This work investigated the effect of the H1 receptor blockade in the forebrain of ablated Carassius auratus in a simple stimulus-response learning task using a T-maze test with positive reinforcement. The goldfish were submitted to surgery for removal of both telencephalic lobes five days before beginning the experiment. A T-shaped glass aquarium was employed, with two feeders located at the ex...

in the present study, the effects of intracerebroventricular (icv) injections of histamine, chlorpheniramine (h1-receptor antagonist) and ranitidine (h2-receptor antagonist) were investigated on visceral nociception induced by an intraperitoneal (ip) injection of acetic acid in rats. the latency time to the beginning of the first abdominal wall contraction (the first writhe) was recorded and th...

In the present study a series of 1-substituted-4-(2-methoxyphenyl)-s-triazolo[4,3-a]quinazolin-5(4H)-ones were synthesized and are screened for their H1-antihistaminic activity. The synthesized compounds were characterized by IR, H-NMR and mass spectral data; the purity of the compounds was determined by elemental analysis. Antihistaminic activity of the title compounds was evaluated by histami...

Helical strips of human coronary arteries contracted in response to histamine concentration dependently, they relaxed with low concentrations and contracted with high concentrations. Treatment with cimetidine potentiated contraction in the strips with intact and damaged endothelium to a similar extent and attenuated relaxation. Removal of endothelium abolished relaxation and potentiated contrac...

OBJECTIVE Allergic rhinitis is common and on the rise. Antihistamines are the mainstay of treatment and are the most commonly prescribed drugs in Singapore. Treatment-related sedation and its effect on cognition are a major concern. First- and second-generation antihistamines show varying degrees of sedation, but to date, objective studies in children are lacking. The objective of this study wa...

The performance of different chemometric approaches was evaluated in the spectrophotometric determination of pharmaceutical mixtures characterized by having the amount of components with a very high ratio. Principal component regression (PCR), partial least squares with one dependent variable (PLS1) or multi-dependent variables (PLS2), and multivariate curve resolution (MCR) were applied to the...

COVID-19 disease is caused by the Betacoronavirus, SARS-CoV-2. This virus gave rise to 676 million confirmed cases with 6.9 deaths worldwide early 2023. After first appearing in Wuhan, China late 2019, has mutated into seven successive major forms progressive increases infectivity: Alpha, Beta, Delta, Omicron, and Omicron variants BA.4, BA.5, XBB.1.5. Liposomal mRNA vaccines have been developed...

Histaminergic fibers are present in the molecular and granular layers of the cerebellum and have a high density in the vermis and flocullus. Evidence supports that the cerebellar histaminergic system is involved in memory consolidation. Our recent study showed that histamine injections facilitate the retention of an inhibitory avoidance task, which was abolished by pretreatment with an H2 recep...