RESUMO
Information on the relationship between autonomic functions and malnutrition in children is scant. In the present study, autonomic function tests were conducted in 30 normal subjects and 30 malnourished children aged between 5 and 10 years. The tests performed included tests for parasympathetic functions (resting heart rate, standing-to-lying ratio, lying-to-standing ratio and Valsalva ratio) and tests to assess sympathetic function (hand grip test, galvanic skin resistance). The malnourished children had significantly lower mean weights-for-age (-2.6 Z vs -1.5 Z; p = 0.001), heights-for-age (-2.5 Z vs -1.5 Z; p = 0.001) and weights-for-height (-1.6 Z vs -0.8 Z; p = 0.001). Parasympathetic function tests evaluated were significantly affected in malnourished children. Resting heart rate was significantly higher in the malnourished group (90.6 vs 82.5/min; p = 0.001). The other parasympathetic function tests had significantly lower mean values than in the control group, namely, standing-to-lying ratio (1.25 vs 1.32; p = 0.026), lying-to-standing ratio (1.23 vs 1.29; p = 0.021) and Valsalva ratio (1.26 vs 1.28; p = 0.037). Of the sympathetic function tests conducted, there were no differences between the two groups for hand grip test but galvanic skin resistance was significantly higher in the malnourished subjects (190.1 vs 149.73; p = 0.001). It is concluded that autonomic nervous system function is significantly compromised in malnourished children.
Assuntos
Sistema Nervoso Autônomo/fisiologia , Distúrbios Nutricionais/fisiopatologia , Sistema Nervoso Autônomo/fisiopatologia , Pressão Sanguínea , Criança , Pré-Escolar , Resposta Galvânica da Pele , Força da Mão , Frequência Cardíaca , Humanos , Sistema Nervoso Parassimpático/fisiologia , Valores de ReferênciaRESUMO
Stress is known to produce analgesia. The pain threshold is altered in diabetes. We studied the effect of 1 hr of immobilisation stress on pain threshold in male Wistar rats. The same effect was tested in streptozotocin induced diabetic rats. The pain threshold of tail flick, vocalisation and vocalisation after discharge increased in the control group after the stress procedure. Significant analgesia was also obtained in diabetic rats, for flick and after discharge pain threshold. However the vocalisation threshold was not altered, probably due to the antagonistic action of glucose on opiate receptor at the level of brain stem.
Assuntos
Analgesia , Diabetes Mellitus Experimental/fisiopatologia , Imobilização , Limiar da Dor , Estresse Fisiológico/fisiopatologia , Animais , Glicemia/metabolismo , Tronco Encefálico/metabolismo , Diabetes Mellitus Experimental/induzido quimicamente , Masculino , Antagonistas de Entorpecentes , Ratos , Ratos Wistar , Estreptozocina , Estresse Fisiológico/complicações , Vocalização AnimalRESUMO
There are controversial reports on the effect of diabetes on the pain threshold. We used male Wistar rats to see the effect of streptozotocin induced diabetes on the tail flick, vocalisation and vocalisation after discharge responses. These represent the spinal, lower brain stem and hypothalamic responses respectively. The effect of morphine in these parameters was studied for both the control and diabetic group. In diabetic rats, the pain threshold was increased. However, this increase was not significant. Morphine produced significant analgesia after thirty minutes for tail flick and vocalisation responses and after fifteen minutes for after discharge in the control group. The antinociceptive effect of morphine was delayed and reduced for all three pain threshold confirming the antagonistic action of glucose on opiate receptors.
Assuntos
Analgésicos Opioides/farmacologia , Diabetes Mellitus Experimental/fisiopatologia , Morfina/farmacologia , Dor , Animais , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/metabolismo , Masculino , Naloxona/farmacologia , Antagonistas de Entorpecentes/farmacologia , Medição da Dor , Ratos , Ratos Wistar , Receptores Opioides delta/antagonistas & inibidores , Receptores Opioides delta/metabolismo , EstreptozocinaRESUMO
The present study was designed to investigate the role of central adrenoceptors in the hypotensive effect of intracerebroventricular (ICV) injection of norepinephrine (NE) in conscious rabbits. Experiments were carried out on 19 adult rabbits (oryctolagus cuniculus) of either sex. A dose-dependent hypotensive response to ICV injection of NE was observed with no significant change in heart rate. The hypotensive response of NE was blocked 74.2 +/- 0.7% by yohimbine (alpha-2 adrenergic blocker), and 25.0 +/- 0.5% by metoprolol (beta-1 adrenergic blocker). NE response was not affected either by prazosin or butoxamine (alpha-1 and beta-2 adrenergic blockers respectively). The results suggest that the dose-dependent hypotensive response of ICV administered NE is mediated through alpha-2 and beta-1 central adrenoceptors.
Assuntos
Agonistas alfa-Adrenérgicos/farmacologia , Antagonistas Adrenérgicos alfa/farmacologia , Antagonistas Adrenérgicos beta/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Norepinefrina/antagonistas & inibidores , Norepinefrina/farmacologia , Agonistas alfa-Adrenérgicos/administração & dosagem , Antagonistas Adrenérgicos alfa/administração & dosagem , Antagonistas Adrenérgicos beta/administração & dosagem , Animais , Butoxamina/administração & dosagem , Butoxamina/farmacologia , Relação Dose-Resposta a Droga , Feminino , Frequência Cardíaca/efeitos dos fármacos , Injeções Intravenosas , Injeções Intraventriculares , Masculino , Metoprolol/administração & dosagem , Metoprolol/farmacologia , Norepinefrina/administração & dosagem , Prazosina/administração & dosagem , Prazosina/farmacologia , Coelhos , Ioimbina/administração & dosagem , Ioimbina/farmacologiaRESUMO
The mode and nature of the binding of chlorpromazine (CPZ), a psychotropic drug, with myoglobin, a monomeric muscle protein, were studied spectrofluorometrically and the results compared with those from the binding of CPZ to hemoglobin, a tetrameric allosteric protein from red blood cells (RBC). CPZ interacted with myoglobin in a non-cooperative mode, with a binding constant of 8.4 x 10(3) M-1 in 0.145 M NaCl, pH 6.8, whereas in the case of hemoglobin this interaction was found to be positively cooperative with a binding constant of 4.2 x 10(3) M-1. The interaction of CPZ with myoglobin was not influenced by the NaCl molarity of the solution, whereas CPZ interaction with hemoglobin significantly decreased with increasing NaCl molarity, indicating that CPZ-hemoglobin binding is mostly electrostatic in nature, whereas that of the CPZ-myoglobin complex is of a non-electrostatic type. Thermodynamic analysis revealed that binding of CPZ to hemoglobin was exothermic (delta H degrees = -2.65 kcal/mol), whereas binding to myoglobin was endothermic (delta H degrees = + 1.39 kcal/mol) with a high entropic contribution (delta S degrees = +23 cal/degree/mol), suggesting that CPZ binding to myoglobin is hydrophobic in nature. Such contrasting binding features of this drug have been discussed in the light of a typical subunit interaction property present and absent in hemoglobin and myoglobin, respectively.
Assuntos
Clorpromazina/química , Hemoglobinas/química , Mioglobina/química , Cloreto de Sódio , Espectrometria de Fluorescência , TermodinâmicaRESUMO
Effect of different doses (2.5 mg, 5 mg, 10 mg and 40 mg/kg), s.c., for 2 weeks, of cyproheptadine (CYP) on brain cholesterol and phospholipid of albino rats was investigated. Cyp. 2.5 mg/kg, showed increase in brain cholesterol and phospholipid contents whereas other doses caused a decrease in phospholipid level.
Assuntos
Encéfalo/efeitos dos fármacos , Colesterol/metabolismo , Ciproeptadina/farmacologia , Fosfolipídeos/metabolismo , Animais , Encéfalo/metabolismo , Ciproeptadina/administração & dosagem , Injeções Subcutâneas , Tamanho do Órgão , RatosRESUMO
Autonomic functions were studied in female healthy human subjects during the pre-menstrual, menstrual and post-menstrual phases. Our findings indicate a higher BP (systolic) and lower GSR in pre-menstrual phase as compared to other phases. Parasympathetic activity on the other hand does not show significant differences.
Assuntos
Sistema Nervoso Autônomo/fisiologia , Ciclo Menstrual/fisiologia , Adolescente , Adulto , Pressão Sanguínea/fisiologia , Eletrocardiografia , Feminino , Resposta Galvânica da Pele/fisiologia , Hormônios/fisiologia , Humanos , Pulso Arterial/fisiologiaRESUMO
The prevalence of exercise-induced asthma (EIA) after six minutes of standard exercise test on bicycle ergometer was studied in thirty healthy first degree relations of asthmatic subjects (group II) and was compared with that in thirty healthy controls (group I). Pulmonary function tests (PFT) measuring FVC, FEV1, FEF25-75% and PEFR were performed on each subject prior of exercise, immediately following exercise period and serially at 5 minute interval for 25 minutes thereafter. Bronchial lability was noted in 7% and 27% of the subjects in groups I and II respectively. Of all the parameters measured, FEF25-75% exhibited most striking changes when expressed as % of the baseline value.
Assuntos
Asma Induzida por Exercício/fisiopatologia , Exercício Físico/fisiologia , Pulmão/fisiologia , Adolescente , Adulto , Asma Induzida por Exercício/genética , Feminino , Humanos , Masculino , Testes de Função RespiratóriaRESUMO
Norepinephrine (NE) and its blockers (alpha-1, alpha-2, beta-1 and beta-2) were micro-injected into the anterior hypothalamus of male albino rats and the effects of these injections on rectal temperature were recorded. The results indicated that the thermoregulatory effects of NE were dependent on ambient temperature. The present study further demonstrated the specific involvement of beta-2 receptors present in the anterior hypothalamus concerned with thermoregulation.
Assuntos
Regulação da Temperatura Corporal/fisiologia , Receptores Adrenérgicos/fisiologia , Animais , Regulação da Temperatura Corporal/efeitos dos fármacos , Hipotálamo/efeitos dos fármacos , Hipotálamo/fisiologia , Masculino , Norepinefrina/farmacologia , Ratos , Receptores Adrenérgicos/efeitos dos fármacos , Simpatolíticos/farmacologiaRESUMO
The effect of cyproheptadine (CPH) on glucose tolerance, serum immunoreactive insulin (IRI) and structure of pancreatic islets in albino rats has been studied. Hyperglycemia with glucose intolerance was observed after 10 days of administration of CPH (40 mg/kg, ip). There was insignificant change of fasting IRI after the treatment. Histological studies indicated degranulation and vacuolation of beta cells with enlargement of capillaries. Improvement in blood glucose, glucose tolerance and structure of islets with proliferation of small pancreatic ducts and cell cords were observed 10 days after the withdrawal of CPH.
Assuntos
Ciproeptadina/farmacologia , Insulina/sangue , Ilhotas Pancreáticas/efeitos dos fármacos , Animais , Glicemia/análise , Ciproeptadina/toxicidade , Grânulos Citoplasmáticos/efeitos dos fármacos , Teste de Tolerância a Glucose , Hiperglicemia/induzido quimicamente , Ilhotas Pancreáticas/metabolismo , Ilhotas Pancreáticas/ultraestrutura , Masculino , Ratos , Ratos EndogâmicosRESUMO
The effect of intracerebroventricular (icv) injection of noradrenaline (NA) on the blood pressure was studied in anaesthetised rabbits. Adrenoceptor blockers were used to study the specific adrenoceptor mediating the response. The results indicated a hypotensive response to icv injection of NA. This hypotensive response to NA was blocked by alpha-2 (yohimbine) and beta-1 (metoprolol) but not by alpha-1 (prazosin) and beta-2 (butoxamine) adrenoceptor blockers.
Assuntos
Pressão Sanguínea/fisiologia , Receptores Adrenérgicos/fisiologia , Antagonistas Adrenérgicos alfa/farmacologia , Antagonistas Adrenérgicos beta/farmacologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Norepinefrina/farmacologia , Coelhos , Receptores Adrenérgicos/efeitos dos fármacosRESUMO
Effects of intrahypothalamic and intraventricular microinjections of norepinephrine (NE) were studied in fasted albino rats. Applications of NE into ventromedial hypothalamus (VMH), medial part of lateral hypothalamus (LH) and lateral ventricle (LV) caused marked but short lasting decrease in food intake, whereas lateral part of LH was insensitive to NE administration. Decrease in water intake seemed secondary to decrease in food intake. Decrease in food intake could not be attributed to the alteration of body temperature. This study explains the mechanism of anorexigenic action of amphetamine and the mechanism of hyperphagia following destruction of the ventral noradrenergic bundle.
Assuntos
Comportamento Alimentar/fisiologia , Hipotálamo/efeitos dos fármacos , Norepinefrina/farmacologia , Animais , Temperatura Corporal/efeitos dos fármacos , Comportamento de Ingestão de Líquido/fisiologia , Hipotálamo/fisiologia , Hipotálamo Médio , Injeções Intraventriculares , Masculino , Microinjeções , Norepinefrina/administração & dosagem , Ratos , Ratos EndogâmicosRESUMO
Experiments were carried out in albino rats to find out the effect of propranolol, priscol and atropine on post-hemorrhagic erythropoiesis. Administration of either propranolol or priscol decreased reticulocyte response following hemorrhage, whereas administration of atropine produced no change. The results indicate that alpha as well as beta adrenergic systems participate in the control of erythropoiesis following hemorrhage, whereas parasympathetic system does not take part.
Assuntos
Atropina/farmacologia , Eritropoese/efeitos dos fármacos , Propranolol/farmacologia , Tolazolina/farmacologia , Animais , Feminino , MasculinoRESUMO
The values of Standardized Distal Motor Latency (SDML) of Median, Ulnar and Common Peroneal nerves and the peak to peak amplitude of Evoked Muscle Action Potentials (EMAP) of the small muscles of the limbs were studied in 50 normal subjects. The SDML values showed significant sex difference, whereas no sex difference was observed in the amplitude of the EMAPs.
Assuntos
Músculos/fisiologia , Potenciais de Ação , Adolescente , Adulto , Braço , Feminino , Humanos , Perna (Membro) , Masculino , Valores de Referência , Caracteres SexuaisAssuntos
Distúrbios Nutricionais/fisiopatologia , Periodicidade , Supinação , Adolescente , Adulto , Criança , Pré-Escolar , Eletrocardiografia , Feminino , Frequência Cardíaca , Humanos , MasculinoRESUMO
Effect of change in body posture on cardiac electrical axis has not been well documented. Hence the present work was undertaken to study the effect of passive head-up and head-down postures on ventricular QRS axis and heart rate of anesthetised mice. During head-up posture, there was a statistically significant (P less than 0.02) increase in heart rate whereas during head-down posture, the heart rate decreased insignificantly. These changes in heart rate can be explained on the basis of synus and aortic nerve mediated baroreceptor reflexes. Ventricular QRS axis showed a significant increase (P less than 0.02) during head-up posture and an insignificant decrease during head-down posture. A change in the posture is likely to produce a change in anatomical orientation of heart within the thorax resulting in alteration of electrical axis of the heart.