Involvement of Carrier-Mediated Transport at the Blood-Cerebrospinal Fluid Barrier in Spermine Clearance from Rat Brain.

Spermine is the end-product in the polyamine biosynthetic pathway, and its excess accumulation induces neuroexcitatory responses and neurotoxicity. The purpose of this study was to elucidate the involvement of transport systems at the brain barriers in the clearance of spermine. In vivo rat spermine elimination from brain parenchyma across the blood-brain barrier (BBB) and blood-cerebrospinal fluid (CSF) barrier (BCSFB) was assessed by intracerebral and intracerebroventricular administration techniques, respectively. To characterize spermine transport at the BCSFB, a transport study using rat choroid plexus was performed. After the intracerebral microinjection of [3H]spermine, no time-dependent decrease in [3H]spermine in the ipsilateral cerebrum was observed, suggesting the low contribution of the BBB to spermine clearance from the brain. In contrast, the [3H]spermine concentration in the CSF after intracerebroventricular administration was time-dependently decreased with an elimination rate constant of 0.352 min-1, and the elimination clearance of [3H]spermine was 6.6-fold greater than that of [14C]D-mannitol, reflecting bulk flow of the CSF. This [3H]spermine elimination was attenuated by co-administration of unlabeled excess spermine, indicating carrier-mediated elimination of spermine from the CSF. [3H]Spermine transport into the choroid plexus was strongly inhibited by unlabeled spermine, other polyamines (spermidine and putrescine), and organic cation transporter substrates such as corticosterone and 1-methyl-4-phenylpyridinium. However, other substrates/inhibitors for organic cation transporters (decynium-22 and tetraethylammonium) had little effect. Consequently, our study indicates that transporting molecules at the BCSFB, distinct from typical organic cation transporters, are involved in spermine clearance from the CSF.

'Smelling' the cerebrospinal fluid: olfactory signaling molecules are expressed in and mediate chemosensory signaling from the choroid plexus.

The olfactory-type signaling machinery has been known to be involved not only in odorant detection but also in other tissues with unsuspected sensory roles. As a barrier, the choroid plexus (CP) is an active participant in the monitoring of the cerebrospinal fluid (CSF), promptly responding to alterations in its composition. We hypothesized that olfactory signaling could be active in CP, contributing to the surveillance of the CSF composition. We determined the mRNA and protein expression of the major components of the olfactory transduction pathway in the rat CP, including odorant receptors, the olfactory G-protein (Gαolf), adenylate cyclase 3 and cyclic nucleotide-gated channel 2. The functionality of the transduction pathway and the intracellular mechanisms involved were analyzed by DC field potential recording electrophysiological analysis, in an ex vivo CP-brain setup, using polyamines as stimuli and blockers of the downstream signaling pathways. Concentration-dependent responses were obtained for the polyamines studied (cadaverine, putrescine, spermine and spermidine), all known to be present in the CSF. Transfection of a CP epithelial cell line with siRNA against Gαolf effectively knocked down protein expression and reduced the CP cells' response to spermine. Thus, the key components of the olfactory chemosensory apparatus are present and are functional in murine CP, and polyamines seem to trigger both the cAMP and the phospholipase C-inositol 1,4,5-trisphosphate pathways. Olfactory-like chemosensory signaling may be an essential component of the CP chemical surveillance apparatus to detect alterations in the CSF composition, and to elicit responses to modulate and maintain brain homeostasis.

Determination of polyamines in human tissues by precolumn derivatization with 9-fluorenylmethyl chloroformate and high-performance liquid chromatography.

A high-performance liquid chromatography (HPLC) assay with fluorescence detection was developed for the determination of the polyamines putrescine, spermidine, spermine in samples of human spinal cord, cerebellum, cerebrospinal fluid (CSF), skeletal muscle, and muscle microdialysates without an extensive sample preparation. The precolumn derivatization was performed with 9-fluorenylmethyl chloroformate (FMOC), and the derivatizated polyamines were stable for at least 14 h at 4 degrees C. All polyamines were separated within 35 min. The method was checked for linearity, and mean correlation coefficient values of 0.995, 0.999, and 0.991 were achieved for putrescine, spermidine, and spermine, respectively. The within- and between-assay coefficient of variation percentages evaluated in standard solutions varied between 1.0 and 4.9% and between 1.3 and 6.9%, respectively. The corresponding values obtained in samples of human spinal cord were between 1.0 and 5.0% and between 0.6 and 5.8%. The values of the recovery, evaluated in spinal cord tissue, varied between 83.7 and 93.5%.

Atmospheric pressure chemical ionization-mass spectrometry method to improve the determination of dansylated polyamines.

Determination of polyamine pools is still a step impossible to circumvent in studies aimed at determining the pathophysiological role of natural polyamines. In addition, polyamine measurement in biological fluids and tissues may have clinical relevance, especially in cancer patients. Among the wide panel of analytical methods developed for the quantification of polyamines, high-performance liquid chromatographic (HPLC) separation of polyamines after derivatization with dansyl chloride remains the most commonly used method. In this work, we show that atmospheric pressure chemical ionization-mass spectrometry (MS) can be used to detect and quantify biologically relevant polyamines after dansylation, without chromatographic separation. Positive-ion mass spectra for each dansylated polyamine were generated after optimization by flow injection analysis (FIA). FIA coupled with MS detection by selected ion monitoring greatly increased the sensitivity of the polyamine detection. The method is linear over a wide range of polyamine concentrations and allows detection of quantities as low as 5 fmol. The FIA/MS method is about 50-fold more sensitive than the conventional HPLC/fluorimetry procedure. A good correlation (r>0.98) between these two methods was observed. The FIA/MS method notably reduces the time of analysis per sample to 1.5 min and turns out to be rapid, efficient, cost saving, reproducible, and sufficiently simple to allow its routine application.

[Measurements of CSF biochemical tumor markers in patients with meningeal carcinomatosis].

CSF beta--glucuronidase, polyamines and carcinoembryonic antigen (CEA) were analyzed in 16 patients with meningeal carcinomatosis from solid tumors in systemic organs, 27 with benign brain lesions, 11 with primary brain tumors, 14 with metastatic brain tumors and 5 with leptomeningeal dissemination of other malignant diseases. beta--glucuronidase levels in all cases of meningeal carcinomatosis, meningeal gliomatosis and meningeal lymphoma were higher than 100 micrograms/dl/hr. On the other hand, levels in all cases of benign brain lesions were below 100 micrograms/dl/hr. Levels of beta--glucuronidase in the cases of metastatic brain tumors returned to normal levels after tumor resection. Levels of beta--glucuronidase and polyamines were not high in the cases with positive cytology in CSF after tumor resection. The polyamine level seemed to be dependent on the growth rate of the disease and was shown to below 0.05 nmol/ml in all cases after resection of the metastatic brain tumors. Cystic fluid of both benign and malignant tumor showed high levels of beta--glucuronidase and polyamines except for spermidine and spermine levels in a suprasellar cyst. Some cases of meningeal carcinomatosis with high levels of serum CEA did not always show high levels of CSF CEA. In the surgical cases with a metastatic brain tumor, the cases with leptomeningeal, especially dural attachment showed high levels of beta--glucuronidase and CEA preoperatively, but they returned to normal after surgery. In 2 cases of meningeal carcinomatosis treated by intrathecal chemotherapy with MTX and Ara-C, CSF beta--glucuronidase and CEA showed clinical condition better than the cell count in CSF decreased rapidly following chemotherapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Determination of polyamines and metabolites in cerebrospinal fluid by isotope dilution mass fragmentography, and a clinical application.

Capillary gas chromatography and mass fragmentography was used to determine simultaneously 1,3-diaminopropane, putrescine, cadaverine, spermidine, spermine, isoputreanine and putreanine in cerebrospinal fluid. After addition of deuterium labelled analogs and acid hydrolysis, the compounds were isolated by adsorption onto silica and converted into their N-heptafluorobutyryl-methylesters. Quality control data and an application of the method are given. A patient harbouring an astrocytoma was monitored during chemotherapeutic treatment.

Solid-phase extraction and determination of dansyl derivatives of unconjugated and acetylated polyamines by reversed-phase liquid chromatography: improved separation systems for polyamines in cerebrospinal fluid, urine and tissue.

A sensitive and simple liquid chromatographic assay with fluorometric detection for unconjugated and acetylated polyamines in biological fluids is described. After precolumn derivatization with dansyl chloride, unconjugated polyamines and acetylated polyamines were extracted by elution from a Bond-Elut C18 column and then separated on a reversed-phase column with gradient elution. The complete analysis of unconjugated putrescine, spermidine, and spermine in either hydrolyzed urine, cerebrospinal fluid or tissue could be accomplished within 20-26 min, while the simultaneous analysis of unconjugated polyamines and monoacetylpolyamines could be completed within 40 min. Unhydrolyzed urine and cerebrospinal fluid required a Bond-Elut cation-exchange clean-up before dansylation. Standard curves for the assay were linear up to 20 nmol/ml, and the within-day and day-to-day coefficients of variation were between 1.1 and 4.6% and between 1.6 and 11.8%, respectively. Results obtained with the method were compared with results obtained with a well established modified amino acid analyzer method for urine, tissue and cerebrospinal fluid samples. The correlation coefficients between these two methods were in the range 0.933-0.996. Detection limits between 50 and 150 fmol were achieved for unconjugated and acetylated polyamines. Of more than twenty drugs and amines tested for possible interference with the assay, only normetanephrine was found to have the same retention time as the internal standard 1,6-diaminohexane.

Cerebrospinal fluid polyamines: biochemical markers of malignant childhood brain tumors.

The clinical value of cerebrospinal fluid (CSF) polyamine determinations in childhood medulloblastoma has been suggested. We performed 72 CSF polyamine determinations in 35 children with primary brain tumors. Spermine values were normal and spermidine values were inconsistently elevated. CSF putrescine values, however, were consistently elevated in patients with histologically malignant brain tumors: medulloblastoma, ependymoma, pineal germ cell tumors, primitive neuroectodermal tumors, and brainstem gliomas. Children with supratentorial astrocytomas had normal CSF polyamine values. CSF putrescine values were closely correlated with clinical state, with the highest concentrations identified in patients with widely disseminated recurrent disease. We found CSF putrescine to be a sensitive indicator of active disease in childhood malignant brain tumors. Further investigation is warranted into the predictive value of CSF polyamines in determining tumor relapse before clinical or other diagnostic studies reveal recurrent disease.

Evaluation of polyamine levels in cerebrospinal fluid of children with brain tumors.

Cerebrospinal fluid (CSF) polyamine levels were analyzed retrospectively in 21 pediatric patients with different types of intracranial malignant tumors to determine the benefit of following these markers during the clinical management of brain tumors. The tumors included 16 medulloblastomas and 1 each of germinoma, ependymoma, primitive neuroectodermal tumor, astrocytoma, and malignant teratoma. The clinical course of each patient was followed by neurologic examination, cranial computed tomography, CSF cell count, and cytology after cytocentrifugation. The correlation of CSF putrescine and spermidine levels with the clinical course of the brain tumors was analyzed. The following results were obtained: (1) A significant increase in CSF putrescine levels was observed in children with medulloblastoma when there was recurrent or metastatic disease in the sites close to the CSF pathway compared with the children whose disease status was stable after successful treatment (P less than 0.005). (2) The increase of CSF putrescine levels was the earliest predictor of recurrence or metastasis near the CSF pathway. (3) In tumors other than medulloblastoma, the levels of polyamines were not predictive of disease activity with the possible exception of germinoma. (4) Spermidine levels in the CSF were of limited clinical importance for patients with brain tumors. CSF putrescine levels may be the earliest and most sensitive quantitative marker of the progression of medulloblastoma, and their evaluation should be included in the diagnostic work-up and follow-up examination of children with medulloblastoma.

Tumor markers and cytologic features of cerebrospinal fluid.

Tumor markers are useful in establishing the diagnosis of certain central nervous system tumors, especially germinal tumors of the pineal region. They are not sufficiently specific to be able to replace biopsy for exact diagnosis. They may also be useful for monitoring of therapy, as an indicator of recurrence of the tumor. Cerebrospinal fluid cytology is not generally useful in establishing a specific histologic diagnosis, especially in children, but can help to monitor therapy and predict tumor recurrence. More extensive studies are needed in both areas to define more precisely the role of markers and cytologic studies.

Assessment of tumor markers in cerebrospinal fluid.

In clinical practice, the examination of cerebrospinal fluid from patients with primary or metastatic brain tumors is commonly limited to cytomorphologic and routine chemistry analysis. The relative lack of sensitivity and specificity of these tests has led to a search for markers that can detect nervous system involvement by neoplasms at an earlier stage and even predict the site of origin of the neoplasms. This article summarizes recent investigators of biochemical tumor markers and cytoplasmic and cell surface markers in cerebrospinal fluid from patients with nervous system tumors.

Cerebrospinal fluid polyamines in childhood leukemia.

Cerebrospinal fluid (CSF) polyamines were measured in children with acute lymphocytic leukemia or non-Hodgkin's lymphoma in various stages of the disease ranging from complete remission to active central nervous system (CNS) involvement. Polyamines were analyzed by ion exchange chromatography with o- pthalaldehyde fluorimetric detection. Putrescine concentrations in random CSF samples obtained from leukemic patients with and without CNS involvement were not significantly different. Spermidine levels were generally higher in patients without CNS leukemia than in patients with the disease. In serial CSF specimens from an individual patient, spermidine levels correlated well with clinical status, being high in the active stages of the disease and low in remission. Thus, CSF polyamines appear to be of limited value as a screening test for early detection of CNS leukemia; however, they may offer an additional means of evaluating CNS leukemia and its response to therapy.

[Markers of brain tumors]. / I marker dei tumori cerebrali.

Biological markers of tumors are compounds or enzymatic activities measurable in body fluids. Their presence or concentration must be linked to tumoral growth. The markers of the central nervous system tumors are detected in CSF. Alpha-feto-protein, carcinoembryonic antigen, human chorionic gonadotropin, adenohypophyseal peptide hormones, enzymes, etc., have found some application in the early diagnosis of leptomeningeal metastasis. Other applications involve the early detection and recurrency of primary brain tumors, as well as the evaluation of efficacy of their therapy. The tests based on the CSF content of desmosterol and polyamines have been studied extensively. Their rationale is discussed and specificity, sensitivity, efficiency and predictive value are considered. Experimental results concerning a new possible biochemical marker, based on CSF concentration of cyclic adenosine monophosphate, are reported.

Polyamines in human brain tumors. A correlative study between tumor, cerebrospinal fluid and red blood cell free polyamine levels.

Polyamine levels have been studied in brain tumor patients. We focused our study on the relationship between tumor, cerebrospinal fluid (CSF) and red blood cell (RBC) polyamine levels. Our results are the following: Polyamine levels in CSF are consistently increased, whatever the histological type may be. The highest tumoral concentrations are found in medulloblastoma. In glioblastomas, the RBC spermidine levels are higher than in the other types of tumors and there is a highly significant correlation between the spermidine/spermine ratio in tumor and RBC. Therefore, RBC polyamine determination might be of clinical interest in the monitoring of patients with glioblastomas.

CSF polyamines in childhood.

Specimens of CSF from 76 children without neurologic disease and from 191 children with neurosurgical conditions were assayed for polyamine content. Putrescine and spermidine concentrations decreased with age. In children with intracranial tumors, polyamine concentrations in lumbar CSF were comparable with those in ventricular CSF. Putrescine level was significantly increased in children with medulloblastomas. Spermidine level was increased in children with medulloblastomas, glioblastomas, and astrocytomas. Concentrations of putrescine and spermidine were significantly increased in infants with myelomeningocele and hydrocephalus. Spermidine concentrations were significantly increased in older children with myelomeningocele, encephalocele, and hydrocephalus. Polyamines thus seem to be increased by rapid cell proliferation and by disorders affecting myelination. Since putrescine and spermidine concentrations may be of use in monitoring tumor progression, the effects of childhood growth and of hydrocephalus must be considered for children whose brain tumors are associated with hydrocephalus.

Polyamine levels in CSF from patients with pituitary tumors or nonneoplastic pituitary disease.

Cerebrospinal fluid polyamine determinations were performed in 21 patients harboring pituitary tumors and six patients with nonneoplastic pituitary disease. Although CSF putrescine levels were significantly elevated in some patients harboring tumors, other patients showed no elevation. Polyamine levels did not correlate with tumor size, as assessed by the presence or absence of suprasellar extension. Data on patients harboring nonneoplastic pituitary disease were variable. Compared with other findings from this laboratory on the use of polyamine levels for the diagnosis and management of other brain tumors, these findings suggest that CSF polyamine levels will not have a significant diagnostic role in the treatment of patients suspected to have pituitary disease.