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Acute administration of cyclo (His-Pro) to rats cause a dose-dependent decrease in ethanol-induced hypothermia. Bromination of the imidazole moiety of histidine in cyclo (His-Pro) resulted in a significant increase in its potency to attenuate ethanol hypothermia. In contrast, benzylation of the imidazole moiety of histidine or the substitution of one or both of the amino acids in cyclo(His-Pro) led to a total loss of its thermomodulatory activity. In conclusion, it appears from these preliminary data that it may be possible to design analogs of CHP that may be effective antagonists for ethanol hypothermia.

Acute administration of cyclo (His-Pro) to rats cause a dose-dependent decrease in ethanol-induced hypothermia. Bromination of the imidazole moiety of histidine in cyclo (His-Pro) resulted in a significant increase in its potency to attenuate ethanol hypothermia. In contrast, benzylation of the imidazole moiety of histidine or the substitution of one or both of the amino acids in cyclo(His-Pro) led to a total loss of its thermomodulatory activity. In conclusion, it appears from these preliminary data that it may be possible to design analogs of CHP that may be effective antagonists for ethanol hypothermia.

An investigation on the mechanism of neurochemical changes in physically or psychologically stressed mice was carried out. Physical stress was induced by electric foot shocks (2 mA for 5 s at 30-s intervals), and psychological stress was induced by emotional stimuli from electric foot-shocked mice using a communication box. The serum and brain calcium levels and immunohistochemical brain dopamine levels increased, and the ethanol-induced sleeping time was prolonged following exposure to these stimuli. The effects of electric foot shocks on these physiological parameters were greater than those of emotional stimuli. In the psychologically stressed mice, serum and brain calcium levels significantly increased 15 and 60 min, respectively, after the start of exposure to stimuli. Also, the immunohistochemical dopamine levels in the neostriatum and nucleus accumbens regions after 60 min of exposure to psychological stress were higher by 23% (P < 0.01) and 27% (P < 0.01), respectively, than those in unstressed control mice. Moreover, the ethanol-induced sleeping time was prolonged by approximately 60-100% (P < 0.01) in mice exposed to psychological stress for 30-120 min. The effect of emotional stimuli to prolong the ethanol-induced sleeping time was inhibited by intracerebroventricular administration of W-7 (a calmodulin antagonist) or alpha-methyltyrosine (an inhibitor of tyrosine hydroxylase). In light of previous reports that calcium activates dopamine synthesis in the brain via a calmodulin-dependent system, it is suggested that physical or psychological stimuli induce an increase in the brain calcium level, and this increased calcium level in turn enhances dopamine synthesis in the brain. Subsequently, an increased dopamine level induces various physiological changes related to stress-dependent phenomena.

An investigation on the mechanism of neurochemical changes in physically or psychologically stressed mice was carried out. Physical stress was induced by electric foot shocks (2 mA for 5 s at 30-s intervals), and psychological stress was induced by emotional stimuli from electric foot-shocked mice using a communication box. The serum and brain calcium levels and immunohistochemical brain dopamine levels increased, and the ethanol-induced sleeping time was prolonged following exposure to these stimuli. The effects of electric foot shocks on these physiological parameters were greater than those of emotional stimuli. In the psychologically stressed mice, serum and brain calcium levels significantly increased 15 and 60 min, respectively, after the start of exposure to stimuli. Also, the immunohistochemical dopamine levels in the neostriatum and nucleus accumbens regions after 60 min of exposure to psychological stress were higher by 23% (P < 0.01) and 27% (P < 0.01), respectively, than those in unstressed control mice. Moreover, the ethanol-induced sleeping time was prolonged by approximately 60-100% (P < 0.01) in mice exposed to psychological stress for 30-120 min. The effect of emotional stimuli to prolong the ethanol-induced sleeping time was inhibited by intracerebroventricular administration of W-7 (a calmodulin antagonist) or alpha-methyltyrosine (an inhibitor of tyrosine hydroxylase). In light of previous reports that calcium activates dopamine synthesis in the brain via a calmodulin-dependent system, it is suggested that physical or psychological stimuli induce an increase in the brain calcium level, and this increased calcium level in turn enhances dopamine synthesis in the brain. Subsequently, an increased dopamine level induces various physiological changes related to stress-dependent phenomena.

Our previous work indicated a role for fyn-kinase in mediating several ethanol- and GABA(A) agonist-mediated behaviors. In the present work we investigate behavioral sensitivity to ethanol and several GABA(A) compounds in mice that over-express fyn-kinase in forebrain to further characterize the role of this non-receptor tyrosine kinase in the mediation of ethanol sensitivity. Transgenic mice over-expressing fyn-kinase were tested for sensitivity to ethanol-induced loss of righting reflex and ethanol preference drinking using a two-bottle choice drinking paradigm. Loss of righting reflex induced by 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol (THIP; GABA(A) agonist) and etomidate (GABA(A) positive allosteric modulator) were also assessed. Fyn over-expressing mice exhibited shorter durations of ethanol-induced loss of righting reflex in the absence of differences in the rate of blood ethanol clearance, and exhibited reduced ethanol preference drinking. The genotypes did not differ in initial sensitivity to ethanol-induced loss of righting reflex suggesting development of greater acute tolerance to this ethanol action. Fyn over-expressing and wild-type mice also did not differ in sensitivity to loss of righting reflex induced by THIP and etomidate. The present results suggest regional specificity for fyn-kinase in the modulation of ethanol and GABAergic behavioral sensitivity. Fyn-kinase over-expression in forebrain structures modulates ethanol's hypnotic actions, as well as ethanol preference and consumption. Moreover, fyn over-expression in forebrain does not alter hypnotic sensitivity to THIP or etomidate, supporting data from fyn null mutant mice suggesting that cerebellar structures mediate the hypnotic actions of these GABAergic compounds.

Our previous work indicated a role for fyn-kinase in mediating several ethanol- and GABA(A) agonist-mediated behaviors. In the present work we investigate behavioral sensitivity to ethanol and several GABA(A) compounds in mice that over-express fyn-kinase in forebrain to further characterize the role of this non-receptor tyrosine kinase in the mediation of ethanol sensitivity. Transgenic mice over-expressing fyn-kinase were tested for sensitivity to ethanol-induced loss of righting reflex and ethanol preference drinking using a two-bottle choice drinking paradigm. Loss of righting reflex induced by 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol (THIP; GABA(A) agonist) and etomidate (GABA(A) positive allosteric modulator) were also assessed. Fyn over-expressing mice exhibited shorter durations of ethanol-induced loss of righting reflex in the absence of differences in the rate of blood ethanol clearance, and exhibited reduced ethanol preference drinking. The genotypes did not differ in initial sensitivity to ethanol-induced loss of righting reflex suggesting development of greater acute tolerance to this ethanol action. Fyn over-expressing and wild-type mice also did not differ in sensitivity to loss of righting reflex induced by THIP and etomidate. The present results suggest regional specificity for fyn-kinase in the modulation of ethanol and GABAergic behavioral sensitivity. Fyn-kinase over-expression in forebrain structures modulates ethanol's hypnotic actions, as well as ethanol preference and consumption. Moreover, fyn over-expression in forebrain does not alter hypnotic sensitivity to THIP or etomidate, supporting data from fyn null mutant mice suggesting that cerebellar structures mediate the hypnotic actions of these GABAergic compounds.

Involvement of N-methyl-D-aspartate (NMDA) receptor complex and 5-hydroxytryptamine3 (5-HT3) receptors in state-dependent learning (SDL) induced by ethanol (EtOH) was investigated in the step-through passive avoidance task in rats. Pre-training injections of EtOH or MK-801 reduced step-through latency in the test session conducted 24 h after the training session. Pre-test as well as pre-training injections of EtOH failed to reduce the latency, while pre-training and pre-test injections of MK-801 reduced the latency. These results show that EtOH but not MK-801 produces SDL. SDL induced by EtOH was blocked by ICS205-930 injected before either the training or test session. However, ICS205-930 failed to block SDL induced by diazepam and muscimol. These results suggest that NMDA receptor complex may not be involved in SDL, and that 5-HT3 receptors may contribute to SDL induced by EtOH but not by diazepam and muscimol.

Involvement of N-methyl-D-aspartate (NMDA) receptor complex and 5-hydroxytryptamine3 (5-HT3) receptors in state-dependent learning (SDL) induced by ethanol (EtOH) was investigated in the step-through passive avoidance task in rats. Pre-training injections of EtOH or MK-801 reduced step-through latency in the test session conducted 24 h after the training session. Pre-test as well as pre-training injections of EtOH failed to reduce the latency, while pre-training and pre-test injections of MK-801 reduced the latency. These results show that EtOH but not MK-801 produces SDL. SDL induced by EtOH was blocked by ICS205-930 injected before either the training or test session. However, ICS205-930 failed to block SDL induced by diazepam and muscimol. These results suggest that NMDA receptor complex may not be involved in SDL, and that 5-HT3 receptors may contribute to SDL induced by EtOH but not by diazepam and muscimol.

We performed compulsory superselective transcatheter arterial embolization on local hypovascular liver metastases under balloon occlusion using a 1-mm (3 F) coaxial microballoon catheter in 2 cases. One case was a metastasis from breast cancer (maximum diameter 5.5 cm) at segment 7. The other case comprised metastases from rectal cancer (maximum diameter 8 cm) at segments 7 and 8. Absolute ethanol (50%) mixed with Lipiodol (50%) was used for embolization. No major treatment-related complications occurred. No local recurrence was observed in either case in follow-up CT and MR studies of up to 16 and 9 months respectively. This technique may thus be applied as an alternative to surgical resection in the treatment of local hypovascular liver tumors.