Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Corticotropin releasing factor (CRF) is the primary regulator of the hypothalamus-pituitary-adrenal (HPA) axis, coordinating the endocrine, behavioral, and autonomic responses to stress. It has been postulated that small molecules that can antagonize the binding of CRF1 to its receptor may serve as a treatment for anxiety-related and/or affective disorders. Members within a series of 3,4-dihydro-1H-pyrido[2,3-b]pyrazin-2-ones, exemplified by compound 2 (IC50 = 0.70 nM), were found to be very potent antagonists of CRF1. Compound 8w showed high CRF1 receptor binding affinity and was examined further in vivo. The compound was efficacious in a defensive withdrawal model of anxiety in rats and had a long half-life and reasonable oral bioavailability in dog pharmacokinetic studies.
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Mutations in the gene for leucine-rich repeat kinase 2 (LRRK2) have been linked to several familial and sporadic late-onset cases of Parkinson's disease. The cumulative data for the effects of mutant forms of this enzyme on neuronal degradation and the pathophysiology of Parkinson's disease create a compelling case for drug discovery based on inhibition of the mutant forms of LRRK2. This review focuses on structure-activity relationships for inhibitors of LRRK2 and the data supporting a potential role of these agents in treating Parkinson's disease. Keywords: Kinase inhibitors, Leucine-rich repeat kinase 2 (LRRK2), Parkinson's disease.
The in vitro pharmacological profile of a novel small molecule corticotropin-releasing factor 1 (CRF(1)) receptor antagonist, (+/-)-N-[2-methyl-4-methoxyphenyl]-1-(1-(methoxymethyl)propyl)-6-methyl-1H-1,2,3-triazolo[4,5-c]pyridin-4-amine (SN003), and the characteristics of its radioligand ([(3)H]SN003) are described. SN003 has high affinity and selectivity for CRF(1) receptors expressed in rat cortex, pituitary, and recombinant HEK293EBNA (HEK293e) cells with respective radiolabeled ovine CRF ([(125)I]oCRF) binding K(i) values of 2.5, 7.9, and 6.8 nM. SN003 was shown to be a CRF(1) receptor antagonist inasmuch as it inhibited CRF-induced cAMP accumulation in human CRF(1)HEK293e cells and CRF-stimulated adrenocorticotropin hormone release from rat pituitary cells without agonist activities. Significant decreases in the B(max) of [(125)I]oCRF binding by SN003 suggest that this antagonist is not simply competitive. To further explore the interaction of SN003 with the CRF(1) receptors, [(3)H]SN003 binding to rat cortex and human CRF(1)HEK293e cell membranes was characterized and shown to be reversible and saturable, with K(D) values of 4.8 and 4.6 nM, and B(max) values of 0.142 and 7.42 pmol/mg protein, respectively. The association and dissociation rate constants of [(3)H]SN003 (k(+1) 0.292 nM(-1) min(-1) and k(-1) 0.992 x 10(-2) min(-1)) were also assessed using human CRF(1)HEK293e cell membranes, giving an equilibrium dissociation constant of 3.4 nM. Moreover, [(3)H]SN003 binding displayed a single affinity state and insensitivity to 5'-guanylylimidodiphosphate, consistent with characteristics of antagonist binding. Incomplete inhibition of [(3)H]SN003 binding by CRF peptides also suggests that SN003 is not simply competitive with CRF at CRF(1) receptors. The distribution of [(3)H]SN003 binding sites was consistent with the expression pattern of CRF(1) receptors in rat brain regions. Small molecule CRF(1) antagonist radioligands like [(3)H]SN003 should enable a better understanding of small molecule interactions with the CRF(1) receptor.
Life-history theory and evolutionary theories of aging assume the existence of alleles with age-specific effects on fitness. While various studies have documented age-related changes in the genetic contribution to variation in fitness components, we know very little about the underlying genetic architecture of such changes. We used a set of recombinant inbred lines to map and characterize the effects of quantitative trait loci (QTL) affecting fecundity of Drosophila melanogaster females at 1 and 4 weeks of age. We identified one QTL on the second chromosome and one or two QTL affecting fecundity on the third chromosome, but these QTL affected fecundity only at 1 week of age. There was more genetic variation for fecundity at 4 weeks of age than at 1 week of age and there was no genetic correlation between early and late-age fecundity. These results suggest that different loci contribute to the variation in fecundity as the organism ages. Our data provide support for the mutation accumulation theory of aging as applied to reproductive senescence. Comparing the results from this study with our previous work on life-span QTL, we also find evidence that antagonistic pleiotropy may contribute to the genetic basis of senescence in these lines as well.
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