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1.
J Anim Ecol ; 93(7): 796-811, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38561901

RESUMO

Many populations migrate between two different habitats (e.g. wintering/foraging to breeding area, mainstem-tributary, river-lake, river-ocean, river-side channel) as part of their life history. Detection technologies, such as passive integrated transponder (PIT) antennas or sonic receivers, can be placed at boundaries between habitats (e.g. near the confluence of rivers) to detect migratory movements of marked animals. Often, these detection systems have high detection probabilities and detect many individuals but are limited in their ability to make inferences about abundance because only marked individuals can be detected. Here, we introduce a mark-recapture modelling approach that uses detections from a double-array PIT antenna system to imply movement directionality from arrays and estimate migration timing. Additionally, when combined with physical captures, the model can be used to estimate abundances for both migratory and non-migratory groups and help quantify partial migration. We first test our approach using simulation, and results indicate our approach displayed negligible bias for total abundance (less than ±1%) and slight biases for state-specific abundance estimates (±1%-6%). We fit our model to array detections and physical captures of three native fishes (humpback chub [Gila cypha], flannelmouth sucker [Catostomus latipinnis] and bluehead sucker [Catostomus discobolus]) in the Little Colorado River (LCR) in Grand Canyon, AZ, a system that exhibits partial migration (i.e. includes residents and migrants). Abundance estimates from our model confirm that, for all three species, migratory individuals are much more numerous than residents. There was little difference in movement timing between 2021 (a year without preceding winter/spring floods) and 2022 (a year with a small flood occurring in early April). In both years, flannelmouth sucker arrived in mid-March whereas humpback chub and bluehead sucker arrivals occurred early- to mid-April. With humpback chub and flannelmouth sucker, movement timing was influenced by body size so that large individuals were more likely to arrive early compared to smaller individuals. With more years of data, this model framework could be used to evaluate ecological questions pertaining to flow cues and movement timing or intensity, relative trends in migrants versus residents and ecological drivers of skipped spawning.


Assuntos
Migração Animal , Animais , Modelos Biológicos , Sistemas de Identificação Animal , Densidade Demográfica , Rios , Estações do Ano
2.
Public Health ; 117(3): 187-95, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12825469

RESUMO

The Scottish mental survey of 1932 (SMS1932) recorded mental ability test scores for nearly all children born in 1921 and at school in Scotland on 1 June 1932. The Collaborative and Renfrew/Paisley studies, two of the Midspan studies, obtained health and social data by questionnaire and a physical examination in the 1970s. Some Midspan participants were born in 1921 and may also have taken part in the SMS1932, so there was a possibility that their mental ability data from childhood would be available. The 1921 born Midspan participants were matched with the computerized SMS1932 database, and in total, 1032 of 1251 people (82.5%) were matched successfully. Of those matched, 938 (90.9%) had a mental ability test score recorded. The mean score of the matched sample was 37.2 (standard deviation (SD) 13.9) out of a possible score of 76. The mean (SD) for the boys and girls was 38.3 (14.2) and 35.7 (13.9), respectively. This compared with 38.6 (15.7) and 37.2 (14.3) for boys and girls in all of Scotland. Graded relationships were found between mental ability in childhood, and social class and deprivation category of residence in adulthood. Being in a higher social class or in a more affluent deprivation category was associated with higher childhood mental ability scores, and the scores reduced with increasing deprivation. Future plans for the matched data include examining associations between childhood mental ability and other childhood and adult risk factors for disease in adulthood, and modelling childhood mental ability, alongside other factors available in the Midspan database, as a risk factor for specific illnesses, admission to hospital and mortality.


Assuntos
Previsões/métodos , Nível de Saúde , Testes de Inteligência , Classe Social , Adulto , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Características de Residência , Escócia/epidemiologia , Inquéritos e Questionários
3.
Water Sci Technol ; 46(10): 115-21, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12479460

RESUMO

The paper outlines the effects of polymer conditioning on alum sludge properties, such as floc size, density, fractal dimension (DF) and rheological properties. Experimental results demonstrate that polymer conditioning of alum sludge leads to: larger floc size with a plateau reached in higher doses; higher densities associated with higher doses; increased degree of compactness; and an initial decrease followed by an increase of supernatant viscosity with continued increase in polymer dose. The secondary focus of this paper dwells on a comparison of the estimates of optimum dose using different criteria that emanate from established dewatering tests such as CST, SRF, liquid phase viscosity and modified SRF as well as a simple settlement test in terms of CML30. Alum sludge was derived from a water works treating coloured, low-turbidity raw waters.


Assuntos
Compostos de Alúmen/química , Esgotos/química , Eliminação de Resíduos Líquidos/métodos , Floculação , Polímeros , Água/análise
4.
Appl Occup Environ Hyg ; 16(10): 944-51, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11599543

RESUMO

In epidemiological studies designed to identify potential health risks of exposures to synthetic vitreous fibers, the characterization of airborne fiber dimensions may be essential for assessing mechanisms of fiber toxicity. Toward this end, air sampling was conducted as part of an industry-wide study of workers potentially exposed to airborne fibrous dusts during the manufacture of refractory ceramic fibers (RCF) and RCF products. Analyses of a subset of samples obtained on the sample filter as well as on the conductive sampling cowl were performed using both scanning electron microscopy (SEM) and transmission electron microscopy (TEM) to characterize dimensions of airborne fibers. Comparison was made of bivariate fiber size distributions (length and diameter) from air samples analyzed by SEM and by TEM techniques. Results of the analyses indicate that RCF size distributions include fibers small enough in diameter (< 0.25 microm) to be unresolved by SEM. However, longer fibers (> 60 microm) may go undetected by TEM, as evidenced by the proportion of fibers in this category for TEM and SEM analyses (1% and 5%, respectively). Limitations of the microscopic techniques and differences in fiber-sizing rules for each method are believed to have contributed to the variation among fiber-sizing results. It was concluded from these data that further attempts to characterize RCF exposure in manufacturing and related operations should include analysis by TEM and SEM, since the smallest diameter fibers are not resolved with SEM and the fibers of longer length are not sized by TEM.


Assuntos
Poluentes Ocupacionais do Ar/análise , Cerâmica/análise , Fibras Minerais/análise , Humanos , Microscopia Eletrônica , Saúde Ocupacional
5.
Toxicon ; 38(2): 287-91, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10665808

RESUMO

The toxin, ricin (0.4 microg/microl), was exposed to a range of sodium hypochlorite concentrations. SDS PAGE showed that hypochlorite caused the ricin to smear and decrease in mobility and, ultimately, caused a loss of silver staining. Cytotoxicity assays using dye uptake by Hep2 cells showed that treatment with 3 mM hypochlorite inactivated the ricin. Western blotting and ELISAs showed that binding by polyclonal antibodies raised against native ricin, or partially degraded ricin, diminished as hypochlorite degradation of the ricin increased.


Assuntos
Desinfetantes/farmacologia , Ricina/metabolismo , Hipoclorito de Sódio/farmacologia , Animais , Eletroforese em Gel de Poliacrilamida , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Ricina/imunologia , Ricina/toxicidade
6.
Lancet ; 352(9123): 179-84, 1998 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-9683206

RESUMO

BACKGROUND: Previous studies have reported an increased risk of cancer with calcium-channel blockers in man. Other work in animals suggests that inhibitors of angiotensin-I-converting enzyme (ACE) protect against cancer. We aimed to assess the risk of cancer in hypertensive patients receiving ACE inhibitors or other antihypertensive drugs. METHODS: Our retrospective cohort study was based on the records of 5207 patients who attended the Glasgow Blood Pressure Clinic between Jan 1, 1980, and Dec 31, 1995. The patients' records are linked with the Registrar General Scotland and the West of Scotland Cancer Registry. FINDINGS: Compared with the West of Scotland controls, the relative risks of incident and fatal cancer among the 1559 patients receiving ACE inhibitors were 0.72 (95% CI 0.55-0.92) and 0.65 (0.44-0.93). Among the 3648 patients receiving antihypertensive drugs other than ACE inhibitors (calcium-channel blockers 1416, diuretics 2099, beta-blockers 2681), the corresponding relative risks were 110 (0.97-1.22) and 1.03 (0.87-1.20). The relative risk of cancer was lowest in women on ACE inhibitors: 0.63 (0.41-0.93) for incident cancer; 0.48 (0.23-0.88) for fatal cancer; and 0.37 (0.12-0.87) for female-specific cancers. The reduced relative risk of cancer in patients on ACE inhibitors was greatest with follow-up of longer than 3 years. Calcium-channel blockers, diuretics, and beta-blockers had no apparent effect on risk of cancer. INTERPRETATION: Long-term use of ACE inhibitors may protect against cancer. The status of this finding is more that of hypothesis generation than of hypothesis testing; randomised controlled trials are needed.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Anti-Hipertensivos/uso terapêutico , Hipertensão/tratamento farmacológico , Neoplasias/epidemiologia , Estudos de Coortes , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Neoplasias/prevenção & controle , Sistema de Registros/estatística & dados numéricos , Estudos Retrospectivos , Fatores de Risco , Escócia/epidemiologia , Fatores de Tempo
7.
J Epidemiol Community Health ; 52(3): 153-60, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9616419

RESUMO

STUDY OBJECTIVES: In the UK, studies of socioeconomic differentials in mortality have generally relied upon occupational social class as the index of socioeconomic position, while in the US, measures based upon education have been widely used. These two measures have different characteristics; for example, social class can change throughout adult life, while education is unlikely to alter after early adulthood. Therefore different interpretations can be given to the mortality differentials that are seen. The objective of this analysis is to demonstrate the profile of mortality differentials, and the factors underlying these differentials, which are associated with the two socioeconomic measures. DESIGN: Prospective observational study. SETTING: 27 work places in the west of Scotland. PARTICIPANTS: 5749 men aged 35-64 who completed questionnaires and were examined between 1970 and 1973. FINDINGS: At baseline, similar gradients between socioeconomic position and blood pressure, height, lung function, and smoking behaviour were seen, regardless of whether the education or social class measure was used. Manual social class and early termination of full time education were associated with higher blood pressure, shorter height, poorer lung function, and a higher prevalence of smoking. Within education strata, the graded association between smoking and social class remains strong, whereas within social class groups the relation between education and smoking is attenuated. Over 21 years of follow up, 1639 of the men died. Mortality from all causes and from three broad cause of death groups (cardiovascular disease, malignant disease, and other causes) showed similar associations with social class and education. For all cause of death groups, men in manual social classes and men who terminated full time education at an early age had higher death rates. Cardiovascular disease was the cause of death group most strongly associated with education, while the non-cardiovascular non-cancer category was the cause of death group most strongly associated with adulthood social class. The graded association between social class and all cause mortality remains strong and significant within education strata, whereas within social class strata the relation between education and mortality is less clear. CONCLUSIONS: As a single indicator of socioeconomic position occupational social class in adulthood is a better discriminator of socioeconomic differentials in mortality and smoking behaviour than is education. This argues against interpretations that see cultural--rather than material--resources as being the key determinants of socioeconomic differentials in health. The stronger association of education with death from cardiovascular causes than with other causes of death may reflect the function of education as an index of socioeconomic circumstances in early life, which appear to have a particular influence on the risk of cardiovascular disease.


Assuntos
Escolaridade , Nível de Saúde , Mortalidade , Classe Social , Adulto , Doenças Cardiovasculares/mortalidade , Seguimentos , Volume Expiratório Forçado , Humanos , Pneumopatias/mortalidade , Masculino , Pessoa de Meia-Idade , Neoplasias/mortalidade , Prevalência , Modelos de Riscos Proporcionais , Estudos Prospectivos , Fatores de Risco , Escócia/epidemiologia , Fumar/mortalidade
8.
J Hypertens ; 16(1): 119-24, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9533425

RESUMO

OBJECTIVE: To measure rates of incident and fatal cancer in hypertensive patients taking calcium antagonists and to compare these with rates in three control groups. DESIGN: A retrospective analysis of cancer in patients of the Glasgow Blood Pressure Clinic prescribed either a calcium antagonist or other antihypertensive drugs (non-calcium antagonist group). Record linkage of the clinic with the West of Scotland Cancer Registry and with the Registrar General, Scotland provided information on incidence of cancer and on deaths and their causes. PATIENTS: 2297 patients were prescribed calcium antagonist and 2910 were prescribed antihypertensive drugs other than calcium antagonist. MAIN OUTCOME MEASURES: Relative risk of cancer, the ratio of observed to expected cancers in the calcium antagonist group, was estimated using expected values based on three control groups; namely the non-calcium antagonist group, a middle-aged population of Renfrew and Paisley and the West of Scotland population. RESULTS: There were 134 incident cancers in the calcium antagonist group, representing relative risks of 1.02 [95% confidence interval (CI) 0.82-1.271 compared with the non-calcium antagonist group, 1.01 (95% CI 0.84-1.18) compared with Renfrew-Paisley controls and 1.02 (95% CI 0.85-1.19) compared with West of Scotland controls. Findings for cancer mortality were similarly negative. Risks were no higher for older patients. CONCLUSIONS: Our study lends no support to the suggestion that calcium antagonists cause cancer.


Assuntos
Anti-Hipertensivos/efeitos adversos , Bloqueadores dos Canais de Cálcio/efeitos adversos , Neoplasias/induzido quimicamente , Neoplasias/epidemiologia , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Hipertensão/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Neoplasias/mortalidade , Sistema de Registros , Estudos Retrospectivos , Fatores de Risco , Escócia/epidemiologia
9.
Pediatr Dermatol ; 9(3): 231-8, 1992 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1488371

RESUMO

In dystrophic epidermolysis bullosa (EB), a combination of diminished food intake and increased nutritional requirements commonly leads to malnourishment. Adequate nutrition in these patients could provide many benefits, including improved growth, accelerated healing, decreased susceptibility to infection, and enhanced well-being. We assessed nutrition status of children with dystrophic EB, and evaluated the benefits of nutritional advice in those who were considered malnourished. The majority of patients had inadequate intakes of a wide spectrum of nutrients, including those who appeared to be relatively mildly affected. We were unable to secure persisting substantial improvements in dietary intake despite thorough counseling. Adequate nutrition in patients with dystrophic EB depends on active nutritional support starting from birth. The need for more invasive techniques of nourishment, such as nasogastric and gastrostomy feeding, may have to be considered earlier than is currently the case.


Assuntos
Transtornos da Nutrição Infantil/etiologia , Epidermólise Bolhosa Distrófica/complicações , Estatura , Peso Corporal , Criança , Transtornos da Nutrição Infantil/sangue , Transtornos da Nutrição Infantil/tratamento farmacológico , Pré-Escolar , Ingestão de Energia , Epidermólise Bolhosa Distrófica/sangue , Epidermólise Bolhosa Distrófica/tratamento farmacológico , Feminino , Humanos , Lactente , Ferro/sangue , Ferro/uso terapêutico , Masculino , Necessidades Nutricionais , Vitaminas/uso terapêutico , Zinco/sangue , Zinco/uso terapêutico
11.
Mamm Genome ; 1(1): 53-6, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1724400

RESUMO

A human hair cuticle ultrahigh-sulphur keratin Q (UHSK) gene (KRN1) has been mapped by Southern analysis of a somatic cell hybrid panel and by in situ hybridization. A probe containing the coding region of this gene mapped to 11pter- greater than 11q21 using the hybrid cell panel and on in situ hybridization mapped to two regions on chromosome 11: the distal part of 11p15, most likely 11p15.5, and the distal part of 11q13, most likely 11q13.5. A probe from the 3' noncoding region of KRN1 mapped to 11q13.5 indicating that this was the map location of the cloned gene. The sequence of 11p15.5 is termed KRN1-like (KRN1L). The results reveal that the cuticle UHSK gene family is clustered in the human genome.


Assuntos
Cromossomos Humanos Par 11 , Cabelo/química , Queratinas/genética , Southern Blotting , Mapeamento Cromossômico , Humanos , Hibridização de Ácido Nucleico
12.
J Cell Biol ; 111(6 Pt 1): 2587-600, 1990 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1703541

RESUMO

The major histological components of the hair follicle are the hair cortex and cuticle. The hair cuticle cells encase and protect the cortex and undergo a different developmental program to that of the cortex. We report the molecular characterization of a set of evolutionarily conserved hair genes which are transcribed in the hair cuticle late in follicle development. Two genes were isolated and characterized, one expressed in the human follicle and one in the sheep follicle. Each gene encodes a small protein of 16 kD, containing greater than 50 cysteine residues, ranging from 31 to 36 mol% cysteine. Their high cysteine content and in vitro expression data identify them as ultra-high-sulfur (UHS) keratin proteins. The predicted proteins are composed almost entirely of cysteine-rich and glycine-rich repeats. Genomic blots reveal that the UHS keratin proteins are encoded by related multigene families in both the human and sheep genomes. Tissue in situ hybridization demonstrates that the expression of both genes is localized to the hair fiber cuticle and occurs at a late stage in fiber morphogenesis.


Assuntos
Cisteína , Genes , Cabelo/metabolismo , Proteínas/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Diferenciação Celular , Clonagem Molecular , DNA/genética , DNA/isolamento & purificação , Biblioteca Genômica , Cabelo/citologia , Cabelo/ultraestrutura , Humanos , Queratinas/genética , Dados de Sequência Molecular , Peso Molecular , Hibridização de Ácido Nucleico , Biossíntese de Proteínas , Proteínas/isolamento & purificação , Sequências Repetitivas de Ácido Nucleico , Mapeamento por Restrição , Homologia de Sequência do Ácido Nucleico , Ovinos , Transcrição Gênica
13.
Cell ; 63(1): 119-32, 1990 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-2208276

RESUMO

We have analyzed the DNA sequences associated with four different human telomeres. Two are members of distinct repeated sequence families which are located mainly but not exclusively at telomeres. Two are unique in the genome, one deriving from the long arm telomere of chromosome 7 and the other from the pseudoautosomal telomere. One telomere-associated repeated sequence has a polymorphic distribution among the chromosome ends, being present at a different combination of ends in different individuals. These data thus identify a new source of human genetic variation and indicate that the canonical features of the organization of telomere-associated DNA are widely conserved in evolution.


Assuntos
Cromossomos Humanos/ultraestrutura , DNA/genética , Polimorfismo Genético , Animais , Sequência de Bases , Linhagem Celular , Mapeamento Cromossômico , Clonagem Molecular , Humanos , Células Híbridas/citologia , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Mapeamento por Restrição
14.
J Cell Sci ; 95 ( Pt 4): 521-6, 1990 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-2200795

RESUMO

Although eucaryotic chromosomes vary in size over five orders of magnitude and are constituents of diverse genetic systems the fundamental features of their telomeres appear to be almost completely conserved. This can be exploited to enable molecular cloning of human telomeres in yeast and suggests that many of the ideas that will arise from studies of telomeres in the experimentally tractable ciliates and yeasts will hold true of mammalian telomeres. The particular value of cloned mammalian telomeres is that they contribute reagents for mapping mammalian chromosomes and that they provide one set of elements for the construction of artificial mammalian chromosomes.


Assuntos
Cromossomos/ultraestrutura , Clonagem Molecular , Mamíferos/genética , Animais , Sequência de Bases , Evolução Biológica , DNA , Proteínas de Ligação a DNA , Humanos , Dados de Sequência Molecular
16.
J Endocrinol ; 109(1): 45-51, 1986 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-3701243

RESUMO

In the mediobasal hypothalamus (MBH) of pro-oestrous rats or acutely ovariectomized oestrogen-treated adults a marked but short-lived increase in adrenergic activity occurs at 16.00 h, 2 h before the oestrogen-dependent surge of gonadotrophins at 18.00 h. In this study oestrogen-stimulated (noon on day 1) 22-day-old female rats were used which are known to produce surge levels of prolactin at 18.00 h on day 2 and surges of both prolactin and LH at 18.00 h on day 3; although similar treatment of 18-day-old animals or oil-treated 22-day-old rats failed to produce these effects. Radioenzymatic assays of adrenaline concentrations and of the activity of its synthesizing enzyme (phenylethanolamine-N-methyl transferase; PNMT, EC 2.1.1.28) in the MBH of oestrogen-treated 22-day-old rats showed significant (P less than 0.05-0.01) increases in both parameters at 16.00 h (i.e. 2 h before surge levels of gonadotrophins) on days 2 and 3 when compared with other times of day. Such effects were not seen in oil-treated 22-day-old animals or in oestrogen-treated 16-day-old rats. Noradrenaline and dopamine concentrations in the MBH of oestrogen-treated 22-day-old rats remained at baseline levels on days 2 and 3 with the exception of noradrenaline at 17.00 h on day 3 when levels appeared higher (P less than 0.05) than at either 15.00 or 16.00 h.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Catecolaminas/metabolismo , Estradiol/farmacologia , Gonadotropinas Hipofisárias/metabolismo , Hipotálamo Médio/metabolismo , Animais , Epinefrina/metabolismo , Feminino , Hipotálamo Médio/efeitos dos fármacos , Hipotálamo Médio/enzimologia , Hormônio Luteinizante/metabolismo , Ovariectomia , Feniletanolamina N-Metiltransferase/metabolismo , Prolactina/metabolismo , Ratos , Ratos Endogâmicos
17.
Neuroendocrinology ; 41(5): 432-6, 1985 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-3903538

RESUMO

Groups of 4-day cyclic rats were injected (i.p.) with LY 134046 (50 mg/kg), a central inhibitor of phenylethanolamine N-methyltransferase, or saline at 09.00, 13.00 and 19.00 h on the day of proestrus. The incidence of ovulation was examined the following estrous morning. There was no difference in the number of ova in drug-treated animals compared to saline-treated controls. In other groups of 4-day cyclic rats, LY 134046 or saline was injected daily at 10.00 h for 5 consecutive days from proestrus to proestrus inclusive. The animals were decapitated the following day and ova were counted. Epinephrine concentrations were determined by radioenzymatic assay in the mediobasal hypothalamus (MBH) and the medial preoptic area (MPOA). All saline-treated controls and 10/14 of the drug-treated animals had ovulated, while epinephrine concentrations in the MBH and MPOA had been reduced by 95.8 and 94.7%, respectively, compared to saline-treated controls. These experiments suggest that a significant surge of luteinizing hormone occurs to initiate ovulation even after a severe reduction in central epinephrine concentration has taken place.


Assuntos
Benzazepinas/farmacologia , Epinefrina/análise , Hipotálamo/análise , Ovulação/efeitos dos fármacos , Feniletanolamina N-Metiltransferase/antagonistas & inibidores , Animais , Feminino , Hormônio Liberador de Gonadotropina/metabolismo , Sistema Hipotálamo-Hipofisário/fisiologia , Hipotálamo Médio/análise , Área Pré-Óptica/análise , Ratos , Ratos Endogâmicos
18.
Endocrinology ; 116(2): 542-6, 1985 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-4038483

RESUMO

Although evidence has shown that central epinephrine (E) neurons play an essential role in the control of preovulatory gonadotropoin surge in rats, their function and site(s) of action are unknown. These experiments were performed in an attempt to identify any changes in E concentration or activity that might take place in areas of the brain known to receive adrenergic axon terminals and to be associated with increased output of gonadotropins (LH, FSH, and PRL) during the estrous cycle. E concentrations were measured by radioenzymatic assay, and E activity was assessed by the linear rate of decline of E (RDE) which occurs 2 h after administration of the centrally active E synthesis inhibitor, SKF 64139. During the proestrous critical period (1500-1700 h), significant increases in both concentration and RDE occurred in the medial preoptic area (mPOA) accompanied by a smaller but significant increase in the RDE in the mediobasal hypothalamus (MBH); 4 h later (2100-2300 h), significant increases in both concentration and RDE were seen in the MBH. At estrus, although E concentrations were generally higher in both the mPOA and MBH than on other days of the cycle, the concentration and RDE in the MBH increased significantly between 1500-1700 h, while RDE in the mPOA increased again between 1700-1900 h. There were no significant changes in either E concentration or RDE in the mPOA or MBH at metestrus or diestrus or in the perifornical area at any of the times studied. Thus, these findings may be associated with the output of gonadotropins over the periovulatory period.


Assuntos
Epinefrina/fisiologia , Estro , Hipotálamo Médio/fisiologia , Neurônios/fisiologia , Área Pré-Óptica/fisiologia , Animais , Epinefrina/metabolismo , Feminino , Cinética , Gravidez , Ratos , Ratos Endogâmicos , Fatores de Tempo , Distribuição Tecidual
19.
J Endocrinol ; 104(1): 129-35, 1985 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-4038507

RESUMO

The presence of adrenaline within the central nervous system appears to be essential for the occurrence of an oestrogen-stimulated surge of LH in both pro-oestrous and ovariectomized rats. Previous measurements of adrenergic activity based on the rate of decline of adrenaline (RDA) 2 h after injection of a synthesis inhibitor (SKF 64139) suggested that adrenergic activity increases in both the medial preoptic area (MPOA) and the mediobasal hypothalamus (MBH) at the start of the LH surge (15.00-17.00 h). The purpose of the present studies was to see whether oestrogen and progesterone affected this increase in adrenergic activity at the sites of the cell bodies (MPOA) and axon terminals (MBH) of the gonadotrophin-releasing hormone-synthesizing neurone. Rats ovariectomized at dioestrus showed a reduction in both plasma LH concentrations and RDA (P less than 0.01) in the MBH between 15.00 and 17.00 h on the day of expected pro-oestrus. Oestrogen replacement at operation restored LH levels and the RDA to values found in intact rats. Injection of an antioestrogen (Cl-628), with or without oestrogen, also reduced plasma LH levels and the RDA (P less than 0.01) in the MBH. Removal or replacement of oestrogen apparently had little effect on the RDA in the MPOA. In ovariectomized oestrogen-primed rats an injection of progesterone on the morning of expected pro-oestrus advanced and enhanced not only the LH surge but also the RDA in the MBH (P less than 0.001). Moreover, concentrations of adrenaline in the MBH (but not the MPOA) decreased (P less than 0.001) consistently over a 2-h period following injection of progesterone.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Epinefrina/metabolismo , Estradiol/farmacologia , Hipotálamo Médio/metabolismo , Área Pré-Óptica/metabolismo , Progesterona/farmacologia , Animais , Castração , Antagonistas de Estrogênios/farmacologia , Feminino , Hormônio Luteinizante/sangue , Gravidez , Proestro , Ratos , Ratos Endogâmicos , Estilbenos/farmacologia
20.
Brain Res ; 323(2): 326-9, 1984 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-6525520

RESUMO

Previous work has shown a relatively high turnover of adrenaline in the mediobasal hypothalamus during the critical period (15.00-17.00 h) of the proestrous rat. We now report that this high level of adrenergic activity can be detected in the median eminence (turnover rate 1.62 +/- 0.36 pg/micrograms protein/h) rather than the arcuate nucleus (turnover rate 0.18 +/- 0.32 pg/micrograms protein/h). In addition the median eminence was isolated as medial and lateral components and determination of catecholamine concentrations revealed a greater proportion of adrenaline (A) (59%) in the lateral median eminence whereas a larger proportion of dopamine (60%) was found in medial median eminence.


Assuntos
Núcleo Arqueado do Hipotálamo/metabolismo , Epinefrina/metabolismo , Eminência Mediana/metabolismo , Animais , Núcleo Arqueado do Hipotálamo/análise , Dopamina/análise , Epinefrina/análise , Feminino , Gonadotropinas Hipofisárias/metabolismo , Eminência Mediana/análise , Norepinefrina/análise , Ratos , Ratos Endogâmicos
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