pituitrin and Glioma

Brain microvascular endothelial cells play an important role in regulation of ion and fluid movement between the blood and the brain interstitium. Astrocytes have been shown to induce blood-brain barrier properties in the endothelial cells, including formation of tight junctions and increased expression and asymmetric distribution of enzymes and ion transport systems. Previous studies have demonstrated that endothelial cells of bovine aorta possess a highly active Na-K-Cl cotransport system that participates in intracellular volume regulation. The present study was conducted to evaluate Na-K-Cl cotransport activity of cerebral microvascular endothelial cells and to determine whether astrocyte-conditioned medium (CM) influences Na-K-Cl cotransport activity of these cells. We found the brain microvascular endothelial cells to exhibit a robust Na-K-Cl cotransport activity, comprising 50% of the total K influx. Activity of the cotransporter was stimulated by agents that elevate intracellular Ca and by hypertonicity and was inhibited by agents that elevate adenosine 3',5'-cyclic monophosphate, guanosine 3',5'-cyclic monophosphate, or activate protein kinase C. Exposure of the cells to primary astrocyte- or C6 glial cell-CM but not A7r5 or A10 vascular smooth muscle cell-CM also increased cotransport activity. However, this effect required > 1 h of exposure to CM, was additive with the effects of vasopressin, calcium ionophore, and hypertonicity, and was blocked by the protein synthesis inhibitor cycloheximide.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Aorta; Astrocytes; Brain; Bumetanide; Calcimycin; Carrier Proteins; Cattle; Culture Media, Conditioned; Cycloheximide; Endothelium, Vascular; Glioma; Kinetics; Microcirculation; Ouabain; Potassium; Rats; Sodium-Potassium-Chloride Symporters; Tumor Cells, Cultured; Vasopressins

Topics: Animals; Bradykinin; Cell Line; Enkephalins; Enzyme Activation; Glioma; Insulin-Like Growth Factor I; Interleukin-1; Kinetics; Nerve Growth Factors; Neuroblastoma; Phosphatidylinositol 3-Kinases; Phosphotransferases; Transforming Growth Factor beta; Vasopressins

Hyponatremia, in patients with central nervous system disease, can be attributable to impaired free water excretion (syndrome of inappropriate secretion of antidiuretic hormone) or to excessive sodium excretion (cerebral salt wasting). We present a patient with a parietal glioma and hyponatremia characterized by salt wasting and dehydration. Rehydration and sodium repletion corrected the sodium and volume deficits; withdrawal of supplemental sodium resulted in recurrence of dehydration and hyponatremia. We determined sodium and water balance and measured plasma atriopeptin, antidiuretic hormone, and aldosterone. Plasma atriopeptin ranged from 8 to 44 pg/mL (normal, less than 45 pg/mL); antidiuretic hormone was not elevated at 4 to 5 pg/mL, and aldosterone was slightly elevated at 1040.25 pmol/L. The concentrations of these hormones could not directly explain the natriuresis; interactions with neural or other humoral factors may be involved. In evaluating such patients, careful attention to sodium and water balance is important to guide appropriate therapy.

Topics: Adult; Aldosterone; Brain Neoplasms; Dehydration; Glioma; Humans; Hyponatremia; Male; Sodium; Vasopressins; Water-Electrolyte Balance

Topics: Brain Neoplasms; Craniopharyngioma; Drug Therapy, Combination; Female; Glioma; Humans; Male; Methylprednisolone; Vasopressins

Topics: Blood; Brain Neoplasms; Child; Dehydration; Glioma; Humans; Hyponatremia; Hypothalamus; Osmolar Concentration; Sodium; Urine; Vasopressins; Water-Electrolyte Balance

Topics: Adenine Nucleotides; Aldosterone; Brain Neoplasms; Child; Ethanol; Glioma; Humans; Hypertonic Solutions; Hyponatremia; Hypothalamus; Male; Osmolar Concentration; Vasopressins; Water-Electrolyte Balance

Topics: Brain Neoplasms; Carcinoma, Bronchogenic; Cerebral Cortex; Dementia; Glioma; Humans; Hyponatremia; Liver Neoplasms; Lymph Nodes; Male; Mental Disorders; Middle Aged; Neoplasm Metastasis; Seizures; Sodium; Thalamus; Vasopressins

Topics: Adolescent; Adrenocorticotropic Hormone; Adult; Craniocerebral Trauma; Diabetes Insipidus; Female; Glioma; Hodgkin Disease; Humans; Hypothalamo-Hypophyseal System; Male; Metyrapone; Middle Aged; Neurotransmitter Agents; Pinealoma; Pituitary Gland; Pituitary-Adrenal Function Tests; Skull Neoplasms; Vasopressins; Water-Electrolyte Balance