Zantac Research Today is a free monthly online journal that collates and summarizes the latest research about Zantac, including details on ranitidine, side-effects, allergic reactions, information.

Withdrawal from repeated administration of morphine alters histamine-induced anxiogenic effects produced by intra-ventral hippocampal microinjection.

Zarrindast MR, Khodarahmi P, Rezayof A, Oryan S

Department of Pharmacology, School of Medicine and Iranian National Center for Addiction Studies,Tehran University of Medical Sciences.

In the present study, the influence of withdrawal from repeated administration of morphine on intra-ventral hippocampal microinjection of histamine-induced anxiety-like behavior was investigated in male Wistar rats. Three days subcutaneous administration of morphine (5-10 mg/kg) followed by five days free of the drug decreased the percentage open arm time and the percentage open arm entries. Intra-ventral hippocampal administration of histamine (2.5-7.5 microg/rat) decreased percentage open arm time and percentage open arm entries. Intra-ventral hippocampal histamine-induced anxiogenic effect was reversed in animals that had previously received the three days morphine (7.5 mg/kg) followed by five days free of the drug. Intra-ventral hippocampal administration of pyrilamine (5-20 microg/rat) or ranitidine (10-40 microg/rat) decreased percentage open arm time and percentage open arm entries. Pyrilamine- or ranitidine-induced anxiogenic effect was not changed in animals that had previously received the three days morphine (7.5 mg/kg) followed by five days free of the drug. Intra-ventral hippocampal injections of clobenpropit increased percentage open arm time. The percentage open arm time and percentage open arm entries were decreased in the morphine-treated animals compared with non-morphine-treated controls. Percentage open arm entries and locomotor activity was reduced with some doses of clobenpropit. It can be concluded that the histamine system is involved in anxiety-like behavior, and repeated injections of morphine followed by five days free of the drugs interact with histamine receptor mechanism.

Published 22 January 2010 in J Psychopharmacol.
Full-text of this article is available online (may require subscription).

Articles on Zantac published 21 January 2010:

Histamine stimulates interleukin-6 production through histamine H1 receptors in human amnion cells.   Gynecol Obstet Invest, 69(1): 67-72.

BACKGROUND/AIMS: Previous studies have stated that maternal allergic diseases are associated with increased risk of preterm labor/delivery, but the underlying mechanisms remain unclear. This study tested the hypothesis that histamine induces interleukin (IL)-6 production in amnion cells. METHODS: Using cultured human amnion cells, we examined expression of histamine receptors and effects of histamine on IL-6 production. RESULTS: Reverse transcription-polymerase chain reaction and Western ... [Abstract] [Full-text]

Ranitidine as an alcohol dehydrogenase inhibitor in acute methanol toxicity in rats.   Hum Exp Toxicol, 29(2): 93-101.

Methanol poisoning is a hazardous intoxication characterized by visual impairment and formic acidemia. The therapy for methanol poisoning is alcohol dehydrogenase (ADH) inhibitors to prevent formate accumulation. Ranitidine has been considered to be an inhibitor of both gastric alcohol and hepatic aldehyde dehydrogenase enzymes. This study aimed at testing ranitidine as an antidote for methanol acute toxicity and comparing it with ethanol and 4-methyl pyrazole (4-MP). This study was conducted ... [Abstract] [Full-text]

Articles on Zantac published 18 January 2010:

Simultaneous quantitative analysis of fasudil and its active metabolite in human plasma by liquid chromatography electro-spray tandem mass spectrometry.   J Pharm Biomed Anal.

A fast and sensitive method to quantify fasudil hydrochloride (FH) and its active metabolite hydroxyfasudil (M3) in human plasma using HPLC-MS/MS has been developed and validated in present study. The method involved simple sample preparation with methanol as protein precipitation (3:1, v/v) and ranitidine as an internal standard (IS). The analytes and IS were separated using a gradient elution procedure on the analytical column ZORBAX StableBond-C18 (5mum, 150mmx4.6mm). Detection was performed ... [Abstract] [Full-text]

Articles on Zantac published 14 January 2010:

Hepatoprotective, antinociceptive and antioxidant activities of cimetidine, ranitidine and famotidine as histamine H receptor antagonists.   Fundam Clin Pharmacol.

Abstract The antioxidant, antinociceptive and hepatoprotective effects of H(2) receptor blockers were examined with different experimental models. Antioxidant activities were determined by employing various in vitro assay systems such as 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical-scavenging activity assays, reducing power determination assays, nitric oxide-scavenging activity assays and hydrogen peroxide-scavenging activity assays. Antinociceptive effects were determined using the hot plate ... [Abstract] [Full-text]

Articles on Zantac published 11 January 2010:

H(4) receptor antagonism exhibits anti-nociceptive effects in inflammatory and neuropathic pain models in rats.   Pharmacol Biochem Behav.

The histamine H(4) receptor (H(4)R) is expressed primarily on cells involved in inflammation and immune responses. To determine the potential role of H(4)R in pain transmission, the effects of JNJ7777120, a potent and selective H(4) antagonist, were characterized in preclinical pain models. Administration of JNJ7777120 fully blocked neutrophil influx observed in a mouse zymosan-induced peritonitis model (ED(50)=17mg/kg s.c., 95% CI=8.5-26) in a mast cell-dependent manner. JNJ7777120 potently ... [Abstract] [Full-text]

Articles on Zantac published 6 January 2010:

Stress ulcer, gastritis, and gastrointestinal bleeding prophylaxis in critically ill pediatric patients: a systematic review.   Pediatr Crit Care Med, 11(1): 124-32.

OBJECTIVE: To identify and evaluate the quality of evidence supporting prophylactic use of treatments for stress ulcers and upper gastrointestinal bleeding. Stress ulcers, erosions of the stomach and duodenum, and upper gastrointestinal bleeding are well-known complications of critical illness in children admitted to the pediatric intensive care unit. DATA SOURCES: Studies were identified from the Cochrane Central Register of Controlled Trials, PUBMED; LILACS; Scirus. We also scanned ... [Abstract] [Full-text]

Articles on Zantac published 5 January 2010:

Pediatric specialists' beliefs about gastroesophageal reflux disease in premature infants.   Pediatrics, 125(1): 96-104.

BACKGROUND: Wide variation exists in the treatment of suspected gastroesophageal reflux disease (GERD) in premature infants; it is unknown to what degree diagnosis and treatment are affected by the treating physician's medical specialty or interpretation of the medical literature. METHODS: This study involved an online survey of board-certified neonatologists, pediatric pulmonologists, and pediatric gastroenterologists about their beliefs regarding the symptoms, diagnosis, and treatment of GERD ... [Abstract] [Full-text]

Articles on Zantac published 21 December 2009:

Factors influencing pharmacokinetics of prophylactic posaconazole in patients undergoing allogeneic stem cell transplantation.   Antimicrob Agents Chemother, 54(1): 207-12.

The objectives of the present study were to elucidate the factors influencing the pharmacokinetics of prophylactically administered posaconazole in allogeneic hematopoietic stem cell transplant (SCT) recipients. Between May 2007 and November 2008, clinical data were obtained from all SCT recipients at the University Hospital of Cologne undergoing therapeutic drug monitoring (TDM) of serum prophylactic posaconazole concentrations. The posaconazole concentrations were determined by ... [Abstract] [Full-text]

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