Cholecystectomy with and without drainage

Thirty patients underwent cholecystectomy without drainage, and 16 matched controls cholecystectomy with drainage. The wound infection rate was lower, hospital stay shorter and overall complication rate less in undrained patients. This study suggests that surgical drainage after uncomplicated cholecystectomy is unnecessary and may be unwise.

Central adenosinergic system involvement in ethanol-induced motor incoordination in mice

To clarify if the behavioral interaction between ethanol and adenosine reported previously occur centrally or due to a peripheral hemodynamic change, the effect of i.c.v. adenosine agonists, N6-(R-phenylisopropyl)adenosine (R-PIA), N6-(S-phenylisopropyl)adenosine, 5'-(N-cyclopropyl)-carboxamidoadenosine, antagonists, theophylline and 8-p-(sulfophenyl)theophylline as well as enprofylline on ethanol-(i.p.)-induced motor incoordination was evaluated by rotorod. Adenosine agonists and antagonists dose dependently accentuated and attenuated, respectively, ethanol-induced motor incoordination, thereby suggesting a central mechanism of adenosine modulation of this effect of ethanol and confirmed our previous reports in which adenosine agonists and antagonists were given i.p. Enprofylline, a weak adenosine antagonist but potent inhibitor of cyclic AMP phosphodiesterase, did not alter ethanol's motor incoordination, further supporting involvement of brain adenosine receptor mechanism(s) in ethanol-adenosine interactions. Results from R-PIA and N6-(S-phenylisopropyl)adenosine experiments showed nearly a 40-fold greater potency of R-vs. S-diastereoisomer, suggesting predominance of adenosine A1 subtype. However, 5'-(N-cyclopropyl)-carboxamidoadenosine data indicate complexity of the mechanism(s) and point toward an additional involvement of a yet unknown subtype of adenosine A2. No effect of ethanol on blood or brain levels of [3H]R-PIA was noted and sufficient amount of the latter entered the brain to suggest adenosine receptor activation adequate to produce behavioral interaction with ethanol. There was no escape of i.c.v.-administered [3H]R-PIA from brain to the peripheral circulation ruling out a peripheral and supporting a central mechanism of ethanol-adenosine interaction.(ABSTRACT TRUNCATED AT 250 WORDS)

Functional correlation between subclasses of brain adenosine receptor affinities and ethanol-induced motor incoordination in mice

To further investigate if the modulation of ethanol-induced motor incoordination is by brain adenosine A1 and/or A2 receptor, adenosine analogs with wide variability in their affinity for A1 and A2 subtypes were administered ICV and their effect on ethanol-induced (IP) motor incoordination was evaluated by rotorod. A dose-dependent marked accentuation of ethanol-induced motor incoordination by adenosine agonists (CHA, NECA, CPA, DCCA) tested, with nearly no effect on normal motor coordination in the absence of ethanol, was observed. There was a positive correlation between A2 affinity, A2/A1 affinity ratio but a negative correlation between A1 affinity and the potency (ED50) of adenosine agonists to accentuate ethanol-induced motor incoordination. However, with the high potency of CHA and NECA, both having significant affinity for A1 and A2 receptors, together with the well known membrane perturbation by ethanol, it seems difficult to rule out until more information becomes available the contribution of A1 receptor activation to adenosine modulation of ethanol-induced motor incoordination. The high density of high affinity A2 (A2a) in the striatum and of A1 in the cerebellum and several brain areas and the known importance of these two brain areas in the motor control, indirectly supports or at least provides a circumstantial evidence for a functional correlation between ethanol-induced motor incoordination and brain adenosine receptors.

Brain adenosine modulation of behavioral interactions between ethanol and carbamazepine in mice

The effect of the anticonvulsive drug carbamazepine on ethanol-induced motor incoordination and loss-of-righting reflex was investigated in male CD-1 mice. The results of the investigation showed that carbamazepine significantly potentiated the motor incoordinating effect of ethanol in a dose-dependent fashion. Although carbamazepine did not alter the onset time, it significantly prolonged the duration of ethanol-induced loss-of-righting reflex. Pretreatment with theophylline significantly attenuated the carbamazepine-induced potentiation of ethanol-induced motor incoordination and loss-of-righting reflex. Results from a blood ethanol study indicated no effect of carbamazepine on the clearance of ethanol. The data suggest the involvement of nonadenosinergic mechanism in carbamazepine-ethanol behavioral interactions which is responsible for the accentuating effects of carbamazepine on ethanol-induced motor incoordination and duration of loss-of-righting reflex.

Effect of acute ethanol on uptake of [3H]adenosine by rat cerebellar synaptosomes

Many classes of CNS-acting drugs have been suggested to act at least partially via inhibition of adenosine uptake. Synaptosomal uptake of [3H]adenosine and the effect of acute ethanol on it were studied in a rat brain area known to be involved in the coordination and modulation of normal motor activity, the cerebellum. Uptake of [3H]adenosine was found to be linear with time (about 40 sec) and increasing concentrations (up to 1.5 microM) of adenosine. The uptake of [3H]adenosine was inhibited by dilazep (IC50 = 2.5 x 10(-7) M) in a dose-dependent manner. Pharmacologically and/or toxicologically relevant concentrations of ethanol (2.5 to 100 mM) significantly inhibited the uptake of [3H]adenosine between 12 and 15%. Lineweaver-Burk plots indicated that both in vitro (25 mM) and in vivo (1.5 g/kg i.p.; 30 mM blood level) ethanol lowered Km as well as Vmax values for adenosine uptake to nearly the same extent. In the case of in vivo ethanol, no ethanol was present during the assay since synaptosome preparation would wash out residual ethanol. The results of the present study indicate possible membranal alterations by in vivo ethanol. It is concluded that the uptake of [3H]adenosine is inhibited by intoxicating concentrations of ethanol in vitro and by acute ethanol (1.5 g/kg) in vivo. This may partially explain the modulatory role of endogenous adenosine in ethanol-induced motor disturbances.

Effect of acute ethanol on release of endogenous adenosine from rat cerebellar synaptosomes

The effects of pharmacologically relevant concentrations of ethanol on the release of endogenous adenosine from rat cerebellar synaptosomes were investigated. Release was conducted for 5, 10, 30, or 60 s after which time the incubation medium (containing the released adenosine) was rapidly separated from the synaptosomal membranes by vacuum filtration. The adenosine content of the filtrate was measured by HPLC-fluorescence detection. Both basal and KCl-stimulated adenosine release consisted of an initial rapid phase, for the first 10 s, that was followed by a relatively slower phase. Basal endogenous adenosine release was estimated as 199 +/- 14 pmol/mg protein/5 s. Potassium (chloride) increased adenosine release from the basal level to 433 +/- 83 pmol/mg protein/5 s. Ethanol caused a dose-dependent increase of adenosine release. The interaction between dilazep and ethanol indicates that ethanol-stimulated release does not involve the dilazep-sensitive transport system. The results support previous findings that indicate that cerebellar adenosine is involved in the mediation of ethanol-induced motor disturbances in the rat.

Central nervous system effects and behavioral interactions with ethanol of centrally administered dilazep and its metabolites in mice

Dilazep (i.p.), a coronary vasodilator and an uptake inhibitor of adenosine, dose dependently potentiated acute ethanol-induced motor incoordination in mice. In view of peripheral cardiovascular depressive effects of dilazep, the effect of i.c.v. dilazep (25, 50 and 75 micrograms), and its metabolites, 1,4-bis(3-hydroxypropyl)perhydro-1,4-diazepine (BHPD) (15, 31 and 62 micrograms) and 1-[3-(3,4,5-trimethoxybenzoyloxy)propyl]perhydro-1,4-diazepine (TBPD) (62 and 125 micrograms) on ethanol-induced motor incoordination was studied. Dose-related potentiation of ethanol-induced motor incoordination was noted with dilazep and its metabolites. Whereas dilazep (i.p.) produced no apparent central nervous system (CNS) effects, by i.c.v. route, it caused CNS excitation including tonic-clonic seizures. Adenosine uptake inhibition, Ca2+ entry blockade or direct activation of adenosine receptors was ruled out as the possible mechanism of seizures because dipyridamole, verapamil or N6-(2-phenylisopropyl)-adenosine (R-PIA) administered i.c.v., while potentiating ethanol (i.p.)-induced motor incoordination did not produce seizures. The CNS excitation was minimal with BHPD and none with TBPD. Theophylline pretreatment partially blocked potentiation of ethanol-induced motor incoordination by dilazep and BHPD and not by TBPD. The data suggest dilazep-induced potentiation of ethanol-induced motor incoordination is partially due to central adenosine receptor mechanism and partly due to other yet unknown mechanism(s) and further supported our earlier reports about adenosine involvement in the CNS effects of ethanol. The data also suggest that dilazep (i.c.v.)-induced seizures are due to mechanism(s) other than adenosine uptake inhibition, Ca2+ entry blockade or direct adenosine receptor activation.

Release of endogenous glutamate from rat cerebellar synaptosomes: interactions with adenosine and ethanol

The effects of ethanol and adenosine receptor agonist R-PIA and antagonist theophylline on release of endogenous glutamate were tested in rat cerebellar synaptosomal preparation. Release was carried out for 5 to 60 sec after which time the released glutamate was separated from the synaptosomal membranes by rapid filtration. The amount of released glutamate in the filtrate was measured by an enzyme-linked fluorometric assay. Basal endogenous glutamate release was estimated as 3.7 +/- 0.3 nmol/mg protein/5 sec and was stimulated by high K+. Glutamate release consisted of an initial rapid phase for the first 10 sec that was followed by a relatively slower phase. Both Ca2+-dependent and Ca2+-independent glutamate release were observed which suggested the involvement of both neuronal and glial constituents of the synaptosomal preparation, respectively. Pharmacologically relevant concentrations of ethanol (25-100 mM) caused a trend toward a dose-dependent inhibition of glutamate release. R-PIA and theophylline inhibited and stimulated, respectively, basal release of glutamate and R-PIA-inhibited release was blocked by theophylline. Ethanol (25 mM) blocked the stimulatory effect of theophylline and the results of experiments following the inclusion of adenosine deaminase suggested the involvement of adenosine in this effect of ethanol. The results support our previous findings that suggest an involvement of cerebellar adenosine in the motor disturbing effects of acute ethanol and extend those findings by indicating that ethanol inhibits glutamate release from granule cells of the cerebellar cortex through an adenosine-sensitive mechanism.

The effects of various methods of sacrifice and of ethanol on adenosine levels in selected areas of rat brain

The effect of acute ethanol on adenosine content in four motor areas of the male Sprague-Dawley rat brain was investigated using HPLC-fluorescence detection. Since basal adenosine levels are difficult to assess due to extremely rapid turnover of adenosine, four different methods of sacrifice were also evaluated for adenosine measurement. The rank order for best results in measuring adenosine content with the various methods of sacrifice was: focused microwave irradiation greater than decapitation into liquid nitrogen greater than immersion into liquid nitrogen greater than decapitation. These differences probably reflect differences in degree of hypoxia and postmortem anoxia, factors well known to elevate adenosine, associated with the sacrifice method. Focused microwave irradiation of appropriate duration was found to be the best method of sacrifice and the results probably most closely reflect true basal adenosine levels. No significant alteration in adenosine content in any brain region examined was observed due to ethanol administration.

The biphasic effects of centrally and peripherally administered caffeine on ethanol-induced motor incoordination in mice

The possible biphasic effect of caffeine on acute ethanol-induced motor incoordination by rotorod evaluation was investigated in mice. Caffeine in various doses was administered intracerebroventricularly (i.c.v.) to mice implanted with permanent indwelling stainless steel guide cannulae and intraperitoneally (i.p.) to non-cannulated animals. A motor incoordinating test dose of ethanol, 2 g kg-1, was given i.p. in both cases. Caffeine less than 25 micrograms administered i.c.v., dose-dependently attenuated while 75 micrograms i.c.v. potentiated ethanol (i.p.)-induced motor incoordination. Similarly, caffeine less than 20 mg kg-1 given i.p., dose-dependently attenuated while 62.5 mg kg-1 potentiated ethanol (i.p.)-induced motor incoordination. The data obtained demonstrated that caffeine given either i.c.v. or i.p. exerted biphasic effects on ethanol-induced motor incoordination. The data also suggested that caffeine antagonized ethanol-induced motor micrograms i.c.v.; less than 20 mg kg-1 i.p.) caffeine is well known to display high affinity for adenosine binding sites. Therefore, the present investigation lends further support to our earlier suggestion that adenosine may be involved in the motor impairing effect of ethanol.

Mediation of acute ethanol-induced motor disturbances by cerebellar adenosine in rats

The possible involvement of brain adenosine in acute ethanol-induced motor incoordination (MI) and inhibition of spontaneous motor activity (SMA) was investigated in male Sprague-Dawley rats. Pretreatment with theophylline or 7-(2-chloroethyl)-theophylline, adenosine antagonists, markedly reduced ethanol-induced MI and inhibition of SMA during a 60 min test period compared with saline + ethanol group. On the contrary, pretreatment with (-)-N6(R-phenylisopropyl)adenosine (R-PIA), an adenosine agonist, or dilazep, an adenosine uptake blocker, markedly potentiated the ethanol-induced MI as well as inhibition of SMA in a 60 min test period compared with saline + ethanol group. No effect on motor coordination was seen when the drug pretreatment was not followed by ethanol. However, the adenosine agonists and antagonists did alter SMA when the pretreatment with these drugs was not followed by ethanol. Ethanol clearance was not altered by the drug pretreatment as blood ethanol levels were similar in all groups except for lower ethanol levels in the R-PIA-treated group. Adenosine A1 binding studies, using 3H-R-PIA as the radioligand and crude membrane preparation from cerebellar cortex, revealed an increase in Bmax with no significant change in Kd in ethanol-treated animals vs. saline control. Theophylline pretreatment prevented the increase in Bmax elicited by ethanol. Collectively, the data suggest that endogenous cerebellar adenosine may be a participating factor in ethanol-induced motor dysfunctions.

Behavioral interactions of ethanol and methylxanthines

The effect of the methylxanthines caffeine, theophylline and isobutylmethylxanthine (IBMX) on ethanol-induced ataxia and loss of righting reflex was investigated in three strains of mice. A significant potentiation of ethanol-induced ataxia was produced in all strains of mice at 20, 45 and 75 min after ethanol in mice pretreated with 62.5 mg/kg caffeine and 12.5 mg/kg IBMX. In mice pretreated with 40 mg/kg caffeine potentiation of ethanol-induced ataxia was observed only at 20 min after ethanol. Theophylline pretreatment produced no alteration in ethanol-induced ataxia. The results of methylxanthine pretreatment on ethanol-induced ataxia were similar, regardless of a shorter (10 min) or longer (75 min) pretreatment time. The methylxanthines produced no effect on motor coordination or behavior when administered separately. Although ethanol-induced loss of righting reflex was shortened by theophylline, neither caffeine nor IBMX altered the duration of loss of righting reflex. It is possible that inhibition of adenosine uptake, a known effect of the methylxanthines, may be a more likely explanation for the modulation of the behavioral effects of ethanol.

Effect of chronically administered methylxanthines on ethanol-induced motor incoordination in mice

The effect of chronic (10 days) administration of methylxanthines, caffeine, IBMX and theophylline on acute ethanol-induced motor incoordination has been investigated in the mice. In animals that received caffeine, 45 and 90 mg/kg/24 h, ethanol, 1.5 g/kg, produced motor incoordination significantly greater compared to that in the control groups. Significantly greater ethanol-induced motor incoordination was seen in animals fed IBMX, 30 and 60 mg/kg/24 h, compared to controls. Ethanol-induced increased motor incoordination in caffeine and IBMX-fed animals was also associated with significantly greater 3H-R-PIA binding in whole brains compared to tap water controls indicating an increase in brain adenosine binding sites. However neither motor incoordination nor 3H-R-PIA binding was altered in theophylline 75 and 150 mg/kg/24 h, fed animals. The increased motor incoordination associated with increased adenosine binding sites in the brains of caffeine and IBMX-fed animals suggests an involvement of central adenosine mechanisms in the motor incoordinating effect of ethanol and further supports our earlier suggestion for the role of adenosine in some of the central effects of ethanol.

Estrogen modulation of uterine adrenergic-cholinergic interaction: effects on vasoactivity and adrenergic receptors in the guinea pig

The regulation of uterine blood flow (UBF) in the guinea pig was investigated by determining the effects of steroid-catecholamine interaction on guinea pig UBF in cyclic (Day 0 = estrus) and ovariectomized (OVX)-steroid treated females. In cyclic guinea pigs, parallel elevations in uterine weight, UBF, beta and alpha receptor levels were observed during the estrus period, whereas uterine norepinephrine (NE) levels were low. In contrast, all parameters remained at low levels except NE levels during the luteal phase of the cycle which remained elevated in both normal and OVX-oil treated animals. Estrogen (E1)-treated females showed elevated uterine weights, UBF, beta, and alpha receptor levels but low uterine NE concentrations. Combined progesterone-estrogen (P2E1) treatment caused similar changes but maintained tissue NE at control levels. In the exposed uterine artery preparation, the sequential administration of acetylcholine followed by NE application induced a marked elevation in UBF in OVX, E-1-treated animals which was blocked by phentolamine (10(-6) M). This phenomena could not be demonstrated in either oil- or progesterone-treated OVX guinea pigs. In uterine membrane preparations from ovariectomized guinea pigs pretreated with either oil or progesterone, methacholine (cholinergic agonist; 10(-6) M) failed to alter the affinity of the alpha receptor for NE. However, in uterine preparations from OVX, estradiol-treated guinea pigs, methacholine significantly (P less than .05) increased the affinity of the alpha receptor for NE.(ABSTRACT TRUNCATED AT 250 WORDS)

Protective effect of zinc against ethanol toxicity in mice

Protection against the lethal effects of ethanol at 4.5 g/kg administered acutely was maximal when zinc was administered 60 min prior to ethanol. The timing of ethanol administration corresponded with elevated plasma levels of absorbed zinc. Protection was inversely related to the dose of zinc employed, as 0.5 mumol provided greater protection than 1.0 mumol, which provided greater protection than 2.0 mumol. Protection against ethanol lethality was greater if zinc was administered 60 min prior to each injection of ethanol. Acute zinc pretreatment did not alter the activity of liver alcohol dehydrogenase (ADH), nor did it alter the blood clearance of ethanol. Chronic zinc administration as ZnCl2, 100 micrograms/ml in the drinking water for 30 d, produced a 25% decrease in hepatic ADH activity, which was accompanied by a similar decrease in the intravascular clearance of ethanol.

In vivo mammalian metabolism of methylamine and methylurea and their metabolic interrelationship

The metabolism of methylamine has been investigated in the rabbit and rat, and evidence has been presented to show that the metabolism of the compound leads to the formation and excretion of methylurea, a metabolite suspected, but never conclusively shown, to exist by previous investigators. Urinary methylurea, after the administration of methyl-14C-amine, was shown to have 14C activity at both the carbonyl and methyl portions (groups) of the molecule. 14C activity in the carbonyl group of methylurea was derived from the same metabolic CO2 pool that is used in the formation of urinary urea and respiratory carbon dioxide. Administration of methyl-14C-amine led to the formation of respiratory 14CO2, as noted by various investigators, and it was shown that during a 24-hr period the ratio of specific activity (urea/respiratory CO2) approached 1, in agreement with previous data reported by Mackenzie and du Vigneaud [J. Biol. Chem. 172, 353-354 (1948)]. In order to quantitatively investigate some aspects of metabolism of methylurea, a procedure was developed for the convenient synthesis of N-methyl-14C-carbonyl-urea. In a series of experiments, the urinary urea of the animals injected with N-methyl-14C-carbonyl-urea and N-methyl-14C-urea was examined for radioactivity. Only limited amounts of 14C activity were found in the carbonyl group of urea following administration of N-methyl-14C-urea. However, after the administration of N-methyl-14C-carbonyl-urea, urinary urea contained a 200-fold excess of 14C activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Decidua-associated changes in guinea pig uterine blood flow and volume: relation to uterine norepinephrine concentrations

Changes in uterine blood flow (UBF) and uterine blood volume (UBV) during decidual tissue (DT) formation in the guinea pig were assessed at 2, 6, and 10 days postuterine trauma (PT). Uterine weight increased steadily between days 2 and 10 PT in DT-bearing animals as compared with the constant uterine weights observed in controls. Both UBF and UBV levels were elevated between days 2 and 10 PT in DT-bearing animals as compared with controls with the vascular changes being histologically related to the progressive stromal differentiation. Uterine norepnephrine (NE) levels were significantly (P less than or equal to 0.05-0.01) depressed in the hyperemic, DT-bearing uteri as compared with controls. These results indicate that the uterine hyperemia associated with DT formation in the guinea pig involves a sustained increase in uterine vascular volume as well as vascular perfusion rate under conditions of depressed uterine NE levels. These events are intimately associated with the support of stromal differentiation in the guinea pig.

The enzymatic systems involved in the mammalian metabolism of methylamine

The metabolism of methylamine has been investigated in the rat in order to elucidate the role of monoamine oxidase (MAO; EC 1.4.3.4) and intestinal bacteria in the metabolism of the compound. In a series of experiments in which short- and long-acting inhibitors of MAO were administered either alone or in combination prior to methyl-[14C]amine hydrochloride injection, the excretion of radioactivity in the expired air and the urine was examined to indirectly assess the role of MAO in the metabolism of methylamine. The data presented provide indirect evidence to demonstrate that the effect of iproniazid, an inhibitor of methylamine oxidation, is mediated through enzyme systems separate from MAO systems which have been invoked as major contributors to metabolism of methylamine by other investigators. The bacterial oxidation of methylamine in the intestine plays a minor role in the overall metabolism of the compound.

Effect of chronic ethanol administration on arterial baroreceptor function and pressor and depressor responsiveness in rats

The effect of chronic ethanol administration on arterial baroreflexes was investigated in rats. Comparison of the results with those obtained from rats kept on an isocaloric control diet revealed that chronic ethanol had a differential action on baroreflex sensitivity (BS). The BS after evoked graded rises in arterial pressure was inhibited significantly whereas that tested after an evoked fall in arterial pressure was augmented significantly in chronic ethanol rats. These changes in BS were not secondary to changes in blood pressure as resting arterial pressure was similar in both groups. However, the heart rate was slightly, but significantly lower in the ethanol group. Challenging isocaloric control and chronic ethanol rats with an acute dose of 0.5 g/kg of ethanol produced nonsignificant changes in BS when evoked changes in blood pressure were both pressor and depressor. A dose of 3 g/kg of ethanol decreased the BS tested after phenylephrine-evoked rises in pressure in both groups; however, the percentage of inhibition of BS was greater in the isocaloric control group. The pressor responsiveness to phenylephrine was reduced slightly in chronic ethanol-treated rats, in contrast to that evoked by angiotensin II which was augmented slightly as compared to the control group. There was no significant difference in the depressor responsiveness to nitroprusside. After injection of acute doses of 0.5 and 3 g/kg of ethanol, the dose-response curves to phenylephrine were shifted to the right in a dose-related fashion in both groups, whereas the angiotensin II and nitroprusside dose-response curve remained unchanged after 0.5 g/kg of ethanol in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

GABA mediation of the central effects of acute and chronic ethanol in mice

In acute ethanol studies aminooxyacetic acid (AOAA) alone produced marked hypothermia although a test dose of ethanol was able to produce a further drop in body temperature in AOAA treated mice. Even though tolerance to ethanol-induced hypothermia was present in ethanol-dependent mice, AOAA administration was able to produce a further decrease in body temperature. Bicuculline potentiated ethanol-induced hypothermia in the acute studies but the tolerance to hypothermia which had developed in ethanol-dependent mice prevented the bicuculline-induced potentiation of ethanol hypothermia. AOAA markedly potentiated acute ethanol-induced motor incoordination whereas bicuculline had no effect. Although partial tolerance had developed to ethanol-induced motor incoordination in dependent mice, AOAA potentiated, whereas a lower dose of bicuculline antagonized, motor incoordination. In the acute studies ethanol had a biphasic effect on AOAA-induced GABA accumulation in the hypothalamus and corpus striatum: low doses prevented and a slightly higher dose was without effect on GABA accumulation. Ethanol-dependent mice were unable to respond to an AOAA-induced increase in GABA accumulation although basal levels of GABA were unaffected by chronic ethanol ingestion. The results show that brain GABA or GABA-mediated central mechanisms may be involved in the mediation of ethanol-induced motor incoordination but not hypothermia.

Striatal and hypothalamic neurotransmitter changes during ethanol withdrawal in mice

The alterations in striatal and hypothalamic GABA, DA and its metabolites DOPAC and HVA, and in hypothalamic NE were investigated immediately after ethanol removal and during the withdrawal phase following 10 or 30 days of chronic ethanol administration. After 10 days of ethanol, GABA levels were increased immediately after ethanol removal in both the corpus striatum and the hypothalamus. The concentration of striatal DA was increased at days 2 and 3 of withdrawal and was unchanged at any other time. There was no change in the concentration of DOPAC and HVA in the hypothalamus at any time during withdrawal. Striatal DOPAC and HVA levels were increased only at day 7 of withdrawal after 10 and 30 days of ethanol feeding which was associated with a return of striatal DA to control levels. The concentration of NE in the hypothalamus was increased at days 1, 2 and 7 of withdrawal. After 30 days of ethanol, striatal GABA was increased only at day 7 of withdrawal whereas striatal DA levels were only increased at days 2 and 3 of withdrawal. Hypothalamic NE was markedly increased at days 2, 3 and 7 of withdrawal. The increase in DA concentration associated with no change in DOPA accumulation following inhibition of DOPA decarboxylase and a decrease in the striatal disappearance of DA after alphamethylparatyrosine (alpha-MT) suggests the presence of a hypodopaminergic state. On the other hand an increase in the disappearance of NE in the hypothalamus after alpha-MT suggests an increased NE turnover and a hyperadrenergic state during withdrawal. The increase in striatal GABA at day 7 of withdrawal after 30 days of ethanol may be a rebound phenomenon and may reflect the presence of a hypogabaergic state which has been shown to occur during ethanol withdrawal.

Regulation of estrogen-induced uterine hyperemia and contractility in the guinea pig: cholinergic modulation of an alpha-adrenergic response

The effects of estradiol (1 microgram: E-1) treatment on uterine hyperemia and uterine sensitivity to various biogenic compounds were evaluated in ovariectomized (OVX) animals treated with either sesame oil or E-1 for 3 days. The E-1 treatments induced significant elevations in uterine weight, blood flow, and alpha- and beta-receptor numbers as compared with oil-treated controls. In contrast, uterine norepinephrine (NE) levels were reduced in E-1-treated, OVX guinea pigs as compared with oil-treated controls. Uterine sensitivity and responsivity to NE (10(-6) M) and acetylcholine (ACH: 10(-8) M) were either comparable to, or enhanced, in E-1-treated animals as compared with controls. In particular, combined ACH-NE treatment induced a dramatic increase in contraction force in E-1-treated uteri as compared with uteri from oil-treated animals. The use of specific adrenergic alpha- (phentolamine: 10(-6) M) or beta- (propranolol: 10(-6) M) receptor blocking agents indicated that the estrogenic response was mediated via the alpha-adrenergic receptor complex. Since atropine (10(-8) M) effectively blocked the cholinergic accentuation of this uterine response, it is suggested that a cholinergic priming, or beta-receptor block, is necessary for the full expression of the alpha-adrenergic-mediated, estrogenic response in the guinea pig. The estrogen-associated increase in available alpha- and beta-receptors and depressed tissue NE levels probably account for both the hyperemic response and enhanced tissue sensitivity to biogenic compounds in the guinea pig.

Possible role of adenosine in the CNS effects of ethanol

The ability of adenosine to modify the CNS effects of acute and chronic ethanol was studied by using theophylline, an adenosine antagonist, and dipyridamole, a blocker of adenosine reuptake. We also studied the binding characteristics of adenosine using crude membranes of whole brain. Theophylline pretreatment prior to acute ethanol administration markedly reduced the duration of ethanol-induced sleep and similarly decreased the intensity and duration of motor incoordination. In chronic ethanol treated mice the effect of theophylline on ethanol-induced hypnosis and motor incoordination was similar to the acute experiment. Dipyridamole markedly prolonged the duration of ethanol-induced hypnosis and potentiated the motor incoordination produced by acute ethanol. However, in chronic ethanol treated mice dipyridamole was not able to potentiate the motor incoordinating effect of ethanol although it was able to prolong ethanol hypnosis similar to the results obtained in the acute ethanol study. Neither drug had any effect on ethanol-induced hypothermia, in either the acute or chronic studies. After 10 days of ethanol ingestion the adenosine dissociation constant was unchanged whereas the number of brain adenosine receptors was increased 28% although the increase did not reach statistical significance. The number of adenosine receptors was reduced 40% at 24 and 48 h after withdrawal and returned to prewithdrawal levels at 72 h. The dissociation constant was reduced at 24 and 48 h but by 72 h had returned to prewithdrawal levels. The marked changes in adenosine binding characteristics as well as the modification of some CNS effects of ethanol by drugs which influence either adenosine binding to its receptor or the availability of adenosine suggests that adenosine may be involved in the expression of some of the CNS effects of ethanol.

Ophthalmomyiasis caused by the sheep nasal bot, Oestrus ovis (Oestridae) larvae, in the Benghazi area of Eastern Libya

In a two-year study, from January 1977 to December 1978, 80 human cases of ophthalmomyiasis were recorded at the Benghazi Central Eye Clinic. Infections were due to larvae of the sheep nasal bot, Ostrus ovis. The annual incidence was estimated to be 10 per 100,000 population, with most of the cases occurring amongst males during the months of May, June and July. A typical case history is described to illustrate the clinical features and the treatment used.

The anticonvulsant and CNS activity of N-butyryl-N-butylurea in mice

As a further extension of our studies related to CNS activity of substituted butylureas, a number of derivatives of butylurea were synthesized. Among these a derivative of n-butylurea, N-butyryl-N-butylurea (NBNB) was prepared by acylation of n-butylurea with butyryl chloride in pyridine. The compound was found to possess considerable sedative-hypnotic action. Sleeping time of pentobarbital and barbital was significantly potentiated by NBNB. The compound also exhibited moderate anti-tremorine action and produced significant reduction in the activity ratio for Treadmill experiments. Significant anticonvulsive activity of NBNB was observed against strychnine, pentetrazole and supramaximal electroshock-induced convulsions. In addition to protection against tonic convulsions, the animals were also protected against strychnine and pentetrazole lethality.