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1.
Phys Rev Lett ; 132(5): 051002, 2024 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-38364164

RESUMO

We present the measurement of the cosmic ray proton spectrum from 50 TeV to 1.3 PeV using 7.81×10^{6} extensive air shower events recorded by the ground-based GRAPES-3 experiment between 1 January 2014 and 26 October 2015 with a live time of 460 day. Our measurements provide an overlap with direct observations by satellite and balloon-based experiments. The electromagnetic and muon components in the shower were measured by a dense array of plastic scintillator detectors and a tracking muon telescope, respectively. The relative composition of the proton primary from the air shower data containing all primary particles was extracted using the multiplicity distribution of muons which is a sensitive observable for mass composition. The observed proton spectrum suggests a spectral hardening at ∼166 TeV and disfavors a single power law description of the spectrum up to the Knee energy (∼3 PeV).

2.
Microbiol Res ; 250: 126808, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34146939

RESUMO

This group has previously reported the role of ascorbic acid (AA) as an antioxidant for survivability and ability to enhancing diazotrophic efficacy in Azotobacter chroococcum Avi2 under hydrogen peroxide (H2O2) stress. However, the present study showed the combined application of AA and Avi2 in drought-susceptible (IR64 and Naveen) and drought-tolerant (Ankit and Satyabhama) rice cultivars to determine their photosynthetic efficacy (chlorophyll fluorescence-imaging), antioxidants, and plant growth-promotion (PGP) under moisture deficit stress (MS, -60 kPa). The results indicated that combined application of AA and Avi2 significantly (p < 0.05) increased the total chlorophyll, relative water content, electrolytic leakage, super oxide dismutase, and catalase activities in all rice cultivars as compared to other MS treatments, whereas stress indicators like proline and H2O2 contents were proportionally increased under MS and their concentration were normalized under combined application of AA and Avi2. Photochemical quenching, non-photochemical quenching, photosynthetic electron transport rate, and the effective quantum efficiency were found to be increased significantly (p < 0.05) in Avi2 + AA as compared to other MS treatments. Moreover, rice roots harbored significantly (p < 0.05) higher copy number of nifH gene in Avi2 + AA treatment followed by Avi2 compared to flooded control and other MS treatments. Combined application of AA and Avi2 also increased the grain yield significantly (p < 0.05) by 7.09 % and 3.92 % in drought-tolerant (Ankit and Satyabhama, respectively) and 31.70 % and 34.19 % in drought-susceptible (IR64 and Naveen, respectively) rice cultivars compared to MS treatment. Overall, the present study indicated that AA along with Avi2 could be an effective formulation to alleviate MS vis à vis enhances PGP traits in rice.


Assuntos
Ácido Ascórbico/farmacologia , Azotobacter/fisiologia , Fixação de Nitrogênio , Oryza/efeitos dos fármacos , Oryza/microbiologia , Fotossíntese/efeitos dos fármacos , Água , Antioxidantes/farmacologia , Clorofila/análise , Clorofila/metabolismo , Endófitos/fisiologia , Oryza/genética , Oryza/crescimento & desenvolvimento , Oxirredução , Folhas de Planta/química , Folhas de Planta/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Estresse Fisiológico/efeitos dos fármacos
3.
Plant Physiol Biochem ; 139: 419-427, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30986643

RESUMO

Oxidative stress generates reactive oxygen species which causes cell damage of living organisms and are normally detoxified by antioxidants. Indirect reports signify the damages caused by reactive oxygen species and neutralized by antioxidant, but the direct evidence to confirm this hypothesis is still unclear. To validate our hypothesis, an attempt was made in a diazotrophic bacterium (Azotobacter chroococcum Avi2) as a biological system, and hydrogen peroxide (H2O2) and ascorbic acid were used as oxidative stress and antioxidant supplement, respectively. Additionally, rice plant-growth attributes by Avi2 was also assessed under H2O2 and ascorbic acid. Results indicated that higher concentration of H2O2 (2.5 mM-4.5 mM) showed the complete mortality of Avi2, whereas one ppm ascorbic acid neutralized the effect of H2O2. Turbidity, colony forming unit, DNA quantity, nifH gene abundance, indole acetic acid and ammonia productions were significantly (p < 0.5) increased by 11.93%, 17.29%, 19.80%, 74.77%, 71.89%, and 42.53%, respectively in Avi2-treated with 1.5 mM H2O2 plus ascorbic acid compared to 1.5 mM H2O2 alone. Superoxide dismutase was significantly (p < 0.5) increased by 60.85%, whereas catalase and ascorbate peroxidase activities were significantly (p < 0.05) decreased by 64.28% and 68.88% in Avi2-treated with 1.5 mM H2O2 plus ascorbic acid compared to 1.5 mM H2O2 alone. Germination percentage of three rice cultivars (FR13a, Naveen and Sahbhagi dhan) were significantly (p < 0.5) increased by 20%, 13.33%, and 4%, respectively in Avi2-treated with 0.6 mM H2O2 plus ascorbic acid compared with uninoculated control. Overall, this study indicated that ascorbic acid formulation neutralizes the H2O2-oxidative stress and enhances the survivability and plant growth-promoting efficacy of A. chroococcum Avi2 and therefore, it may be used as an effective formulation of bio-inoculants in rice under oxidative stress.


Assuntos
Ácido Ascórbico/farmacologia , Azotobacter/fisiologia , Fixação de Nitrogênio/efeitos dos fármacos , Oryza/crescimento & desenvolvimento , Oryza/microbiologia , Antioxidantes , Peróxido de Hidrogênio/farmacologia , Fixação de Nitrogênio/fisiologia , Oryza/metabolismo , Estresse Oxidativo/efeitos dos fármacos
4.
Phys Rev Lett ; 122(10): 105101, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30932668

RESUMO

The GRAPES-3 muon telescope located in Ooty, India records rapid (∼10 min) variations in the muon intensity during major thunderstorms. Out of a total of 184 thunderstorms recorded during the interval of April 2011-December 2014, the one on December 1, 2014 produced a massive potential of 1.3 GV. The electric field measured by four well-separated (up to 6 km) monitors on the ground was used to help estimate some of the properties of this thundercloud, including its altitude and area that were found to be 11.4 km above mean sea level and ≥380 km^{2}, respectively. A charging time of 6 min to reach 1.3 GV implied the delivery of a power of ≥2 GW by this thundercloud that was moving at a speed of ∼60 km h^{-1}. This work possibly provides the first direct evidence for the generation of gigavolt potentials in thunderclouds that could also possibly explain the production of highest-energy (100 MeV) gamma rays in the terrestrial gamma-ray flashes.

5.
Neuroscience ; 232: 139-50, 2013 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-23232259

RESUMO

Previously we showed that 1-(4'-aminophenyl)-4-methyl-7,8-methylene-dioxy-2,3-benzodiazepine (GYKI-52466), an ionotropic AMPA receptor antagonist, can trigger strong, presumably metabotropic, protection against seizures and stroke at very low doses. To date, no study has determined brain and plasma concentrations of GYKI-52466 following subcutaneous administration in animals with or without brain damage. Here we developed and validated a rapid method of high-performance liquid chromatography with diode array detection. Chromatographic separation was achieved by a Luna C18 column using a mixture of 25 mM phosphate buffer (pH 7.0)-methanol-acetonitrile (40:37.5:22.5, v/v/v) as the mobile phase at a flow rate of 1.2 mL/min. The method showed acceptable precision and accuracy and allowed a precise quantification of 25 ng/mL GYKI-52466 in the plasma and brain. Recovery of GYKI-52466 from the plasma and brain was >87%, and GYKI was stable at room temperature and during prolonged storage at -20 °C. The method was successfully applied in measuring levels of GYKI-52466 following administration of 3 and 20 mg/kg of GYKI-52466 in control and brain damaged rats. A low brain concentration of 0.56 µM GYKI-52466 was observed with 3mg/kg compared to 10.7 µM with 20 mg/kg at 90 min post drug administration. Severe ataxia was observed with the 20mg/kg dose for up to 90 min. Furthermore, in ischaemic animals, there was no evidence of a 'surge' in brain GYKI concentrations at the injury site, confirming the integrity of the blood-brain barrier in the region of infarct. Taken together, our findings support a metabotropic mode of action underlying the low-dose neuroprotective efficacy of GYKI-52466.


Assuntos
Benzodiazepinas/farmacocinética , Encéfalo/metabolismo , Cromatografia Líquida de Alta Pressão/métodos , Antagonistas de Aminoácidos Excitatórios/farmacocinética , Hipóxia-Isquemia Encefálica/metabolismo , Fármacos Neuroprotetores/farmacocinética , Animais , Ataxia/tratamento farmacológico , Ataxia/metabolismo , Benzodiazepinas/farmacologia , Encéfalo/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão/instrumentação , Antagonistas de Aminoácidos Excitatórios/farmacologia , Hipóxia-Isquemia Encefálica/tratamento farmacológico , Masculino , Fármacos Neuroprotetores/farmacologia , Distribuição Aleatória , Ratos Sprague-Dawley , Sensibilidade e Especificidade
6.
Neuroscience ; 232: 128-38, 2013 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-23246617

RESUMO

Experimental preconditioning provides beneficial outcomes in conditions such as cardiac surgery, brain surgery and stroke. Here we evaluated the protective effects of low-dose subcutaneous GYKI-52466 preconditioning in a rat model of hypoxic-ischaemic (HI) brain injury. Male Sprague-Dawley rats (postnatal day 26) were administered saline or GYKI-52466 (GYKI; 3-mg/kg, 90 min; 1-mg/kg, twice in 120 min; or 0.5-mg/kg, thrice in 180 min) prior to left common carotid artery occlusion. Animals were allowed to recover for 2h, and then placed in a hypoxia chamber (8% O2/92% N2; 33 ± 1°C) for 1h. A sham surgery group received saline without HI. Seizure activity was scored during hypoxia and sensorimotor tests performed before surgery and at 1, 7, 14 and 90 days post-HI. On days 14 and 90 brains were fixed and sectioned for the assessment of infarct size and ventricular enlargement. Low-dose GYKI-52466 preconditioning significantly reduced infarct volume and ventricular enlargement relative to saline-treated controls at day 14 after HI. On day 90, tissue loss was significantly reduced by GYKI 3-mg/kg compared to saline. Foot-faults, paw use asymmetry, and postural reflex scores were significantly improved in all GYKI treatment groups. Our results show that GYKI-52466 is effective at doses well-below, and at pre-administration intervals well-beyond previous studies, and suggest that a classical blockade of ionotropic AMPA receptors does not underlie its neuroprotective effects. Low-dose GYKI-52466 preconditioning represents a novel, prophylactic strategy for neuroprotection in a field almost devoid of effective pharmaceuticals.


Assuntos
Benzodiazepinas/administração & dosagem , Hipóxia-Isquemia Encefálica/tratamento farmacológico , Fármacos Neuroprotetores/administração & dosagem , Recuperação de Função Fisiológica/efeitos dos fármacos , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Encéfalo/fisiopatologia , Doenças das Artérias Carótidas , Artéria Carótida Primitiva , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Hipóxia-Isquemia Encefálica/patologia , Hipóxia-Isquemia Encefálica/fisiopatologia , Masculino , Atividade Motora/efeitos dos fármacos , Atividade Motora/fisiologia , Postura , Ratos Sprague-Dawley , Recuperação de Função Fisiológica/fisiologia , Reflexo/efeitos dos fármacos , Reflexo/fisiologia , Convulsões/prevenção & controle
8.
Food Chem Toxicol ; 46(7): 2533-9, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18499323

RESUMO

Organochlorines (isomers of hexachlorocyclohexane--HCHs and metabolites of dichlorodiphenyltrichloroethane--DDTs, aldrin and endosulfan) and organophosphate (chlorpyrifos) insecticide residues were investigated by gas liquid chromatography in the blood of fish, chick, goat and man. The plasma levels of testosterone (T) and estradiol-17beta (E2) was measured by radioimmunoassay in the catfish Rita rita captured from unpolluted reference site and polluted river Gomti during prespawning phase. Results indicated that in R. rita the SigmaDDT, SigmaHCH, endosulfan, aldrin, chlorpyrifos in blood levels were in preferential order (SigmaDDT>SigmaHCH>endosulfan>aldrin>chlorpyrifos) of their bioaccumulation. The blood levels of SigmaHCH and SigmaDDT also showed high levels in chick, goat and man, and preferential order of bioaccumulation was goat>chick>man>fish. The SigmaDDT also showed preferential order (man>chick>goat>fish) of bioaccumulation. Among the different tissues of fish (blood, liver, brain and ovary) the SigmaDDT was very high as compared to SigmaHCH as well as the rest of tissues which was very selective bioconcentration in different tissues of fish during prespawning phase. The gonado-somatic index, T and E2 declined in the catfish captured from polluted river when compared with the catfish captured from reference site affecting reproductive physiology. Our results indicated that increase of insecticides in blood level in vertebrates causes reproductive dysfunction and suggested that for human beings food like fish, chick and goat containing beyond permissible limit of insecticides must be avoided.


Assuntos
Peixes-Gato/metabolismo , Galinhas/metabolismo , Contaminação de Alimentos/análise , Cabras/metabolismo , Resíduos de Praguicidas/análise , Reprodução/efeitos dos fármacos , Adulto , Animais , Análise Química do Sangue , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Peixes-Gato/sangue , Peixes-Gato/fisiologia , Galinhas/sangue , Galinhas/fisiologia , Monitoramento Ambiental , Estradiol/sangue , Feminino , Cabras/sangue , Cabras/fisiologia , Humanos , Índia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Especificidade de Órgãos , Ovário/efeitos dos fármacos , Ovário/metabolismo , Resíduos de Praguicidas/farmacocinética , Resíduos de Praguicidas/farmacologia , Reprodução/fisiologia , Especificidade da Espécie , Testosterona/sangue , Distribuição Tecidual
9.
Pediatr Neurosurg ; 42(3): 171-3, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16636620

RESUMO

Associated cranial abnormalities with spinal dysraphism are not uncommon. We came across an unusual case of a 1-year-old male child with spinal dysraphism having lumbar meningomyelocele, who also had split cord malformation (hemicord with intervening bony spur) with lipoma of one of the hemicord and filum terminale. The patient also had communicating hydrocephalus without Chiari malformation and also near-total frontal bone agenesis. Single photon emission computed tomography scanning of brain revealed normal perfusion. In the first stage of repair, the patient had postoperative CSF leak for which ventriculo-peritoneal shunt was performed. This constitutes a rare anomaly associated with spinal dysraphism.


Assuntos
Osso Frontal/anormalidades , Hidrocefalia/cirurgia , Disrafismo Espinal/cirurgia , Osso Frontal/patologia , Osso Frontal/cirurgia , Humanos , Hidrocefalia/diagnóstico , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Lactente , Laminectomia , Lipoma/diagnóstico , Lipoma/cirurgia , Vértebras Lombares/cirurgia , Imageamento por Ressonância Magnética , Masculino , Meningocele/diagnóstico , Meningocele/cirurgia , Meningomielocele/diagnóstico , Meningomielocele/cirurgia , Defeitos do Tubo Neural/diagnóstico , Defeitos do Tubo Neural/cirurgia , Complicações Pós-Operatórias/cirurgia , Reoperação , Sacro/cirurgia , Medula Espinal/patologia , Medula Espinal/cirurgia , Neoplasias da Medula Espinal/diagnóstico , Neoplasias da Medula Espinal/cirurgia , Disrafismo Espinal/diagnóstico , Tomografia Computadorizada de Emissão de Fóton Único , Tomografia Computadorizada por Raios X , Derivação Ventriculoperitoneal
10.
J Pineal Res ; 5(5): 419-26, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-3171888

RESUMO

The present study examines the relationship of the pineal gland to gonadal activity during the annual reproductive cycle in the freshwater catfish Clarias batrachus. The hormonal profiles of testosterone, estradiol-17 beta, estrone, and 17 alpha-hydroxyprogesterone along with the gonadosomatic index (GSI) were monitored to assess the effect of pinealectomy. Pinealectomy appeared to accelerate the gonadal development from January to May. Removal of pineal prior to the start of gonadal recrudescence (January and February), induced initiation of ovarian recrudescence earlier than scheduled in nature. On the other hand pinealectomy during the vitellogenic phase (May to June) reduced the gonadal activity, suggesting the stimulatory role of pineal on gonads. During the remaining period of July to December (postvitellogenic and early resting phase) pinealectomy had no effect on gonadal activity. Thus, in this species the pineal gland during the annual reproductive cycle appears to have either inhibitory, stimulatory, or no effect on gonadal physiology depending upon the sexual conditions.


Assuntos
Peixes-Gato/fisiologia , Estradiol/sangue , Hidroxiprogesteronas/sangue , Glândula Pineal/fisiologia , Reprodução , Testosterona/sangue , 17-alfa-Hidroxiprogesterona , Animais , Estrona/sangue , Feminino , Ovário/fisiologia , Estações do Ano , Vitelogênese
11.
J Pineal Res ; 4(4): 387-94, 1987.
Artigo em Inglês | MEDLINE | ID: mdl-3668789

RESUMO

Thyroxine and triiodothyronine (T3) were measured by radioimmunoassay in serum and thyroid gland of the freshwater teleost Clarias batrachus. Pinealectomy increased the glandular levels of the thyroid hormones but decreased the plasma levels of T4 concomitantly with the increase of T3 levels. Most of the effects of pinealectomy on thyroid hormones were restricted to the gonadal development periods. Pinealectomy has shown no significant impact on thyroid hormones during the other periods of the reproductive cycle. Thus, it appears that the pineal gland is inhibitory to thyroid hormones during gonadal development and maturation.


Assuntos
Peixes-Gato/sangue , Glândula Pineal/fisiologia , Reprodução , Tiroxina/sangue , Tri-Iodotironina/sangue , Animais , Feminino , Radioimunoensaio
12.
J Pineal Res ; 4(4): 377-86, 1987.
Artigo em Inglês | MEDLINE | ID: mdl-3478467

RESUMO

Melatonin and 5-methoxytryptamine have been studied in the freshwater teleost Clarias batrachus during the prespawning period. The data have provided evidence of the inhibitory effects on sex steroids and thyroid hormones when the pineal indoleamines melatonin and 5-methoxytryptamine (5-MT) are administered intramuscularly daily in the afternoon for 27 days. The different dose levels had different effects. The higher dose levels of melatonin showed the initiation of counter inhibitory impacts on testosterone and T3, T4 levels. The melatonin acted more effectively than 5-MT.


Assuntos
5-Metoxitriptamina/farmacologia , Peixes-Gato/sangue , Hormônios Esteroides Gonadais/sangue , Melatonina/farmacologia , Reprodução/efeitos dos fármacos , Hormônios Tireóideos/sangue , Triptaminas/farmacologia , 17-alfa-Hidroxiprogesterona , Animais , Estradiol/sangue , Estrona/sangue , Feminino , Hidroxiprogesteronas/sangue , Masculino , Radioimunoensaio , Testosterona/sangue , Tiroxina/sangue , Tri-Iodotironina/sangue
13.
Urology ; 22(3): 314-7, 1983 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-6623786

RESUMO

We report on a sixty-six-year-old man with a poorly differentiated, diffuse lymphoma in whom bilateral multiple renal masses developed six months after starting chemotherapy. Computerized tomography and selective renal arteriograms were suggestive of either recurrence of lymphoma or renal cell carcinoma. Kidney biopsy revealed renal oncocytomas, benign renal tumors. The patient was spared further courses of cytotoxic therapy.


Assuntos
Adenoma/diagnóstico , Neoplasias Renais/diagnóstico , Linfoma , Neoplasias Primárias Múltiplas/diagnóstico , Adenoma/patologia , Idoso , Biópsia , Humanos , Rim/patologia , Neoplasias Renais/patologia , Masculino
14.
Xenobiotica ; 6(9): 537-52, 1976 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-983124

RESUMO

1. Beagle dogs were chronically treated with cocaine, 5 mg/kg subcutaneously twice daily for 6 weeks, followed by same dose of [3H]cocaine given intravenously. 2. The t1/2 values of cocaine in plasma, liver, spleen and heart, in acutely and chronically treated dogs, were: 1-2, 1-1; 2-2, 1-8; 1-8, 1-3; 2-0, 1-2 h, respectively. In both groups, cocaine disappeared from all areas of the central nervous system 12-24 h after injection but significant amounts of radioactivity due to benzoylnorecgonine and benzoylecgonine persisted in the CNS even 1 week after administration of cocaine. Brain-to-plasma ratios of cocaine were lower in chronically-treated than in acutely-treated dogs 2 and 4 h after injection. 3. Norcocaine, benzoylnorecgonine, benzoylecgonine and ecgonine were metabolites of cocaine in dog brain in both groups. Norcocaine and benzoylnorecgonine were present in higher amounts in brains of chronically treated dogs. Rate of disappearance of norcocaine was similar to cocaine in both groups. 4. The amounts of cocaine excreted in urine and faeces as percentage of dose were 0-9-5-0, 1-1-6 in the acute and 2-2-3-3 and 0-2-0-3 in the chronically treated dogs. Major excretion of radiactivity occurred in urine within 24 h in both groups. Total radioactivity (65% of dose) in urine plus faeces was similar in both groups. 5. Norcocaine, benzoylnorecgonine, benzoylecgonine, ecgonine, norecgonine, ecgonine methyl ester and unidentified compounds were urinary metabolites of cocaine in both groups. Benzoylnorecgonine and ecgonine were excreted in higher amounts and benzoylecgonine and norecgonine in lower amounts in the acute than in the chronically treated dogs. 6. The possible role of persistence of benzoylnorecgonine and benzoylecgonine (which possessed potent stimulant activity intracisternally) in the CNS is discussed.


Assuntos
Cocaína/metabolismo , Animais , Cocaína/sangue , Cocaína/toxicidade , Cães , Fezes/análise , Feminino , Masculino , Especificidade de Órgãos , Fatores de Tempo
15.
J Pharmacol Exp Ther ; 196(3): 556-69, 1976 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-1263111

RESUMO

A sensitive method was developed for the estimation of [3H] cocaine in biological materials. After an injection of 8 mg/kg i.v. in male Wistar rats, peak levels in brain, tissues and plasma occurred within 15 minutes and cocaine disappeared completely from brain and plasma 6 hours postinjection. The T1/2 of cocaine in brain and plasma was 0.4 and 0.3 hour, respectively. No significant differences were observed in the rates of disappearance of cocaine from the subcutaneous site in acute and chronically treated rats after an injection of 20 mg/kg. After a 20 mg/kg s. c. dose, the peak levels of cocaine were attained gradually in 4 hours in brain, tissues and plasma with the exception of heart (0.5 hour) and fat (2 hours). These peak levels shifted from 4 to 2 hours in the chronically treated group. Consistently higher levels of cocaine were found to be sequestered in fat in the chronically treated animals. The T1/2 of cocaine in brain and plasma of chronically treated rats was approximately 1.8 to 2 hours and that in the acutely treated animals, 0.8 to 1 hour. The brain/plasma ratios were also somewhat higher in chronically treated as compared to the acutely treated animals and were indicative of a high affinity of tissue for cocaine. Although cocaine did not persist in brains of acutely treated animals, measurable amounts were shown to persist in brain and other tissues of chronically treated animals long after the disappearance in plasma. Significantly high concentrations of metabolites of cocaine persisted in brain and plasma of acutely and chronically treated animals. No significant differences were observed in the plasma protein binding of cocaine in control, acutely and chronically treated rats. Unchanged cocaine was excreted in very small amounts in rat bile and approximately 36% of the dose (5 mg/kg i. v.) was excreted as metabolites 3.5 hours after injection. Excretion of free cocaine in urine and feces after a 20 mg/kg s. c. dose in acutely and chronically treated rats was 1.2 and 1.5%, respectively. Significantly higher excretion of total radioactivity occurred in feces in the chronic group (35.9%) as compared to the acute group (22.1%). Benzoylecgonine, benzoyl norecgonine, ecgonine methyl ester and ecgonine were identified as urinary metabolites in both acute and chronic animals. In addition, evidence was obtained for the presence of a phenolic metabolite and two other hydroxylated metabolites (with hydroxylation presumably in positions 6 and 7 of the pyrrolidine ring). Implications of these observations with respect to systemic toxicity, the absence of tolerance and physical dependence liability of cocaine are discussed.


Assuntos
Cocaína/metabolismo , Animais , Bile/metabolismo , Biotransformação , Proteínas Sanguíneas/metabolismo , Cocaína/administração & dosagem , Injeções Subcutâneas , Masculino , Ligação Proteica , Ratos , Solubilidade , Fatores de Tempo
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