RESUMO
Case of a patient with acute myeloid leukemia (AML) positive for mutations in both genes NPM1 and FLT3-ITD who underwent two allogeneic haematopoietic stem cell transplants (HSCT); the second allograft one was followed by extramedullary relapse (granulocytic sarcoma of right breast), with blast cells positive for FLT3-ITDmutation. Treatment with Gilteritinib, a second generation selective oral type I FLT3 inhibitor, was started after the second HSCT with complete regression of breast granulocytic sarcoma in absence of hematological and extra hematologic toxicity. We conclude that Gilteritinib can represent an effective therapy for extra hematologic relapse, with acceptable toxicity and outpatient management.
RESUMO
Several guidelines have been published about management of chronic GvHD (cGvHD), but the clinical practice still remains demanding. The Gruppo Italiano Trapianto di Midollo Osseo (GITMO) has planned a prospective observational study on cGvHD, supported by a dedicated software, including the updated recommendations. In view of this study, two surveys have been conducted, focusing the management of cGvHD and ancillary therapy in cGvHD, to address the current 'real life' situation. The two surveys were sent to all 57 GITMO centers, performing allografting in Italy; the response rate was 57% and 66% of the interviewed centers, respectively. The first survey showed a great disparity especially regarding steroid-refractory cGvHD, although extracorporeal photo-apheresis resulted as the most indicated treatment in this setting. Another challenging issue was the strategy for tapering steroid: our survey showed a great variance, and this disagreement could be a real bias in evaluating outcomes in prospective studies. As for the second survey, the results suggest that the ancillary treatments are not standardized in many centers. All responding centers reported a strong need to standardize management of cGvHD and to participate in prospective trials. Before starting observational and/or interventional studies, a detailed knowledge of current practice should be encouraged.
Assuntos
Doença Enxerto-Hospedeiro/terapia , Doença Crônica , Feminino , Doença Enxerto-Hospedeiro/patologia , Humanos , Itália , MasculinoRESUMO
AIM: The biology of colorectal hyperplastic polyps is of considerable relevance, because recent evidence suggests that under certain circumstances hyperplastic polyps may be precursors of neoplasms. The aim of this study was to assess and compare the clinical and molecular characteristics of hyperplastic polyps and neoplastic lesions removed from patients without the hyperplastic polyposis syndrome. METHODS: One hundred and twenty six patients were identified through a series of genetic epidemiological studies. Each patient had at least one neoplastic lesion and one hyperplastic polyp; there was a total of 147 hyperplastic polyps. All lesions were evaluated for K-ras mutations, loss of heterozygosity (LOH) of the adenomatous polyposis coli (APC) gene, and microsatellite instability. RESULTS: K-ras mutation was detected in 15 (10%) hyperplastic polyps, all from the rectosigmoid colon. No hyperplastic polyp had APC LOH or microsatellite instability. Patients with adenomas or carcinomas showing K-ras mutations were not more likely to have hyperplastic polyps with K-ras mutations. The average number of adenomas did not differ between those patients with hyperplastic polyps with K-ras mutations and those without K-ras mutations. There was no association between the hyperplastic polyp and the adenoma regarding the colon segments from which the two lesions were removed. CONCLUSIONS: The sporadic hyperplastic polyp is a lesion with limited molecular change and no relation to patients' neoplastic lesions.
Assuntos
Adenoma/genética , Carcinoma/genética , Colo/patologia , Neoplasias do Colo/genética , Pólipos do Colo/genética , Adenoma/patologia , Idoso , Carcinoma/patologia , Neoplasias do Colo/patologia , Colonoscopia , Feminino , Genes APC , Genes ras , Humanos , Hiperplasia/patologia , Perda de Heterozigosidade , Masculino , Repetições de Microssatélites , Pessoa de Meia-Idade , Mutação , Reação em Cadeia da Polimerase/métodosRESUMO
BACKGROUND: One method to assess loss of heterozygosity (LOH) of various genes is the amplification of DNA from neoplastic tissue by using microsatellite markers. LOH can best be considered on a quantitative basis as a comparison of allelic ratios of neoplastic tissue to that of the normal control. We will illustrate through quantitative methods the importance of using the appropriate controls when determining allelic loss. METHODS AND RESULTS: DNA extracted from 28 paired blood and formalin-fixed, paraffin-embedded normal mucosal tissue was amplified using the DP1 microsatellite marker, consisting of a variable number of CA repeats. This marker is located within the D5S346 (DP1) region on chromosome 5 and is linked to the adenomatous polyposis coli gene. Allelic ratios were calculated after scanning autoradiographs on a densitometer. Ratio values approaching 1 were observed when the two alleles were close in molecular weight, whereas ratios less than 1 were detected when the two alleles had very different molecular weights. This discrepancy was more pronounced in paraffin-embedded tissue than with blood samples. CONCLUSION: For LOH amplification assays, it is best to use normal control samples that are of the same tissue source as the neoplastic sample being analyzed. When assessing LOH in neoplastic tissue, a quantitative value rather than visual assessment of the alleles should be considered. The values may be normalized by dividing the ratio of the two tumor alleles by the ratio of the two normal alleles.
Assuntos
Células Sanguíneas/química , Colo/química , DNA/genética , Mucosa Intestinal/química , Perda de Heterozigosidade , Reação em Cadeia da Polimerase/métodos , Alelos , Cromossomos Humanos Par 5/genética , DNA/sangue , DNA/isolamento & purificação , Densitometria , Marcadores Genéticos , Humanos , Repetições de Microssatélites , Inclusão em ParafinaRESUMO
Studies were designed to determine a) if adrenal glands of hamsters secrete progesterone (PROG), b) the effects of adrenocritocotropin (ACTH) administration on adrenocortial function of rats and hamsters under the surgical conditions necessary for collection of adrenal venous blood from the left renal vein, and c) the effects of blood loss during sample collection. PROG was quantitated by the competitive protein-binding method after extraction and separation by sephadex LH-20 column chromatography. The presence of interfering quantities of androstenedione necessitated two column chromatographic steps. Glucocorticoids (11-OHCS) were determined fluorometrically. PROG was detected in adrenal venous plasma of female hamsters. The PROG concentration and secretory rate were 91 +/- 12 ng/ml and 4 +/- 1 ng/min, respectively, while the peripheral plasma level of the same animals was 2 +/- 0.2 ng/ml, indicating that the adrenal glands of female hamsters are capable of secreting PROG. ACTH administration increased PROG secretory rates in both hamsters (3 +/- 1 to 14 +/- 3 ng/min) and rats (62 +/- 9 to 152 +/- 32 ng/min) on estrus, as well as increasing the 11-OHCS secretory rate of hamsters (16 +/- 1 to 33 +/- 4 ng/min), but not of rats. The greater increase in PRCC than in 11-OHCS secretion may be related to excess PROG formation relative to the capacity of the 17alpha- or 21-hydroxylating enzyme systems. The adrenal venous PROG concentration and secretory rate of female hamsters infused with 10% dextran while collecting adrenal venous blood did not differ significantly from those of the non-infused animals, suggesting that this amount of blood loss (1 ml) does not influence PROG secretion.
Assuntos
Glândulas Suprarrenais/metabolismo , Hormônio Adrenocorticotrópico/farmacologia , Progesterona/metabolismo , Glândulas Suprarrenais/efeitos dos fármacos , Adrenalectomia , Animais , Ligação Competitiva , Cricetinae , Estro/efeitos dos fármacos , Feminino , Cinética , Gravidez , Progesterona/sangue , Ensaio Radioligante , Ratos , Especificidade da EspécieRESUMO
Adrenal secretory rates and peripheral plasma levels of progesterone (PROG) were determined during the estrous cycles of hamsters and 4-day cyclic rats. In both species, the PROG concentrations in peripheral plasma were never more than 6% of those observed in adrenal venous plasma. In hamsters, adrenal PROG secretory rates varied from 3.8 +/- 0.8 ng/min at 0800 hr on proestrus (P) to 8.5 +/- 1 ng/min at 2000 hr on estrus (E). The rates noted on P were among the lowest observed and were similar to those noted at 0800 hr the following morning. In rats, adrenal PROG secretory rates varied from 57 +/- 9 ng/min at 0800 hr on E to 130 +/- 18 ng/min at 2000 hr on P. A significant decline occurred between 2000 hr on P and 0800 hr the following morning. Rats secreted 3 to 8 times more PROG than did hamsters when the secretory rates are expressed as ng/min/100 mg adrenal. In hamsters, the data suggest a relative lack of influence of female reproductive hormones on adrenal PROG secretion and in turn the latter may not be involved in reproductive hormonal changes leading to ovulation. In rats, the increased adrenal PROG secretion noted on P may be due to the influence of reproductive hormones on adrenocortical function. This elevated rate may in turn influence the hypothalamo-hypophyseal-ovarian axis.
Assuntos
Glândulas Suprarrenais/metabolismo , Estro , Progesterona/metabolismo , Animais , Cricetinae , Feminino , Mesocricetus , Gravidez , Progesterona/sangue , Ratos , Especificidade da Espécie , Fatores de TempoRESUMO
The findings that all HPA and SAM indexes increased during the first postoperative days strongly suggest that transvenous, permanent cardiac pacemaker implantation is a stressor. Since the psychologic tests did not demonstrate marked changes in anxiety or affective mood states, and the former was only weakly related to the endocrine responses, psychologic stimuli cannot be ascribed a prominent role in causing the observed endocrine alterations. Thus, the data suggest that physiologic stressors, such as surgical trauma and the irritation of the tissue surrounding the pacemaker, were the primary stimuli that activated the HPA and SAM systems. Although the structured teaching program resulted in a marked improvement of the treatment groups's knowledge of the device and the follow-up care it requires, it did not affect the endocrine or psychologic responses of patients to cardiac pacemaker implantation.
Assuntos
Epinefrina/urina , Glicóis/urina , Hidrocortisona/urina , Metoxi-Hidroxifenilglicol/urina , Norepinefrina/urina , Marca-Passo Artificial/efeitos adversos , Adulto , Idoso , Ansiedade/etiologia , Emoções , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Educação de Pacientes como Assunto , Testes Psicológicos , Projetos de PesquisaRESUMO
Anesthetized dogs, which had been prepared with lumboadrenal vein cannulae, were intravenously infused with monoamine axidase (alphaETA), tryptophan hydroxylase (pCPA) or tyrosine hydroxylase (alphaMT) inhibitors 30 min prior to exposure to 10% oxygen at ground level. These studies were designed to ascertain the role of the neurotransmitters, serotonin and norepinephrine, in the adrenocortical response to hypoxia. In normoxic animals, alphaETA decreased basal cortisol secretion and increased systolic pressure, whereas pCPA and alphaMT were essentially without afffect on these parameters. All inhibitors prevented the rise in cortisol secretion usually observed in hypoxic dogs. Alpha ETA appeared to inhibit the adrenocortical response to hypoxia as a result of its potent pressore activity, while pCPA and alphaMT inhibited cortisol secretion by interfering with the synthesis of serotonin and norepinephrine, respictively. These data suggest that substances which alter the content and/or turnover of brain monoamines abolish the hypoxic rise in cortisol secretion and thus would lower the resistance of the animal to this stressor.
Assuntos
Hidrocortisona/metabolismo , Hipóxia/metabolismo , Norepinefrina/metabolismo , Serotonina/metabolismo , Glândulas Suprarrenais/irrigação sanguínea , Glândulas Suprarrenais/metabolismo , Animais , Pressão Sanguínea/efeitos dos fármacos , Cães , Fenclonina/farmacologia , Frequência Cardíaca/efeitos dos fármacos , Hipóxia/fisiopatologia , Masculino , Metiltirosinas/farmacologia , Inibidores da Monoaminoxidase/farmacologia , Fluxo Sanguíneo Regional/efeitos dos fármacos , Respiração/efeitos dos fármacos , Triptofano Hidroxilase/antagonistas & inibidores , Tirosina 3-Mono-Oxigenase/antagonistas & inibidoresRESUMO
Cholinergic neuronal influences on the function of male rat's hypothalamo-hypophyseal-adrenocortical (HHA) system both during basal and stressful situations (hypoxia and hypercapnia) were investigated using a cholinergic agonist (eserine) and antagonists (atropine, methyl atropine, mecamylamine and 4-(1-naphthylvinyl) pyridine). The results indicate that the transmitter, acetylcholine (ACh), plays a partial role in the regulation of the HHA system. The muscarinic (m) effects of ACh were stimulatory peripherally and inhibitory centrally. The nicotinic (n) effects were stimulatory and possibly affected the HHA system by inhibiting the central m-inputs. The cholinergic regulation of the HHA system for both non-stressed and hypercapnic animals is probably mediated via a common nm-cholinergic pathway.
Assuntos
Córtex Suprarrenal/fisiologia , Glândulas Suprarrenais/fisiologia , Hipercapnia/fisiopatologia , Hipóxia/fisiopatologia , Parassimpatolíticos/farmacologia , Parassimpatomiméticos/farmacologia , Córtex Suprarrenal/efeitos dos fármacos , Hormônio Adrenocorticotrópico/farmacologia , Animais , Atropina/farmacologia , Derivados da Atropina/farmacologia , Corticosterona/sangue , Dexametasona/farmacologia , Masculino , Mecamilamina/farmacologia , Naftilvinilpiridina/farmacologia , Fisostigmina/farmacologia , Ratos , Fatores de TempoRESUMO
Adrenocortical nycthemeral (day-night alteration) and hypoxic stress responses of rats were evaluated 48 h following 70% hepatectomy. Morning plasma and adrenal corticosterone concentrations of hepatectomized (H) rats at 0800 hours were significantly higher than those of sham (S) operated animals. Although both groups showed significant nocturnal elevations in these parameters at 2000 hours, the nocturnal rises in plasma corticosterone levels were 75% and 223% in H and S rats, respectively, yet the absolute steroid levels did not differ between the groups. The hypothalamic-pituitary-adrenocortical (HPA) response of H animals to hypoxia was assessed by measuring plasma corticosterone levels at various times before, during and after exposure to 10% O2 at ground level. Curvilinear analysis of the plasma steroid levels revealed a significantly slower corticosterone rise during the hypoxic phase in H than S animals, as well as a much slower return to baseline levels after the hypoxic stimulus was terminated. The latter indicates a decreased hepatic capacity to inactivate steroids in H animals, while the sluggish activation of the HPA system by hypoxia may be due to altered neuroendocrine control resulting from prior exposure of feedback sites to elevated basal plasma corticosterone levels.
Assuntos
Córtex Suprarrenal/fisiopatologia , Hepatectomia , Hipóxia/fisiopatologia , Córtex Suprarrenal/metabolismo , Animais , Ritmo Circadiano , Corticosterona/sangue , Corticosterona/metabolismo , Sistema Hipotálamo-Hipofisário/fisiopatologia , Masculino , Tamanho do Órgão , Sistema Hipófise-Suprarrenal/fisiopatologia , RatosAssuntos
Anemia Aplástica/tratamento farmacológico , Anticorpos Monoclonais Humanizados/uso terapêutico , Hemoglobinúria Paroxística/tratamento farmacológico , Terapia de Imunossupressão/métodos , Adulto , Idoso , Anemia Aplástica/patologia , Anticorpos Monoclonais Humanizados/farmacologia , Hemoglobinúria Paroxística/patologia , Humanos , Estudos Retrospectivos , Adulto JovemAssuntos
Eritrócitos/metabolismo , Hidrocortisona/sangue , Animais , Transporte Biológico , Cálcio/farmacologia , Permeabilidade da Membrana Celular , Cães , Ácido Edético/farmacologia , Eritrócitos/efeitos dos fármacos , Cinética , Masculino , Plasma , Potássio/farmacologia , Análise de Regressão , Cloreto de Sódio/farmacologia , Soluções , Fatores de TempoRESUMO
Acetylcholine and norepinephrine play important roles in determining gastrointestinal (GI) tract motility and secretion. At this time, however, little is known concerning the postnatal developmental patterns of the enzymes that synthesize and degrade these two neurotransmitters within the GI tract. The present study examined the developmental activities, expressed per gram protein per minute, of the cholinergic enzymes choline acetyltransferase (ChAT) and acetylcholine esterase (AChE) and the adrenergic enzymes tyrosine hydroxylase (TH) and monoamine oxidase (MAO) in male rats between days 1 and 50. Seven anatomic segments of the GI tract were assayed for enzyme activities. In general, all four neurotransmitter enzymes were present throughout the length of the GI tract and increased during the early postnatal period. The synthesizing enzymes ChAT and TH displayed peak activity prior to day 21, while the degrading enzymes AChE and MAO continued to increase past day 21. Each enzyme exhibited segmental differences and unique postnatal developmental patterns. Such differences in enzyme activities may be related to developmental increases in neuronal density, hormonal factors, or direct stimulation of the GI tract by liquid and/or solid diet.
Assuntos
Acetilcolinesterase/metabolismo , Colina O-Acetiltransferase/metabolismo , Sistema Digestório/crescimento & desenvolvimento , Monoaminoxidase/metabolismo , Tirosina 3-Mono-Oxigenase/metabolismo , Envelhecimento , Animais , Sistema Digestório/enzimologia , Fundo Gástrico/enzimologia , Intestino Grosso/enzimologia , Intestino Delgado/enzimologia , Masculino , Neurotransmissores/metabolismo , Ratos , Distribuição TecidualRESUMO
The in vitro secretion of aldosterone and corticosterone by the adrenal glands of fetal (day 30), pregnant and non-pregnant rabbits was examined under basal and stimulated conditions. In general, non-pregnant animals basally secreted less aldosterone than either pregnant or fetal rabbits, whereas basal corticosterone secretion by pregnant animals exceeded that of either fetal or non-pregnant animals. At similar doses of adrenocorticotropin (ACTH), fetal and pregnant adrenal glands produced comparatively more aldosterone than non-pregnant animals, while corticosterone secretion was accelerated to a greater degree in fetal rabbits than in the other groups. Angiotensin II had its greatest effect on the aldosterone secretory rates of fetal and non-pregnant animals without affecting corticosterone secretion in any group. Elevated potassium (K+) enhanced the secretory rates of aldosterone and corticosterone in fetal animals, while increasing only aldosterone secretion in non-pregnant rabbits. Serotonin accelerated aldosterone secretion in all animals, whereas it increased corticosterone secretion only in non-pregnant animals. These results suggest that (1) in fetal rabbits, the secretory rates of both aldosterone and corticosterone are regulated primarily by ACTH and to a much lesser extent by angiotensin II and K+, (2) the corticosterone secretory rates of pregnant and non-pregnant rabbits are controlled mainly by ACTH, and (3) aldosterone secretion by non-pregnant animals is regulated primarily by angiotensin II and secondarily by ACTH and K+, while in pregnant animals ACTH may be the primary regulator of aldosterone secretion as it is in the fetus.
Assuntos
Glândulas Suprarrenais/metabolismo , Aldosterona/metabolismo , Corticosterona/metabolismo , Prenhez , Glândulas Suprarrenais/embriologia , Hormônio Adrenocorticotrópico/farmacologia , Angiotensina II/farmacologia , Animais , Relação Dose-Resposta a Droga , Feminino , Técnicas In Vitro , Potássio/farmacologia , Gravidez , Coelhos , Taxa Secretória/efeitos dos fármacos , Serotonina/farmacologiaRESUMO
Manipulation of diet, by altering the composition or quantity, can produce alterations in the central nervous system as evidenced by changes in memory or behavior. The present study was designed to examine the effects of fasting/starvation or a choline deficient diet on the enzymes that synthesize and degrade acetylcholine and norepinephrine, both neurotransmitters in the gastrointestinal tract. This study was conducted on three groups of male rats: control nontreated, choline deficient diet for 14 days, and fasting/starvation (water only) for 3 days. Enzyme activities were determined throughout the length of the gut. The lack of dietary choline produced a decrease in adrenergic enzyme activity but had little effect on cholinergic enzyme activities. Starvation decreased adrenergic enzyme activities and increased activity of the acetylcholine synthesizing enzyme in most segments of the gastrointestinal tract. Starvation was also a stressor, as evidenced by elevated levels of plasma and adrenal corticosterone. The implication from these experiments is that dietary manipulation may produce functional changes (i.e., motility and secretion) in the gastrointestinal tract as a result of altering neurotransmitter enzyme activities.
Assuntos
Acetilcolinesterase/análise , Colina O-Acetiltransferase/análise , Dieta , Sistema Digestório/enzimologia , Animais , Deficiência de Colina/metabolismo , Corticosterona/análise , Jejum , Masculino , Monoaminoxidase/análise , Ratos , Ratos Endogâmicos , Inanição/metabolismo , Tirosina 3-Mono-Oxigenase/análiseRESUMO
Adrenal glucocorticoids have been shown to produce alterations in the enzymes which synthesize and degrade cholinergic and catecholaminergic neurotransmitters in the central and peripheral nervous system. The present study examined the impact of altering plasma corticosterone levels via corticosterone or metyrapone ingestion, via the drinking water, on the developmental profile of choline acetyltransferase (ChAT), acetylcholine esterase (AChE), tyrosine hydroxylase (TH) and monoamine oxidase (MAO) in various gastrointestinal (GI) segments of rats. Three groups were studied: non-treated, corticosterone treated and metyrapone treated. Drug intake of pregnant (i.e., beginning on the 15th day of gestation), lactating and weaned rats was monitored until the male pups were sacrificed at 1, 3, 7, 14, 21, 35 and 50 days of age. Results showed that ChAT and TH activities peaked earlier in development in corticosterone treated rats as compared to non-treated and metyrapone treated rats. During the early postnatal period plasma corticosterone levels were inversely related to AChE and MAO activities in most GI segments. These results indicate that neurotransmitter enzyme activities in various GI segments are influenced by corticosterone during a critical period of development.
Assuntos
Corticosterona/sangue , Sistema Digestório/enzimologia , Metirapona/farmacologia , Acetilcolinesterase/metabolismo , Animais , Colina O-Acetiltransferase/metabolismo , Corticosterona/farmacologia , Sistema Digestório/efeitos dos fármacos , Sistema Digestório/crescimento & desenvolvimento , Feminino , Masculino , Troca Materno-Fetal , Monoaminoxidase/metabolismo , Gravidez , Ratos , Ratos Endogâmicos , Tirosina 3-Mono-Oxigenase/metabolismoRESUMO
Cholinergic involvement in the regulation of the hypothalamic-pituitary-adrenocortical (HPA) system of male rats was evaluated using muscarinic (atropine and methacholine) and nicotine (mecamylamine and nicotine) agents, which were selected for their specificity on cholinergic receptors (ChR). They were administered either intracerebroventricularly (icv) to produce central effects, or ip to produce both central and peripheral effects, prior to subjecting the animals to either auditory or hypercapnic stress for 1 h. Plasma corticosterone was used as an index of HPA activity. The results suggest that central muscarinic ChR are involved in inhibiting HPA activity in both non-stressed and stressed animals, whereas central nicotinic ChR are excitatory during stress but inactive in the non-stressed state. Stimulation of peripheral nicotinic ChR appeared to potentiate the HPA response to hypercapnia, and to inhibit the central excitatory nicotinic ChR when the latter were activated in non-stressed and auditory stress rats. These data suggest that during auditory stress the HPA system is more dependent upon the cholinergic system for its activation than during non-stressed and hypercapnic states.
Assuntos
Sistema Hipotálamo-Hipofisário/fisiologia , Sistema Nervoso Parassimpático/fisiologia , Sistema Hipófise-Suprarrenal/fisiologia , Estresse Fisiológico/fisiopatologia , Estimulação Acústica , Animais , Atropina/farmacologia , Corticosterona/sangue , Dexametasona/farmacologia , Hipercapnia/fisiopatologia , Injeções Intraperitoneais , Injeções Intraventriculares , Masculino , Mecamilamina/farmacologia , Compostos de Metacolina/farmacologia , Nicotina/farmacologia , Ratos , Receptores Colinérgicos/efeitos dos fármacos , Receptores Muscarínicos/efeitos dos fármacos , Receptores Nicotínicos/efeitos dos fármacos , Vasopressinas/farmacologiaRESUMO
Intact dog adrenal glands were examined for their phosphate profiles in the 31P nuclear magnetic resonance spectrometer at 36.43 MHz at 31 degrees, and the resultant spectra were compared to those obtained from perchloric acid extracts of the same endocrine tissue. The adrenal gland presents a unique organ for whole tissue spectroscopy in that its phosphate profile shows a number of features which have not been previously observed in similar phosphate profiles obtained from other intact tissue preparations. A number of prominant resonances are observed in the intact adrenal gland which arise from phosphorus-containing substances that are not extractable with perchloric acid. The 31P shifts of these resonances indicate that they may arise from phosphorylated proteins and membrane phospholipids.
Assuntos
Glândulas Suprarrenais/metabolismo , Fosfatos/metabolismo , Nucleotídeos de Adenina/metabolismo , Animais , Cães , Espectroscopia de Ressonância Magnética , Masculino , Fosfatidiletanolaminas/metabolismoRESUMO
The effects of altering the concentrations of various cerebrospinal fluid (CSF) cations on hypothalamo-hypophyseal-adrenocortical (HHA) activity were investigated in conscious cats. The cerebroventricles were perfused with CSF containing high or low [Na+], [K+], [Li+], [Ca2+] and [Mg2+] for 60 min and plasma samples taken periodically for analysis of cortisol. The results demonstrate that changing CSF [Na+] or [Li+] does not substantially alter plasma cortisol levels. Although individually elevating CSF [K+], [Ca2+] or [Mg2+] does not affect plasma cortisol levels, reducing these CSF cations activates the HHA system and the latter in turn is inhibited by the addition of dexamethasone (DEX) to low cation CSF. The excitatory action of reduced [Ca2+] is also inhibited by the addition of norepinephrine to the perfusion fluid, suggesting that lowering this cation affects the HHA system by preventing the release of the adrenergic neurotransmitter. Furthermore, these data suggest that in conscious unrestrained cats basal HHA activity is dependent to some extent upon normal brain extracellular [K+], [Ca2+] and [Mg2+].