum response. Twitches were recorded isotonically using Narco Biosystem. Our prior findings revealed that paraoxon at a concentration of 0.1 micro M induces a significant increase [more than 100%] in the twitch amplitude, and therefore, this concentration was used to examine the efficacy of HI-6 to reverse or prevent such effects. HI-6 at 1000 micro M could almost fully reverse [when it was used as post treatment] or prevent [when it was used as pretreatment or at the same time as toxin] the effect of paraoxon. It could also reverse or reduce this effect to about 25%, 50% and 75% at 300,100 and 30 micro M, respectively. Furthermore, HI-6 at 10 micro M produced no significant preventive or reversal effect. However, HI-6 alone at 1000 micro M increased the twitch amplitude by about 20%.These data indicated that HI-6 could be recognized as an antidote of paraoxon, although it may have other effects at high concentrations

[Evaluation of the HI-6 abillity on reversal or prevention of paraoxon-induced changes in the function of Chichen Biventer cervices nerve-muscle preparation]

Background: Paralaysis of skeletal muscles, which can lead to paralysis of respiratory muscles and death, is one of the most toxic effects of organophosphates [Ops], and oximes are almost the only known antidotes that can reverse or prevent such toxic effects. In the present research work, possible reversal or preventive effect of different concentrations of the relatively new oxime [Hl-6] on paraoxon-induced changes on function of skeletal muscle of chicken biventer cervices [CBC] nerve- muscle preparation were studied using twitch tension recording technique

Materials and methods: This is experimental study. For this purpose, twiches of the CBC muscle were evoked by stimulating the motor nerve at 0.1 Hz with pulses of 0.2 msec duration and a voltage of greater than that required to produce the maximum response. Twitches were recorded isotonically using Narco Biosystem

Results: Our prior findings revealed that paraoxon at a concentration of 0.1 micro M induces a significant increase [more than 100%] in the twitch amplitude, and therefore, this concentration was used to examine the efficacy of Hl-6 to reverse or prevent such effects. Hl-6 at 1000 micro M could almost fully reverse [when it was used as post treatment] or prevent [when it was used as pretreatment or at the same time as toxin] the effect of paraoxon. It could also reverse or reduce this effect to about 25%, 50% and 75% at 300,100 and 30 micro M, respectively. Furthermore, Hl-6 at 10 micro M produced no significant preventive or reversal effect. However, Hl-6 alone at 1000 micro M increased the twitch amplitude by about 20%

Conclusions: These data indicated that Hl-6 could be recognized as an antidote of paraoxon, although it may have other effects at high concentrations