RESUMEN
Synthesis of 9-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl)-adenine (7, ara-A2'F) and -guanine (12, ara-G2'F) was accomplished via the condensation of 2,6-dichloropurine (1) with 2-deoxy-2-fluoro-1,3,5-tri-O-benzoyl-alpha-D-arabinofuranose (2) as a key chemical step. Condensation of silylated N6-benzoyladenine (6) with 2 gave, after deblocking and chromatographic separation, ara-A2'F (7) (14%), it's alpha-anomer 8 (14%) and N7-alpha-isomer 9 (25%). The PSEUROT analysis of N9-betaD-arabinosides 7 and 12 manifested slight preference for the S rotamer (64%) for the former, and an equal population of the N and S rotamers for the latter. The arabinosides 7 and 12 were used for the preparation of the respective phosphoamidite building blocks 13 and 14 for automated oligonucleotide synthesis. Four 15-mer oligonucleotides (ONs) complementary to the initiation codon region of firefly luciferase mRNA were prepared: unmodified 2'-deoxy-ON (AS 1) and containing (i) ara-A2'F instead of the only A (AS2), (ii) ara-G2'F vs. 3-G from the 5'-terminus (AS3), and (iii) both arabinosides at the same positions (AS4). All these ONs display practically the same (i) affinity to both complementary DNA and RNA, and (ii) ability to inhibit a luciferase gene expression in a cell-free transcription-translation system.
Asunto(s)
Arabinonucleósidos/química , Hibridación de Ácido Nucleico , Oligonucleótidos Antisentido/química , Oligonucleótidos Antisentido/síntesis química , Oligonucleótidos/química , Secuencia de Bases , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Luciferasas/genética , Espectroscopía de Resonancia Magnética , Oligonucleótidos Antisentido/farmacología , TermodinámicaRESUMEN
The brain content of dopamine (DA) and its metabolites [dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA)] were the same in rats with different immobilization times in forced swimming test, while the serotonin (5-HT) concentration was higher in high active (HA, immobilization < 2 min) than low active (LA, immobilization > 5 min) animals. Ethanol (2 g/kg, PO) tended to increase the DA level in the striatum and nucleus accumbens in LA rats and decrease the 5-HT and 5-hydroxyindoleacetic acid (5-HIAA) concentration in HA rats. delta-Sleep-inducing peptide (DSIP) injection reduced the level of 5-HT in the medial prefrontal cortex (MFC) in both groups, did not affect the concentration of DA or DOPAC, but increased HVA in the striatum of HA rats. DSIP injected before ethanol administration augmented the ethanol effects on 5-HT in the MFC and attenuated the action of ethanol on 5-HIAA in the nucleus accumbens. A relationship between the different levels of voluntary alcohol consumption and sensitivity to stress among LA and HA rats and the differences in DA and 5-HT concentrations is suggested. The use of LA and HA rats in developing models for testing of stress-shielding compounds is also described.
Asunto(s)
Monoaminas Biogénicas/metabolismo , Química Encefálica/efectos de los fármacos , Péptido Inductor del Sueño Delta/farmacología , Etanol/farmacología , Ácido 3,4-Dihidroxifenilacético/metabolismo , Consumo de Bebidas Alcohólicas , Animales , Cromatografía Líquida de Alta Presión , Cuerpo Estriado/efectos de los fármacos , Cuerpo Estriado/metabolismo , Dopamina/metabolismo , Electroquímica , Ácido Homovanílico/metabolismo , Masculino , Núcleo Accumbens/efectos de los fármacos , Núcleo Accumbens/metabolismo , Corteza Prefrontal/efectos de los fármacos , Corteza Prefrontal/metabolismo , Ratas , Serotonina/metabolismo , Estrés Psicológico/metabolismoRESUMEN
Delta-sleep-inducing peptide (DSIP) is an endogenous substance that regulates the response of the organism to stress. It was found that DSIP, like diazepam and ethanol, activates muscimol-stimulated 36Cl- uptake in the rat brain cortex and partially counteracts the stimulatory action of ethanol on this process. The effect of peptide disappears at the lowering of the incubation temperature. We propose that DSIP is a concordant regulator partly mediating its action through the membrane phospholipids.
Asunto(s)
Corteza Cerebral/efectos de los fármacos , Cloruros/metabolismo , Péptido Inductor del Sueño Delta/farmacología , Etanol/farmacología , Sinaptosomas/efectos de los fármacos , Animales , Transporte Biológico/efectos de los fármacos , Corteza Cerebral/metabolismo , Diazepam/farmacología , Relación Dosis-Respuesta a Droga , Sinergismo Farmacológico , Lípidos de la Membrana/metabolismo , Muscimol/farmacología , Ratas , Receptores de GABA-A/efectos de los fármacos , Receptores de GABA-A/metabolismo , Sinaptosomas/metabolismo , TemperaturaRESUMEN
It was shown, that content of dopamine and its metabolites (DOPAC and HVA) are the same in two groups of rats with different time of immobilization in forced swimming test. One group of low active (LA) animals experienced the immobilization more than 300s, other high active (HA) rats for less than 120 s. Ethanol (2 g/kg per oris) increased the level of DA in the striatum and medial prefrontal cortex only in LA rats and besides, the concentration of dopamine after ethanol administration was higher in the n. accumbens of LA rats, than in that of HA rats. The authors suggest that differences in dopamine content between LA and HA rats are connected with different levels of voluntary alcohol consumption. The opportunity to use both groups of HA and LA rats for developing models of pathogenic heterogeneity of alcoholism is discussed.
