Marchigian Sardinian alcohol-preferring (msP) rats exhibit innate preference for alcohol, are highly sensitive to stress and stress-induced alcohol seeking. Genetic analysis showed that over-expression of the corticotropin-releasing factor (CRF) system of msP rats is correlated with the presence of two single nucleotide polymorphisms (SNPs) occurring in the promoter region (position −1836 and −2097) of the CRF1 receptor (CRF1-R) gene. Here we examined whether these point mutations were associated to the innate alcohol preference, stress-induced drinking, and seeking. We have recently re-derived the msP rats to obtain two distinct lines carrying the wild type (GG) and the point mutations (AA), respectively. The phenotypic characteristics of these two lines were compared with those of unselected Wistar rats. Both AA and GG rats showed similar patterns of voluntary alcohol intake and preference. Similarly, the pharmacological stressor yohimbine (0.0, 0.625, 1.25, and 2.5 mg/kg) elicited increased operant alcohol self-administration under fixed and progressive ratio reinforcement schedules in all three lines. Following extinction, yohimbine (0.0, 0.625, 1.25, and 2.5 mg/kg) significantly reinstated alcohol seeking in the three groups. However, at the highest dose this effect was no longer evident in AA rats. Treatment with the CRF1-R antagonist antalarmin (0, 5, 10, and 20 mg/kg) significantly reduced alcohol-reinforced lever pressing in the AA line (10 and 20 mg/kg) while a weaker or no effect was observed in the Wistar and the GG group, respectively. Finally, antalarmin significantly reduced yohimbine-induced increase in alcohol drinking in all three groups. In conclusion, these specific SNPs in the CRF1-R gene do not seem to play a primary role in the expression of the msP excessive drinking phenotype or stress-induced drinking but may be associated with a decreased threshold for stress-induced alcohol seeking and an increased sensitivity to the effects of pharmacological blockade of CRF1-R on alcohol drinking.

Marchigian-Sardinian alcohol-preferring (msP) rats exhibit innate preference for alcohol along with anxious phenotype. In these animals, two single nucleotide polymorphisms in position −1836 and −2097 from the first start codon of the CRF1-R transcript have been found. Here we examined whether these point mutations account for the heightened anxiety-like behavior and stress responsiveness of msP rats. We re-derived the msP rats to obtain two distinct lines carrying the wild type (GG) and point mutations (AA), respectively. CRF1-R gene expression analysis revealed significant dysregulation of the system in the extended amygdala of AA rats. At the behavioral level, using the elevated plus maze, we found that both AA and GG lines had higher basal anxiety compared to Wistar rats. In the defensive burying test, AA rats showed decreased burying behavior compared to the GG and the unselected Wistar lines. Freezing/immobility did not differ among AA and GG but was higher than that of Wistars. The selective CRF1-R antagonist antalarmin (0, 10, 20 mg/kg) reduced burying behavior in Wistar animals. However, antalarmin (10 mg/kg) tended to increase rather than reducing this behavior when tested in the msP lines, an effect that appeared more marked in the GG as compared to the AA line. The present data suggest that rats with msP genetic background are more anxious and show different sensitivity to stress and CRF1-R blockade than Wistars. The point mutations occurring in the CRF1-R gene do not seem to influence basal anxiety while they appear to affect active responses to stress.

Objectives: This study was aimed at determining the effect of folic acid adjunct therapy on homocysteine (HCY) and blood pressure (BP) levels in hypertensive subjects. Method: The study was a double blind placebo-controlled trial on 100 hypertensive patients randomised into 50 folate and 50 placebo groups, where the folate group had 5 mg folic acid daily for 8 weeks. Fasting plasma homocysteine, folate and blood pressure levels were determined at baseline, at 4 and at 8 weeks. The Mixed Model Repeated Measures analysis of variance was applied for data analysis. Results: Hyperhomocysteinaemia was found at baseline in the folate (21.3 ± 5.7 µmol/L) and placebo (21.6 ± 4.9 µmol/L) groups which did not differ statistically (p > 0.05). Folic acid adjunct therapy, reduced homocysteine levels at 4 weeks by 2.0 µmol/L (9.2 %, p < 0.05) and at 8 weeks by 1.2 µmol/L (5.6 %, p < 0.05), with no significant (p > 0.05) systolic and diastolic blood pressure lowering effect. High base-line folate levels were found in both folate (113.8 ± 51.2 ng/ml) and placebo groups (109.5 ± 51.4 ng/ml) with no statistically significant difference (p > 0.05). Conclusion: Short-term daily folic acid supplementation over 8 weeks had a significant homocysteine reduction effect with no significant reduction in systolic and diastolic blood pressures of hypertensive subjects in Zaria, Nigeria. Hyperhomocysteinaemia could not be accounted for by suboptimal folate levels. Keywords: Hypertension, Homocysteine, Blood pressure, Folate, Placebo, Nigeria.

The leaf of Nymphaea lotus has been used traditionally for the management of pain and inflammatory diseases. The methanol leaf extract of Nymphaea lotus (NLE) was evaluated for possible anti-nociceptive and anti-inflammatory activities in rats and mice (at the doses of 250, 500 and 1,000 mg/kg) to investigate the existence of scientific basis for the folkloric use of the plant. The standard drugs used were piroxicam (10 mg/kg) and morphine (10 mg/kg). The possible pharmacological mechanism involved in the anti-nociceptive activity was also investigated. The acute toxicity was determined in mice and rats using method of Lorke. The anti-nociceptive activity was evaluated using acetic acid-induced writhing and hot plate tests in mice, while the anti-inflammatory activity was evaluated using carrageenan-induced hind paw edema model in rats. The oral median lethal dose of NLE was found to be greater than 5,000 mg/kg in rats and mice. NLE demonstrated significant and dose-dependent protection against acetic acid induced writhes and increased the reaction time of mice in hot plate test. Pretreatment of the animals with naloxone (2 mg/kg) significantly ( p < 0.05) attenuated the anti-nociception elicited by both NLE and morphine. NLE at the doses of 250 and 1,000 mg/kg significantly ( p < 0.05) decreased rat paw edema at the 2 nd hour in the carrageenan-induced paw edema test. The result of the study revealed that Nymphaea lotus possesses anti-nociceptive activities which may be mediated via the opioidergic system as well as mild anti-inflammatory activities thus providing scientific basis for the use of the plant in the management of pain and inflammatory diseases.

BACKGROUND AND PURPOSESubstance P and its preferred neurokinin receptor NK 1 have been implicated in stress and anxiety and have been proposed as possible therapeutic targets for the treatment of anxiety/depression. Attention is also being focused on the role this neuropeptide system may play in drug addiction, because stress-related mechanisms promote drug abuse. EXPERIMENTAL APPROACHThe effects of the rat-specific NK 1 receptor antagonist, L822429, on alcohol intake and seeking behaviour was investigated in genetically selected Marchigian Sardinian alcohol preferring rats. These rats demonstrate an anxious phenotype and are highly sensitive to stress and stress-induced drinking. KEY RESULTSSystemic administration of L822429 significantly reduced operant alcohol self-administration in Marchigian Sardinian alcohol preferring rats, but did not reduce alcohol self-administration in stock Wistar rats. NK 1 receptor antagonism also attenuated yohimbine-induced reinstatement of alcohol seeking at all doses tested but had no effect on cue-induced reinstatement of alcohol seeking. L822429 reduced operant alcohol self-administration when injected into the lateral cerebroventricles or the medial amygdala. L822429 injected into the medial amygdala also significantly reduced anxiety-like behaviour in the elevated plus maze test. No effects on alcohol intake were observed following injection of L822429 into the dorsal or the ventral hippocampus. Conclusions and Implications Our results suggest that NK 1 receptor antagonists may be useful for the treatment of alcohol addiction associated with stress or comorbid anxiety disorders. The medial amygdala appears to be an important brain site of action of NK 1 receptor antagonism.