Delta9-tetrahydrocannabinol stimulates palatable food intake in Lewis rats: effects of peripheral and central administration

To further study effects of delta9-tetrahydrocannabinol (THC) on food intake, male Lewis rats were maintained on rat chow and, on testing days, presented with chocolate cake batter (CCB) for 4h in addition to chow. Chow intake was not affected by THC administration in either experiment. In experiment 1 (n = 13) THC was administered intraperitoneally, and low doses produced increases in CCB intake for up to 1 h while the highest dose significantly decreased CCB intake over this same time period. In experiment 2 (n = 10) THC was injected intracerebroventricularly. Doses of 2.5, 10 and 25 microg significantly increased CCB intake for up to 1 h while stimulatory effects following 5 microg lasted up to 2h. Overall THC produced short-term increases in palatable food intake following both peripheral and central administration. Intraperitoneal administration resulted in an "inverted U" dose-response curve at all time points, while all central doses resulted in increased intake early in the time course and the hyperphagic effects were of greater duration than those following peripheral administration.

Delta(9)-THC stimulates food intake in Lewis rats: effects on chow, high-fat and sweet high-fat diets

Free-feeding adult male Lewis rats were administered intraperitoneal (i.p.) Delta(9)-tetrahydrocannabinol (THC) in doses of 0.5, 1.0 and 2.5 mg/kg, and effects on food intake were measured at 1, 2, 4, 6 and 24 h postinjection. Rats were fed rat chow, a high-fat diet (HF) or a high-fat sweetened (HFS) diet. Small increases in HF and HFS intake following doses of 0.5 or 1.0 mg/kg were seen at 1, 2 and 4 h, but not 6 or 24 h compared to vehicle intake. Increases following 0.5 and 1.0 mg/kg did not differ from each other at any time point and 2.5 mg/kg produced smaller differences at all time points. There was no difference between HF or HFS intake at any time point although larger increases were seen in the HF group compared to both chow and HFS following 0.5 and 1.0 mg/kg. This work confirms previous data in both humans and rats indicating a stimulatory role for cannabinoids in ingestive behavior.

[Multidisciplinary diagnostics in acute leukemia]

Establishing the exact diagnosis of patients suspected for acute leukemia is of paramount importance not only for instituting first-line treatment, but also for prognosticating the patient and determining the status of disease, e.g. in relation to minimal residual disease. In this overview the most recent developments regarding the methods for leukaemia diagnosis (cytology, histology, immunology, cytogenetics and molecular biology) are described and their respective merits and drawbacks are discussed. Special emphasis is given to the temporal relationship for application of the methods in the course of disease in these patients.

Temporal relationships between eating behavior and liver adenine nucleotides in rats treated with 2,5-AM

Administration of the fructose analog 2,5-anhydro-D-mannitol (2,5-AM) elicits eating behavior in rats by its action in the liver. To evaluate whether the decrease in liver ATP levels produced by injection of 2,5-AM plays a role in the eating response, we examined the relationship between changes in eating behavior and liver adenine nucleotide levels over time in rats given 2,5-AM. Liver ATP concentrations decreased within 15 min after injection of 2,5-AM (300 mg/kg ip), remained low for up to 90 min postinjection, and returned to control (saline injection) levels by 4 h after treatment. Rats fed ad libitum initiated eating between 15 and 45 min after 2,5-AM treatment, after liver ATP levels had declined. Rats given food 1 h after 2,5-AM treatment increased food intake, but if access to food was delayed for 4 h after 2,5-AM injection the eating response was attenuated or absent. Whereas liver AMP and ADP levels were also altered by injection of 2,5-AM, changes in food intake did not consistently track changes in these nucleotides. The results support the hypothesis that the eating response to 2,5-AM is triggered by a decrease in liver ATP level.

Alterations in deprivation, glucoprivic and sucrose intake following general, mu and kappa opioid antagonists in the hypothalamic paraventricular nucleus of rats

While opioid agonists administered into the hypothalamic paraventricular nucleus increase food intake in rats, naloxone reduces deprivation-induced intake. Ventricular administration of either mu (beta-funaltrexamine) or kappa (nor-binaltorphamine) opioid antagonists reduces spontaneous, deprivation, glucoprivic and palatable intake. The present study assessed whether microinjections of either general, mu or kappa opioid antagonists into the paraventricular nucleus altered either deprivation (24 h) intake, 2-deoxy-D-glucose hyperphagia or sucrose intake in rats. Deprivation intake was significantly reduced by nor-binaltorphamine (5 micrograms, 68 nmol, 30-33%), beta-funaltrexamine (5 micrograms, 100 nmol, 26-29%) or naltrexone (10 micrograms, 260 nmol, 26%) in the paraventricular nucleus. 2-Deoxy-D-glucose hyperphagia was significantly reduced only after 2 h by naltrexone (10 micrograms, 260 nmol, 69%), norbinaltorphamine (20 micrograms, 272 nmol, 69%) or beta-funaltrexamine (20 micrograms, 400 nmol, 83%) in the paraventricular nucleus. Sucrose intake was significantly reduced by nor-binaltorphamine (5 micrograms, 68 nmol, 27-36%), naltrexone (5-10 micrograms, 130-260 nmol, 18-31%) and beta-funaltrexamine (5 micrograms, 100 nmol, 20%) in the paraventricular nucleus. These data indicate that general, mu and kappa opioid antagonists administered into the hypothalamic paraventricular nucleus produce similar patterns of effects upon different forms of food intake as did ventricular administration, implicating this nucleus as part of the circuitry underlying opioid mediation of ingestion.

Modulation of morphine antinociception by the brain-penetrating H2 antagonist zolantidine: detailed characterization in five nociceptive test systems

Because histamine (HA) in the CNS may be a mediator of antinociception, a detailed investigation of the effects of the brain-penetrating H2 antagonist zolantidine (ZOL) was performed on five nociceptive tests in the presence and absence of morphine (MOR) in rats. ZOL inhibited MOR antinociception on the tail flick test, although a diurnal difference (inhibition in the dark cycle >> light cycle) was found. Similar results were found with the hot plate test, although details of the test procedure were significant. In contrast, ZOL induced opposing effects on MOR antinociception on two nonthermal tests (jump test and tail pinch test); ZOL alone induced moderate antinociception on the former test and mild antinociception on the latter test. Thus, ZOL exerts differential effects on baseline nociception and on MOR antinociception that vary depending on the nociceptive test employed, the light-dark cycle of the subjects, and the degree of stress associated with the nociceptive testing. These complex effects reveal the heterogeneous nature of opiate-induced modulation of nociception, and show that ZOL is a powerful tool for studying the relationships between opiates, HA, and nociceptive mechanisms.

Analysis of central opioid receptor subtype antagonism of hypotonic and hypertonic saline intake in water-deprived rats

Intake of either hypotonic or hypertonic saline solutions is modulated in part by the endogenous opioid system. Morphine and selective mu and delta opioid agonists increase saline intake, while general opioid antagonists reduce saline intake in rats. The present study evaluated whether intracerebroventricular administration of general (naltrexone) and selective mu (beta-funaltrexamine, 5-20 micrograms), mu, (naloxonazine, 50 micrograms), kappa (nor-binaltorphamine, 5-20 micrograms), delta (naltrindole, 20 micrograms), or delta 1 (DALCE, 40 micrograms) opioid receptor subtype antagonists altered water intake and either hypotonic (0.6%) or hypertonic (1.7%) saline intake in water-deprived (24 h) rats over a 3-h time course in a two-bottle choice test. Whereas peripheral naltrexone (0.5-2.5 mg/kg) significantly reduced water intake and hypertonic saline intake, central naltrexone (1-50 micrograms) significantly reduced water intake and hypotonic saline intake. Water intake was significantly reduced following mu and kappa receptor antagonism, but not following mu 1, delta, or delta 1 receptor antagonism. In contrast, neither hypotonic nor hypertonic saline intake was significantly altered by any selective antagonist. These data are discussed in terms of opioid receptor subtype control over saline intake relative to the animal's hydrational state and the roles of palatability and/or salt appetite.

Selective alterations in macronutrient intake of food-deprived or glucoprivic rats by centrally-administered opioid receptor subtype antagonists in rats

Two hypotheses have attempted to account for the abilities of opioid agonists and antagonists to respectively stimulate and inhibit food intake in rats. The first suggests that the opioid system selectively modulates fat intake, while the second suggest that the opioid system selectively alters intake of that macronutrient which the animal prefers. The present study evaluated these two hypotheses by examining total intake and individual macronutrient intake in either food-deprived (24 h) rats or rats made glucoprivic with 2-deoxy-D-glucose (2DG, 200 mg/kg, i.p.) following either vehicle treatment, systemic administration of naltrexone or intracerebroventricular administration of either naltrexone, the mu opioid antagonist, beta-funaltrexamine (B-FNA), the mu1 opioid antagonist, naloxonazine, the kappa opioid antagonist, nor-binaltorphamine (Nor-BNI), the delta opioid antagonist, naltrindole or the delta1 opioid antagonist, DALCE. Systemic administration of naltrexone (0.5-5 mg/kg significantly reduced carbohydrate, fat and total intake in deprived rats, and carbohydrate, fat, protein and total intake in glucoprivic rats. Central administration of naltrexone (5-50 micrograms) significantly reduced fat and total intake in both deprived and glucoprivic rats. B-FNA (5-20 micrograms) significantly reduced carbohydrate, fat and total intake in both deprived and glucoprivic rats Naloxonazine (10-100 micrograms) significantly reduced carbohydrate, fat and total intake in deprived rats, but failed to alter 2DC intake. Nor-BNI (5-20 micrograms) significantly reduced fat and total intake in glucoprivic rats, but failed to alter deprivation intake. Neither naltrindole (20 micrograms) nor DALCE (40 micrograms altered intake in deprived or glucoprivic rats. Carbohydrate or fat preference in deprived rats significantly increased the amount of explained variance in the inhibitory actions of central naltrexone, B-FNA and naloxonazine upon deprivation-induced intake. Carbohydrate or fat preference in glucoprivic rats significantly increased the amount of explained variance in the inhibitory action of systemic and central naltrexone, B-FNA, naloxonazine and Nor-BN upon 2-DG hyperphagia. These data are discussed in terms of the contentions that opioids either selectively alter fat intake pe se or selectively alter the preferred macronutrient.

Naltrexone, dopamine receptor agonists and antagonists, and food intake in rats: 2. 2-deoxy-D-glucose

Significantly greater inhibition of deprivation-induced food intake occurs following cotreatment with naltrexone and either the D1 antagonist, SCH-23390, the D2 agonist, quinpirole, or the D2 antagonist, haloperidol, relative to naltrexone alone. Cotreatment with the D1 agonist, SKF-38393, failed to alter naltrexone's inhibition of deprivation-induced intake. The present study evaluated whether each of these D1 and D2 agonists and antagonists altered hyperphagia following 2-deoxy-D-glucose (2DG) themselves or in combination with naltrexone. Neither SKF-38393 (1-10 mg/kg) nor SCH-23390 (25-200 micrograms/kg) altered 2DG hyperphagia. Quinpirole (0.025-0.5 mg/kg) dose dependently decreased 2DG hyperphagia. 2DG hyperphagia was respectively increased and decreased by low (50 micrograms/kg) and high (500 micrograms/kg) doses of haloperidol. Cotreatment of SKF-38393 (0.1-1 mg/kg) and naltrexone potently enhanced the inhibition of 2DG hyperphagia relative to naltrexone alone. In contrast, cotreatment of naltrexone and either SCH-23390 (100-200 micrograms/kg) or quinpirole (0.025-0.05 mg/kg) inhibited 2DG hyperphagia in a manner similar to that of naltrexone alone. Finally, cotreatment of haloperidol (5-50 micrograms/kg) and naltrexone transiently enhanced the inhibition of 2DG hyperphagia relative to naltrexone alone.

Naltrexone, dopamine receptor agonists and antagonists, and food intake in rats: 1. Food deprivation

Different forms of food intake are reduced by both agonists and antagonists of dopamine D1 and D2 receptors as well as general opioid antagonists. The present study evaluated whether deprivation (24 h)-induced food intake was altered following systemic administration of either the D1 agonist, SKF-38393, the D1 antagonist, SCH-23390, the D2 agonist, quinpirole, or the D2 antagonist, haloperidol, alone or in combination with the general opioid antagonist, naltrexone. Both SKF-38393 (5-10 mg/kg) and SCH-23390 (100-200 micrograms/kg) significantly and dose dependently reduced deprivation-induced intake. Whereas quinpirole (0.5-1 mg/kg) failed to alter deprivation-induced intake, haloperidol increased deprivation-induced intake at low (50 micrograms) doses and decreased intake at higher (100-500 micrograms/kg) doses. Naltrexone (2.5-10 mg/kg) significantly inhibited deprivation-induced intake. When naltrexone was paired with behaviorally ineffective doses of either SCH-23390 (2.5-100 micrograms/kg), quinpirole (0.01-1 mg/kg), or haloperidol (50 micrograms/kg), the degree of reduction of deprivation-induced intake was significantly greater than that produced by naltrexone alone. Pairing naltrexone with SKF-38393 produced reductions of deprivation-induced intake comparable to that of naltrexone alone.

Naltrexone, serotonin receptor subtype antagonists, and carbohydrate intake in rats

Functional interactions between serotonergic (5-HT) and opioid drugs have been observed with 5-HT3 receptor antagonism enhancing the inhibitory actions of naloxone and naltrexone in both food-deprived and glucoprivic rats; 5-HT2A/C receptor antagonism enhanced naltrexone's inhibition of insulin hyperphagia. The present study examined whether pretreatment with either general 5-HT (methysergide: 0.5-5 mg/kg), 5-HT2A/C (ritanserin: 0.25-2.5 mg/kg), or 5-HT3 (ICS 205930: 0.5-5 mg/kg) antagonists altered the pattern and magnitude of ad lib intake of simple (sucrose: 10%) or more complex (maltose dextrin: MD, 10%) carbohydrate solutions, or naltrexone's (0.25-2.5 mg/kg) inhibition of these forms of intake. Methysergide significantly increased the pattern and magnitude of sucrose intake at low (0.5-2.5 mg/kg) doses, and transiently delayed the pattern of MD intake at high (5 mg/kg) doses. Ritanserin significantly accelerated the pattern, but not the magnitude of sucrose intake at low (0.25-1.25 mg/kg) doses without affecting MD intake. ICS 205930 reduced the magnitude of sucrose intake at the highest (5 mg/kg) dose, and transiently reduced MD intake. Naltrexone dose dependently altered the pattern and magnitude of both sucrose and MD intake. Coadministration of ritanserin and naltrexone either eliminated or delayed the pattern of opioid antagonist inhibition of both sucrose and MD intake. Methysergide and ICS 205930 pretreatment produced minor changes in the pattern of naltrexone-induced inhibition. These data indicate that 5-HT receptor differentially modulate the pattern of carbohydrate intake, and indicate differential ingestive interactions between 5-HT and opioid antagonists under challenge and palatable conditions.

Differential modulation of angiotensin II and hypertonic saline-induced drinking by opioid receptor subtype antagonists in rats

Opioid modulation of ingestion includes general opioid antagonism of different forms of water intake, mu 2 receptor modulation of deprivation-induced water intake and delta 2 receptor modulation of saccharin intake. Water intake is stimulated by both central administration of angiotensin II (ANG II) and peripheral administration of a hypertonic saline solution; both responses are reduced by general opioid antagonists. The present study examined whether specific opioid receptor subtype antagonists would selectively alter each form of water intake in rats. Whereas systemic naltrexone (0.1-2.5 mg/kg, s.c.) reduced water intake induced by either peripheral ANGII (500 micrograms/kg, s.c.) or hypertonic saline (3 ml/kg, 10%), intracerebroventricular (i.c.v.) naltrexone (1-50 micrograms) only inhibited central ANGII (20 ng)-induced hyperdipsia. Both forms of drinking were significantly and dose-dependently inhibited by the selective kappa antagonist, nor-binaltorphamine (Nor-BNI, 1-20 micrograms). Whereas both forms of drinking were transiently reduced by the mu-selective antagonist, beta-funaltrexamine (beta-FNA, 1-20 micrograms), the mu 1 antagonist, naloxonazine (40 micrograms) stimulated drinking following hypertonic saline. The delta 1 antagonist, [D-Ala2, Leu5, Cys6]-enkephalin (DALCE, 1-40 micrograms) significantly reduced drinking following ANGII, but not following hypertonic saline; the delta antagonist, naltrindole failed to exert significant effects. These data indicate that whereas kappa opioid binding sites modulate hyperdipsia following hypertonic saline, mu 2, delta 1, and kappa opioid binding sites modulate hyperdipsia following ANGII. The mu 1 opioid binding site may normally act to inhibit drinking following saline.

Central opioid receptor subtype antagonists differentially reduce intake of saccharin and maltose dextrin solutions in rats

Opioid modulation of ingestion includes general opioid antagonism of deprivation-induced water intake and intake of sucrose and saccharin solutions. Previous studies using selective subtype antagonists indicated that opioid effects upon deprivation-induced water intake occurred through the mu2 receptor and that opioid effects upon sucrose intake occurred through kappa and mu2 receptors. The present study compared the effects of intracerebroventricular administration of opioid receptor subtype antagonists upon intakes of a saccharin solution and a maltose dextrin (MD) solution to determine which receptor subtypes were involved in modulation of ingestion of different preferred tastants. Significant reductions in saccharin intake (1 h) occurred following naltrexone (20-50 micrograms: 66%) and naltrindole (delta, 20 micrograms: 75%), whereas [D-Ala2, Leu5, Cys6]-enkephalin (DALCE, delta 1, 40 micrograms: 45%) had transient (5 min) effects. Neither beta-funaltrexamine (B-FNA, mu), naloxonazine (mu1), nor nor-binaltorphamine (Nor-BNI, kappa) significantly altered saccharin intake. Significant reductions in MD intake (1 h) occurred following naltrexone (5-50 micrograms: 69%) and B-FNA (1-20 micrograms: 38%). MD intake was not reduced by naltrindole, DALCE, naloxonazine and Nor-BNI. Peak antagonist effects were delayed (20-25 min) to reflect interference with the maintenance, rather than the initiation of saccharin or MD intake. Comparisons of opioid antagonist effects across intake situations revealed that naltrexone had consistently low ID40 values for saccharin (29 nmol), MD (25 nmol), sucrose (6 nmol) and deprivation (38 nmol) intake. Despite its significant effects relative to naloxonazine, B-FNA had significantly higher ID40 values for saccharin (800 nmol), MD (763 nmol) and sucrose (508 nmol) relative to deprivation (99 nmol) intake, suggesting that mu2 receptors may be mediating maintenance of intake rather than taste effects. Nor-BNI had low ID40 values for intake of sucrose (4 nmol), but not for saccharin (168 nmol), MD (153 nmol) and deprivation (176 nmol), suggesting that kappa receptors may mediate ingestion of sweet-tasting stimuli. That delta (naltrindole: ID40 = 60 nmol), but not delta 1 (DALCE: ID40 = 288 nmol) antagonists consistently reduce saccharin intake suggests a role for the delta 2 receptor subtype in the modulation of hedonic orosensory signals.

Involvement of mu1 and mu2 opioid receptor subtypes in tail-pinch feeding in rats

Tail-pinch feeding (TPF) in rats is decreased following general (naltrexone, NTX) and mu (Cys2-Tyr3-Orn5-Pen7-amide, CTOP) opioid antagonists, but not following kappa (nor-binaltorphamine. Nor-BNI) or delta (naltrindole, NTI) opioid antagonists. Because multiple mu (mu1 and mu2) and delta (delta 1 and delta 2) opioid receptor subtypes have been characterized, the present study evaluated whether TPF was differentially altered following ICV administration of general (NTX), mu (beta-funaltrexamine, B-FNA), mu1 (naloxonazine, NAZ), kappa (Nor-BNI), delta 1 ([D-Ala2, Leu5, Cys6]-enkephalin, DALCE) and delta 2 (NTI) opioid antagonists. Like the reversible mu antagonist CTOP, the irreversible mu antagonist B-FNA significantly and dose-dependently (1-20 micrograms) reduced TPF by up to 28%. In contrast, whereas NAZ (50 micrograms) reduced TPF by 32%, this effect was highly variable and failed to achieve significance. Neither NTX (5-10 mg/kg, SC), Nor-BNI (20 micrograms), DALCE (40 micrograms) nor NTI (20 micrograms) significantly altered TPF, suggesting that kappa, delta 1 and delta 2 opioid receptor subtypes were not involved. Because no antagonist altered the duration of food contact during tail pinch, it appears that the opioid effect modulates ingestive rather than activational mechanisms. The reliable inhibition of TPF by B-FNA (mu1 and mu2), together with the variable effect of naloxonazine (mu1), appears to implicate both mu binding sites in this response.

Naltrexone, serotonin receptor subtype antagonists, and glucoprivic intake: 1. 2-Deoxy-D-glucose

Inhibition of deprivation-induced intake by naloxone was significantly enhanced by the 5-hydroxytryptamine3 (5-HT3) antagonist ICS-205,930. Interactions between naloxone and either the general 5-HT antagonist methysergide or the 5-HT2 antagonist ritanserin or ketanserin produced smaller effects. The present study evaluated whether 2-deoxy-D-glucose (2DG, 400 mg/kg) hyperphagia was affected by methysergide (0.5-5 mg/kg), ritanserin (0.25-2.5 mg/kg), or ICS-205,930 (0.5-5 mg/kg) alone or in combination with naltrexone (0.25 and 2.5 mg/kg). Only ICS-205,930 stimulated spontaneous intake for up to 4 h in the light cycle. Only ritanserin (1.25 mg/kg) transiently reduced 2DG hyperphagia. The dose-dependent decreases in 2DG hyperphagia by naltrexone were significantly enhanced by the dose range of ICS-205,930. The inhibition of 2DG hyperphagia by the low naltrexone dose was enhanced by methysergide (5 mg/kg) and ritanserin (1.25 mg/kg). These data suggest that the 5-HT3 receptor primarily interacts with opioid systems to modulate 2DG hyperphagia and that one possible locus of interaction is in the caudal brainstem.

Naltrexone, serotonin receptor subtype antagonists, and glucoprivic intake: 2. Insulin

Opiate antagonist inhibition of deprivation-induced intake and 2-deoxy-D-glucose (2DG) hyperphagia is significantly enhanced by the 5-hydroxytryptamine3 (5-HT3) antagonist, ICS-205,930. Interactions between opiate antagonists and either 5-HT or 5-HT2 antagonists produced smaller effects. The present study evaluated whether insulin (5 U/kg) hyperphagia was affected by methysergide (0.5-5 mg/kg), ritanserin (0.25-2.5 mg/kg), and ICS-205,930 (0.5-5 mg/kg) alone or in combination with naltrexone (2.5-10 mg/kg). Whereas ICS-205,930 stimulated insulin hyperphagia across the 6-h time course, ritanserin and, to a lesser degree, methysergide reduced insulin hyperphagia. Naltrexone marginally (19-33%) reduced insulin hyperphagia. Pairing naltrexone with either ICS-205,930 or ritanserin significantly suppressed insulin hyperphagia after 2 h. Pairing naltrexone with each of the serotonin antagonists significantly enhanced insulin hyperphagia after 4 and 6 h. These data suggest that 5-HT2 and 5-HT3 receptor subtypes interact with opioid systems to modulate insulin hyperphagia. Given that central insulin reduces food intake and body weight, the interaction between serotonergic and opioid systems may occur peripherally.

Naloxone benzoylhydrazone, a kappa 3 opioid agonist, stimulates food intake in rats

Naloxone benzoylhydrazone (NalBzoH) is a selective, short-acting agonist at the kappa 3 opioid receptor and a slowly dissociating potent antagonist at the mu opioid receptor. Given the important role of kappa receptors in the opioid control of food intake, the present study examined the central and peripheral effects of NalBzoH upon food intake. Central administration of NalBzoH (1-20 micrograms, i.c.v.) significantly increased food intake for up to 12 h, but failed to alter intake or body weight after 24 or 48 h. The 12 h duration of NalBzoH-mediated effects may be due to either persistent kappa 3 receptor occupancy, and/or activation of an ingestive system which maintains its activity. Peripheral administration of NalBzoH (20 mg/kg, s.c.) significantly increased food intake for up to 1 h. To distinguish kappa 1 (U50,488H) and kappa 3 (NalBzoH) hyperphagic effects, these agonist effects were compared following pretreatment with either naltrexone or the kappa 1 antagonist, nor-binaltorphamine (Nor-BNI). Whereas naltrexone significantly reduced both U50,488H and NalBzoH hyperphagia, Nor-BNI blocked U50,448H, but not NalBzoH hyperphagia. These data indicate a distinct role for the kappa 3 receptor in ingestive behavior separable from that of kappa 1 effects.

Potentiation of 2-deoxy-D-glucose antinociception, but not hyperphagia by zolantidine, a Histamine (H2) receptor antagonist

Antagonism of the histamine (H2) receptor reduces antinociception induced by naloxone-resistant foot-shock, naloxone-sensitive foot-shock, and morphine with a rank-order potency similar to their H2 antagonism. The antimetabolic glucose analog 2-deoxy-D-glucose (2DG) produces antinociceptive and hyperphagic responses that dissociate from each other and are in part mediated by opioid systems. The present study determined the effects of the brain-penetrating H2 receptor antagonist zolantidine (ZOL) on 2DG antinociception on the tail-flick and jump tests, as well as on 2DG hyperphagia, in rats. ZOL (0.01-1 mg/kg) potentiated the antinociceptive responses induced by a moderate (450 mg/kg) dose of 2DG, but had lesser effects upon antinociception induced by a lower (100 mg/kg) 2DG dose. ZOL itself slightly increased jump thresholds, but not tail-flick latencies. Combinations of ZOL and 2DG produced supraadditive antinociception, even though ZOL failed to significantly shift the 2DG dose-response curve to the left. In contrast, ZOL failed to alter basal intake or 2DG hyperphagia, supporting previous evidence implicating the H1 but not the H2 receptor in these effects. These results further dissociate the antinociceptive and hyperphagic effects of 2DG, and also support previous results indicating both pro- and antinociceptive roles for H2 receptors.

Evaluation of the antianginal effect of isosorbide-5-mononitrate in patients with chronic stable angina pectoris

The antianginal and anti-ischemic properties of isosorbide-5-mononitrate (ISMN) were evaluated in 40 patients with chronic stable angina pectoris in a randomized double-blind parallel-group placebo-controlled study. After 2 weeks' placebo run-in period the patients were randomized to either ISMN, orally 20 mg 2-3 times daily (titrated) or placebo. They underwent bicycle exercise stress test at the end of the placebo period and after 4 weeks of treatment. Compared with placebo ISMN increased the exercise performance, reduced ST-segment depression, anginal frequency and sublingual nitroglycerin consumption. All these changes were statistically significant. It may be concluded that ISMN is an effective antianginal and anti-ischemic agent in patients with chronic stable angina pectoris.

Treatment of angina pectoris with isosorbide-5-mononitrate. A multicenter study in general practice

In this multicenter study 191 practitioners treated 532 patients with coronary artery disease and chronic stable angina pectoris by isosorbide-5-mononitrate (IS-5-MN), 20 mg 2-3 times daily. At the end of this period the frequency of anginal attacks was reduced by 83% and nitroglycerin consumption by 85.7% (p less than 0.0001). 40.1% of the patients categorized this treatment as very good, 28.6% as excellent and 23% as good. Serious adverse effects were observed in 2% of the patients and 6.4% of the patients discontinued treatment during the study because of inefficacy, infarction, death, or adverse effects. At the end of the study 90.2% of the patients were still on IS-5-MN. In conclusion, IS-5-MN is an effective treatment for patients with chronic stable angina pectoris. It is well tolerated, with minimal side effects.

In situ hybridization analysis of isodicentric X-chromosomes with short arm fusion

We present here an alternative approach to the study of mosaic cell lines containing dicentric chromosomes. The approach is based on chromosome-specific non-radioactive in situ hybridization with centromere (alpha satellite DNA) probes. The hybridization analysis may be used as an alternative to the C-band analysis, while at the same time to some extent replacing the Q-band analysis as well. The advantage of using in situ hybridization is mainly that it allows the very fast screening of a large number of metaphases. We illustrate this new application of the technique by using it for the analysis of two cases of isodicentric X-chromosomes. The approach is expected to be generally applicable, so that it may be applied to the scoring of other types of chromosomal mosaicism as well.

Oligonucleotide-priming methods for the chromosome-specific labelling of alpha satellite DNA in situ

It is demonstrated that either general staining of the centromeric regions of all primate chromosomes, or selective staining of the centromeric region of specific chromosomes, may be obtained in preparations of metaphase chromosomes by probing specifically for different regions within the alpha satellite DNA monomer. In order to exploit observed patterns of sequence variation within the monomer for this purpose, we have developed two new DNA analysis methods. In PRimed IN Situ labelling (PRINS), synthetic oligonucleotides derived from subsections of the monomer are hybridized to the chromosomes. The oligonucleotides then serve as primers for the in situ incorporation of biotin-labelled nucleotides catalysed by Klenow polymerase. Incorporated biotin is visualized with fluorescein isothiocyanate-labelled avidin (FITC-avidin). In Primed Amplification Labelling (PAL), biotin-labelled hybridization probes are produced in a polymerase chain reaction (PCR, Saiki et al. 1985), in which two synthetic oligonucleotide primers anneal within the same monomer. With the right choice of primers libraries of labelled probes derived from most monomers present as templates are produced. If DNA from a specific chromosome is used as template, then the resulting probe mixture gives stronger and more chromosome-specific signals in in situ hybridization experiments than does a cloned alpha satellite DNA probe derived from the same chromosome. The results obtained indicate that the alpha-repeat monomer is composed of regions with different degrees of chromosome specificity.

Treatment of genomic DNA with T4 DNA ligase improves Southern blot analysis

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