Background and purpose: In addition to a 1A , a 1B and a 1D -adrenoceptors (ARs), putative a 1L -ARs with a low affinity for prazosin have been proposed. The purpose of the present study was to identify the a 1A -AR and clarify its pharmacological profile using a radioligand binding assay.
Conclusions and implications:The present study clearly reveals the presence of a 1L -ARs as a pharmacologically distinct entity from a 1A and a 1B -ARs in intact tissue segments of rat cerebral cortex but not tail artery. However, the a 1L -ARs disappeared after tissue homogenization, suggesting their decomposition and/or their pharmacological profile changes to that of a 1A -ARs.
Abstract. Muscarinic receptors in the human and rat lower urinary tract (urinary bladder detrusor muscle and mucosa, and prostate) were identified by intact tissue segment binding assays with two radioligands, and the effects of prolonged receptor activation in vitro on muscarinic receptors were examined. Hydrophilic [3 H]-NMS and hydrophobic [ 3 H]-QNB bound to the detrusor muscle segments with the same density, suggesting that the muscarinic receptors were localized at the plasma membrane. While the density of muscarinic receptor was higher in detrusor muscle than in the bladder mucosa and prostate, there was no species-specific difference either in density or in subtype distribution (M 1 , M 2 , and M 3 subtypes in detrusor; M 2 and M 3 subtypes in bladder mucosa; and M 1 and M 2 subtypes in prostate). Incubation of detrusor strips with carbachol decreased [3 H]-NMS binding sites within 20 min, followed by a reduction of [ 3 H]-QNB binding sites after a 60-min lag phase. The loss of the binding sites over 3 h after carbachol treatment was the same (approximately 40%) for both radioligands. The present intact tissue segment binding assay reveals tissue-specific and plasma membrane distribution of distinct muscarinic receptor subtypes and their dynamic changes (internalization and down-regulation) in lower urinary tract of humans and rats.
Carbon tetrachloride (CCl4) is a colorless liquid organic compound which is used for household work. Mainly liver and kidney of human are the major organs for CCl4 toxicity. Liver can damage after 24 hours of CCl4 ingestion and can cause severe fatal symptoms including painful swollen liver, hemorrhages, hepatic coma leading to death. We examined the effect of CCl4 on rat liver. Serum glutamic pyruvic transaminase (SGPT) and serum bilirubin levels are used as a biomarker for the hepatotoxicity. Our goal was to determine the effect of SGPT and bilirubin level by using methanolic extract of Achyranthes aspera (Amaranthaceae) roots and barks on CCl4 induced rats. After completing the fractionation process these extracts was induced in the rat's body in a dose dependent manner. Our result demonstrated that carbon tetrachloride caused the hepatotoxicity in rats where 1 ml/kg body weight of carbon tetrachloride significantly increased the SGPT and bilirubin level in one day treatment, while 0.25 ml/kg and 0.50 ml/ kg body weight of CCl4 on one day treatment did not have significant effect on SGPT and bilirubin level. But the low dose of CCl4 such as 0.5 ml/kg of body weight for longer period treatment caused the hepatotoxicity. CCl4 induced controlled group was treated with dexamethasone 2.0 mg/kg, 4mg/kg, 6.0 mg/kg, 8 mg/kg body weight to compare with plant extract activity. A significant result was found that the methanolic extract of root is responsive against CCl4 induced hepatotoxicity where the doses were 10mg/kg, 20mg/kg and 30 mg/kg.
Dysfunctions in memory recall lead to pathological fear; a hallmark of trauma-related disorders, like posttraumatic stress disorder (PTSD). Both, heightened recall of an association between a cue and trauma, as well as impoverished recall that a previously trauma-related cue is no longer a threat, result in a debilitating fear toward the cue. Glucocorticoid-mediated action via the glucocorticoid receptor (GR) influences memory recall. This literature has primarily focused on GRs expressed in neurons or ignored cell-type specific contributions. To ask how GR action in nonneuronal cells influences memory recall, we combined auditory fear conditioning in mice and the knockout of GRs in astrocytes in the prefrontal cortex (PFC), a brain region implicated in memory recall. We found that knocking out GRs in astrocytes of the PFC disrupted memory recall. Specifically, we found that knocking out GRs in astrocytes in the PFC (AstroGRKO) after fear conditioning resulted in higher levels of freezing to the CS+ tone when compared with controls (AstroGRintact). While we did not find any differences in extinction of fear toward the CS+ between these groups, AstroGRKO female but not male mice showed impaired recall of extinction training. These results suggest that GRs in cortical astrocytes contribute to memory recall. These data demonstrate the need to examine GR action in cortical astrocytes to elucidate the basic neurobiology underlying memory recall and potential mechanisms that underlie female-specific biases in the incidence of PTSD.
Abstract:The use of formalin (40% formaldehyde) for the preservation of food in an illegal way becoming a serious health issue in developing countries including Bangladesh. We investigated the Formalin (FA)-induced organ toxicity in Swiss albino mice. FA induction caused the significant elevation of the liver enzyme, SGOT and SGPT; the MDA levels in the liver and brain. Among the fractions of methanol extract of L. globosus, ethyl acetate (EA) fraction significantly reduced the elevated biochemical parameters (FA vs FA + EA fraction, µKa/L); SGOT (78.4 ± 0.3 vs 14.3 ± 0.9), SGPT (100.5 ± 5.2 vs 14.6 ± 0.7), MDA in liver (10.9 ± 0.2 vs 5.6 ± 0.1) and MDA in brain (16.9 ± 0.2 vs 6.3 ± 0.2). Morphological analyses also supported the beneficial effect of EA fraction in FA-induced liver toxicity. FA induction caused the phosphorylation of JNK, member of mitogen activated protein kinase (MAPK) in both the liver and brain, which were completely abolished by the treatment of EA fraction of L. globosus. Chemical analyses showed that the EA fraction exhibited antioxidant and free radical scavenging properties. The protective effect of the EA fraction on the FA-induced toxicity by the modulation of oxidative inflammatory pathway by its antioxidant and free radical scavenging activity.
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