Cancer radioresistance is characterized by a differential lipid droplet content along the cell cycle

BACKGROUND

Cancer radiation treatments have seen substantial advancements, yet the biomolecular mechanisms underlying cancer cell radioresistance continue to elude full understanding. The effectiveness of radiation on cancer is hindered by various factors, such as oxygen concentrations within tumors, cells' ability to repair DNA damage and metabolic changes. Moreover, the initial and radiation-induced cell cycle profiles can significantly influence radiotherapy responses as radiation sensitivity fluctuates across different cell cycle stages. Given this evidence and our prior studies establishing a correlation between cancer radiation resistance and an increased number of cytoplasmic Lipid Droplets (LDs), we investigated if LD accumulation was modulated along the cell cycle and if this correlated with differential radioresistance in lung and bladder cell lines.

RESULTS

Our findings identified the S phase as the most radioresistant cell cycle phase being characterized by an increase in LDs. Analysis of the expression of perilipin genes (a family of proteins involved in the LD structure and functions) throughout the cell cycle also uncovered a unique gene cell cycle pattern.

CONCLUSIONS

In summary, although these results require further molecular studies about the mechanisms of radioresistance, the findings presented here are the first evidence that LD accumulation could participate in cancer cells' ability to better survive X-Ray radiation when cells are in the S phase. LDs can represent new players in the radioresistance processes associated with cancer metabolism. This could open new therapeutic avenues in which the use of LD-interfering drugs might enhance cancer sensitivity to radiation.

oChanges in Radical Levels as a Cause for the FLASH effect: Impact of beam structure parameters at ultra-high dose rates on oxygen depletion in water

The influence of different average and bunch dose rates in electron beams on the FLASH effect was investigated. The present study measures O2 content in water at different beam pulse patterns and finds strong correlation with biological data, strengthening the hypothesis of radical-related mechanisms as a reason for the FLASH effect.

Does FLASH deplete oxygen? Experimental evaluation for photons, protons, and carbon ions

PURPOSE

To investigate experimentally, if FLASH irradiation depletes oxygen within water for different radiation types such as photons, protons, and carbon ions.

METHODS

This study presents measurements of the oxygen consumption in sealed, 3D-printed water phantoms during irradiation with x-rays, protons, and carbon ions at varying dose rates up to 340 Gy/s. The oxygen measurement was performed using an optical sensor allowing for noninvasive measurements.

RESULTS

Oxygen consumption in water only depends on dose, dose rate, and linear energy transfer (LET) of the irradiation. The total amount of oxygen depleted per 10 Gy was found to be 0.04% atm - 0.18% atm for 225 kV photons, 0.04% atm - 0.25% atm for 224 MeV protons, and 0.09% atm - 0.17% atm for carbon ions. Consumption depends on dose rate by an inverse power law and saturates for higher dose rates because of self-interactions of radicals. Higher dose rates yield lower oxygen consumption. No total depletion of oxygen was found for clinical doses.

CONCLUSIONS

FLASH irradiation does consume oxygen, but not enough to deplete all the oxygen present. For higher dose rates, less oxygen was consumed than at standard radiotherapy dose rates. No total depletion was found for any of the analyzed radiation types for 10 Gy dose delivery using FLASH.

The organisation of paediatric renal care in different European countries: results of the PAC project

The Paediatric Access Care (PAC) project, organised by the Research Board of EDTNA/ERCA, aimed to study the organisation of paediatric renal care in Europe and to investigate the practice of access care for both haemodialysis (HD) and peritoneal dialysis (PD) paediatric patients. This paper reports on the organisation of paediatric renal care. The majority of paediatric renal care units were located in specific paediatric units of university hospitals. Most of the centres had offered HD, PD and transplantation (Tx) for more than 20 years. Half of nursing staff had qualifications in paediatric and renal nursing. Most of the centres offered an extended multidisciplinary team approach with the family actively involved in the care of the patient. PD and HD were equally used. Automatic Peritoneal Dialysis (APD) was offered as the standard PD treatment in 2 out of 3 centres. The HD schedule mostly utilised was 3 x 4 hours a week. Half of the patients were on the Tx waiting list and one third of registered patients were transplanted in 2004.

Paediatric access care in Europe: results of the Paediatric Access Care (PAC) project

Part two of the Paediatric Access Care (PAC) project, a research project of EDTNA/ERCA, investigated PAC in HD and PD patients including the policy for the creation and maintenance of access, and the registration of access related complications that occurred during the registration year of 2004. Data were collected from 39 centres of 13 European countries and included 379 paediatric patients. Fatal complications, resulting in terminating the use of the access, were noted in 59 HD and 22 PD patients. Paediatric access care varied considerably between European centres and in many areas consensus or best practice evidence is still lacking. There is a need for recommendations for the paediatric renal nurse, handling access care in the paediatric renal population.

An HPLC tracing of the enhancer regulation in selected discrete brain areas of food-deprived rats

The recent discovery of the enhancer regulation in the mammalian brain brought a different perspective to the brain-organized realization of goal-oriented behavior, which is the quintessence of plastic behavioral descriptions such as drive or motivation. According to this new approach, 'drive' means that special endogenous enhancer substances enhance the impulse-propagation-mediated release of transmitters in a proper population of enhancer-sensitive neurons, and keep these neurons in the state of enhanced excitability until the goal is reached. However, to reach any goal needs the participation of the catecholaminergic machinery, the engine of the brain. We developed a method to detect the specific enhancer effect of synthetic enhancer substances [(-)-deprenyl, (-)-PPAP, (-)-BPAP] by measuring the release of transmitters from freshly isolated selected discrete brain areas (striatum, substantia nigra, tuberculum olfactorium, locus coeruleus, raphe) by the aid of HPLC with electrochemical detection. To test the validity of the working hypothesis that in any form of goal-seeking behavior the catecholaminergic and serotonergic neurons work on a higher activity level, we compared the amount of norepinephrine, dopamine, and serotonin released from selected discrete brain areas isolated from the brain of sated and food-deprived rats. Rats were deprived of food for 48 and 72 hours, respectively, and the state of excitability of their catecholaminergic and serotonergic neurons in comparison to that of sated rats was measured. We tested the orienting-searching reflex activity of the rats in a special open field, isolated thereafter selected discrete brain areas and measured the release of norepinephrine, dopamine, and serotonin from the proper tissue samples into the organ bath. The orienting-searching reflex activity of the rats increased proportionally to the time elapsed from the last feed and the amount of dopamine released from the striatum, substantia nigra and tuberculum olfactorium, that of norepinephrine released from the locus coeruleus and that of serotonin released from the raphe increased significantly in the hungry rats proportionally to the time of fasting. For example: the amount of dopamine released from the substantia nigra of sated rats (4.62 +/- 0.20 nmoles/g wet weight) increased to 5.95 +/- 0.37 (P < 0.05) and 10.67 +/- 0.44 (P < 0.01) in rats deprived of food for 48 and 72 hours, respectively.

Analysis of the effect of (-)-BPAP, a selective enhancer of the impulse propagation mediated release of catecholamines and serotonin in the brain

Endogenous and synthetic enhancer substances enhance in low concentration the impulse propagation mediated release of transmitters from the catecholaminergic and serotonergic neurons in the brain. The purpose of this study was to see whether uptake or MAO inhibition or agonists have similar enhancing prospectives as the enhancer substances. We measured the electrical stimulation induced release of [3H]-norepinephrine or [3H]-dopamine or [3H]-serotonin from the isolated brain stem of rats. (-)-1-Benzofuran-2-yl)-2-propylaminopentane HCl [(-)-BPAP] was used as a prototype of the enhancer compounds. 50 ng/ml (-)-BPAP was the most effective concentration in enhancing the nerve stimulation induced release of [3H]-norepinephrine and [3H]-dopamine, 10 ng/ml (-)-BPAP was highly effective in enhancing the release of [3H]-serotonin. In contrast, 250 ng/ml desmethylimipramine (DMI), a selective inhibitor of the uptake of norepinephrine, did not change significantly the nerve stimulation induced release of [3H]-norepinephrine and 50 ng/ml fluoxetine, a selective inhibitor of the uptake of serotonin, did not change the release of [3H]-serotonin. Neither 250 ng/ml clorgyline, a selective inhibitor of MAO-A, nor 250 ng/ml lazabemide, a selective inhibitor MAO-B, was capable to significantly increase the nerve stimulation induced release of either [3H]-serotonin or [3H]-norepinephrine. The potent dopamine receptor agonists, pergolide and bromocriptine did not change significantly the release of [3H]-dopamine in 50 ng/ml concentration, which is sufficient to stimulate the dopamine receptors. The results prove that stimulation of catecholaminergic and serotonergic neurons in the brain via the enhancing mechanism is clearly different from influencing uptake or MAO.

A pharmacological analysis elucidating why, in contrast to (-)-deprenyl (selegiline), alpha-tocopherol was ineffective in the DATATOP study

The Parkinson Study Group who conducted the Deprenyl and Tocopherol Antioxidative Therapy of Parkinsonism (DATATOP) trial designed their study in the belief that the MAO inhibitor (-)-deprenyl (selegiline), the antioxidant alpha-tocopherol, and the combination of the two compounds will slow the clinical progression of the disease to the extent that MAO activity and the formation of oxygen radicals contribute to the pathogenesis of nigral degeneration. In fact, (-)-deprenyl only delayed the onset of disability associated with early, otherwise untreated Parkinson's disease, however, in contrast to the expectation of the authors, alpha-tocopherol proved to be ineffective in the DATATOP study. Enhancer substances, (-)-deprenyl, (-)-1-phenyl-2-propylaminopentane [(-)-PPAP] the (-)-deprenyl analogue free of MAO inhibitory potency, and R-(-)1-(benzofuran-2-yl)-2-propylaminopentane [(-)-BPAP] the presently known most potent enhancer substance, are peculiar stimulants. They enhance the impulse propagation mediated release of the catecholamines in the brain. Due to their enhancer effect, the amount of catecholamines released from selected discrete brain areas (striatum, substantia nigra, tuberculum olfactorium, locus coeruleus) is significantly higher in rats treated with an enhancer substance than in saline treated rats. We compared the effect of (-)-deprenyl 0.025 and 0.25 mg/kg, (-)-PPAP 0.1 mg/kg, (-)-BPAP 0.0001 mg/kg, and alpha-tocopherol 25 and 50 mg/kg, in this test. The doses of (-)-deprenyl and alpha-tocopherol were selected to be in compliance with the dose given in the DATATOP study. Compared to saline treated rats, the enhancer substances significantly increased the amount of dopamine released from the striatum, substantia nigra and tuberculum olfactorium and the amount of norepinephrine released from the locus coeruleus; alpha-tocopherol was ineffective. The results indicate that alpha-tocopherol was ineffective, because, unlike (-)-deprenyl it dose not enhance the activity of the nigrostriatal dopaminergic neurons.

Undifferentiated embryonal sarcoma with unusual features arising within mesenchymal hamartoma of the liver: report of a case and review of the literature

Undifferentiated embryonal sarcoma (UES) is a rare and highly malignant hepatic neoplasm, affecting almost exclusively the pediatric population. It has replaced malignant mesenchymoma, under which diagnostic term the first three cases were described. A link between embryonal sarcoma and mesenchymal hamartoma of the liver (MHL) has long been proposed, because of clinicopathologic overlaps of these entities; however, until recently, this association remained tenuous. Cases of UES arising in a background of mesenchymal hamartoma of the liver have previously been reported in two teenage girls. Discovery of a similar genetic abnormality in MHL and UES has clinched the supposed link between them. There have also been two reports of UES with prominent cystification, one associated with peripheral eosinophilia, and thereby masquerading as hydatid cyst of the liver. We report a case of UES arising in a young boy with MHL, with unusual histologic features, including large mesothelial-lined cysts and ectopic adrenal cortical tissue under Glisson's capsule.

Antiaging compounds: (-)deprenyl (selegeline) and (-)1-(benzofuran-2-yl)-2-propylaminopentane, [(-)BPAP], a selective highly potent enhancer of the impulse propagation mediated release of catecholamine and serotonin in the brain

Hundreds of millions of people now die over the age of 80 years primarily due to twentieth century progress in hygiene, chemotherapy, and immunology. With a longer average lifespan, the need to improve quality of life during the latter decades is more compelling. "Aging--The Epidemic of the New Millenium," a recent international conference (Monte Carlo, June 17-18, 2000), showed with peculiar clarity that a safe and efficient drug strategy to slow the age-related decay of brain performance is still missing. This review summarizes the physiologic and pharmacologic arguments in favor of a peculiar lifelong prophylactic medication with reasonable chances to keep in check brain aging and decrease the precipitation of age-related neurological diseases.

(-)-1-(Benzofuran-2-yl)-2-propylaminopentane enhances locomotor activity in rats due to its ability to induce dopamine release

"Catecholaminergic and serotoninergic activity enhancer" effects are newly found mechanisms of action of a class of compound that enhance impulse propagation-mediated release of catecholamines and serotonin in the brain. In the present study, (-)-1-(benzofuran-2-yl)-2-propylaminopentane hydrochloride [(-)-BPAP HCl], a compound with selective and potent "catecholaminergic and serotoninergic activity enhancer" effects, was tested for its efficacy to potentiate locomotor activity in normal rats and to attenuate hypolocomotion in reserpine-treated rats. (-)-BPAP HCl potentiated locomotor activity in non-habituated rats during a 2-h observation period dose-dependently (0.3-10 mg/kg). (-)-BPAP HCl (1-3 mg/kg) was also effective to reverse reserpine-induced hypolocomotion. The effects of (-)-BPAP HCl in normal and reserpine-treated rats were attenuated by the dopamine D1 receptor antagonist, R(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine (SCH 23390), suggesting that the effects of (-)-BPAP HCl were mediated by activation of the dopaminergic system. In addition, the administration of (-)-BPAP HCl increased ipsilateral turning in unilaterally 6-hydroxydopamine-lesioned rats, implying presynaptic activation of nigrostriatal dopaminergic terminals by (-)-BPAP HCl. Furthermore, although antiparkinsonian agents, such as apomorphine and amantadine, failed to improve reserpine-induced ptosis, (-)-BPAP HCl significantly improved ptosis. These findings suggested that a "catecholaminergic and serotoninergic activity enhancer" compound, (-)-BPAP, stimulates motor function in rats and improves motor deficits in animal models of Parkinson's disease due to its ability to induce dopamine release.

Enantioselective synthesis and absolute configuration of (−)-1-(benzofuran-2-yl)-2-propylaminopentane, ((−)-BPAP), a highly potent and selective catecholaminergic activity enhancer

Enantioselective synthesis and absolute configuration of (-)-1-(benzofuran-2-yl)-2-propylaminopentane ((-)-BPAP), which is a highly potent and selective catecholaminergic activity enhancer (CAE) substance, are described. The synthetic approach consists of the coupling reaction of benzofuran with (R)-N-tosyl-2-propylazirizine or (R)-N-methoxy-N-methylnorvaliamide, followed by appropriate modifications of the resulting coupling products. As the results, (-)-BPAP turned out to have the R configuration, which was finally confirmed by X-ray crystallographic analysis.

Structure–activity studies leading to (−)1-(Benzofuran-2-yl)-2-propylaminopentane, ((−)BPAP), a highly potent, selective enhancer of the impulse propagation mediated release of Catecholamines and Serotonin in the brain

The catecholaminergic and serotoninergic neurons in the brain change their performance according to the physiological need via a catecholaminergic/serotoninergic activity enhancer (CAE/SAE) mechanism. Phenylethylamine (PEA), tyramine and tryptamine are the presently known endogenous CAE/SAE substances which enhance the impulse propagation mediated release of catecholamines and serotonin in the brain. A PEA derivative, (-)deprenyl (selegiline), known as a selective inhibitor of MAO-B, is for the time being the only CAE/SAE substance in clinical use. Aiming to develop a selective CAE/SAE substance much more potent than (-)deprenyl, a series of new 1-aryl-2-alkylaminoalkanes, structurally unrelated to PEA and the amphetamines, was designed and prepared. Among them, (-)1-(benzofuran-2-yl)-2-propylaminopentane ((-)BPAP) was selected as a promising candidate substance for further studies. (-)BPAP significantly enhanced in rats the impulse propagation mediated release of catecholamines and serotonin in the brain 30min after acute injection of 0.36nmol/kg sc. In the shuttle box, (-)BPAP was in rats about 130 times more potent than (-)deprenyl in antagonizing tetrabenazine induced inhibition of performance. (+/-)BPAP protected cultured hippocampal neurons from the neurotoxic effect of beta-amyloid in 10(-14)-10(-15)M concentration.

(-)Deprenyl (Selegiline): past, present and future

(-)Deprenyl (Selegiline), the N-propargyl analogue of (-)methamphetamine, is the only drug in clinical case which, by enhancing the impulse propagation mediated release of noradrenaline and dopamine in the brain (catecholaminergic activity enhancer, CAE, effect), keeps in small doses without side-effects the catecholaminergic brain system on a higher activity level. (-)Deprenyl stimulates the catecholaminergic neurons selectively in the brain because, in contrast to PEA and the amphetamines which induce the continuous release of noradrenaline and dopamine from their intraneuronal stores, (-)deprenyl is devoid of this property. It is due to the CAE effect that a) the maintenance of rats on (-)deprenyl during the postdevelopmental phase of their life slows the age-related decline of sexual and learning performances and prolongs life significantly; b) patients with early, untreated Parkinson's disease maintained on (-)deprenyl need levodopa significantly later than their placebo-treated peers, and when on levodopa plus (-)deprenyl, they live significantly longer than patients on levodopa alone; and c) in patients with moderately severe impairment from Alzheimer's disease, treatment with (-)deprenyl slows the progression of the disease. It is reasonable to expect that a prophylactic low dose administration of a safe catecholaminergic activity enhancer substance during the postdevelopmental phase of life will slow the age-related decline of behavioral performances, delay natural death and decrease susceptibility to Parkinson's disease and Alzheimer's disease.

Sexual hormones terminate in the rat: the significantly enhanced catecholaminergic/serotoninergic tone in the brain characteristic to the post-weaning period

The amount of dopamine released from the striatum, substantia nigra and tuberculum olfactorium, noradrenaline from locus coeruleus and serotonin from the raphe, was significantly higher in four and five weeks old rats than in three month old ones, proving that the catecholaminergic/serotoninergic activity enhancer (CAE/SAE) regulation works unrestrained during developmental longevity and is restricted thereafter. As the dampening of the CAE/SAE regulation (end to the second month of age) coincided temporally with the appearance of sexual hormones, we castrated three weeks old male and female rats and measured at the end of the third month of their life the release of catecholamines and serotonin from selected discrete brain regions. The amount of catecholamines and serotonin released from the neurons was significantly higher in castrated than in untreated or sham operated rats, signalting that sexual hormones inhibit the CAE/SAE regulation in the brain. We therefore treated male and female rats s.c. with oil (0.1 ml/rat), testosterone, (0.1 mg/rat), estrone (0.01 mg/rat) and progesterone (0.5 mg/rat), respectively, and measured their effect on the CAE/SAE regulation. Twenty-four hours after a single injection with the hormones, the release of noradrenaline, dopamine and serotonin was significantly inhibited in the testosterone or estrone treated rats, but remained unchanged after progesteron treatment. In rats treated with a single hormone injection, testosterone in the male and estrone in the female was the significantly more effective inhibitor. Remarkably, the reverse order of potency was found in rats treated with daily hormone injections for 7 or 14 days. After two-week treatment with the hormones estrone was in the male and testosterone in the female the significantly more potent inhibitor of the CAE/SAE regulation. The data indicate that sexual hormones terminate the hyperactive phase of adolescence by dampening the impulse propagation mediated release of catecholamines and serotonin in the brain.

(-)1-(Benzofuran-2-yl)-2-propylaminopentane, [(-)BPAP], a selective enhancer of the impulse propagation mediated release of catecholamines and serotonin in the brain

1. The brain constituents beta-phenylethylamine (PEA) and tryptamine enhance the impulse propagation mediated transmitter release (exocytosis) from the catecholaminergic and serotoninergic neurons in the brain ('catecholaminergic/serotoninergic activity enhancer, CAE/SAE, effect'). (-)Deprenyl (Selegiline) and (-)1-phenyl-2-propylaminopentane [(-)PPAP] are amphetamine derived CAE substances devoid of the catecholamine releasing property. 2. By changing the aromatic ring in PPAP we developed highly potent and selective CAE/SAE substances, structurally unrelated to the amphetamines. Out of 65 newly synthetized compounds, a tryptamine derived structure, (-)1-(benzofuran-2-yl)-2-propylaminopentane [(-)BPAP] was selected as a potential follower of (-)deprenyl in the clinic and as a reference compound for further analysis of the CAE/SAE mechanism in the mammalian brain. 3. (-)BPAP significantly enhanced in 0.18 micromol 1(-1) concentration the impulse propagation mediated release of [(3)H]-noradrenaline and [(3)H]-dopamine and in 36 nmol 1(-1) concentration the release of [(3)H]-serotonin from the isolated brain stem of rats. The amount of catecholamines and serotonin released from isolated discrete rat brain regions (dopamine from the striatum, substantia nigra and tuberculum olfactorium, noradrenaline from the locus coeruleus and serotonin from the raphe) enhanced significantly in the presence of 10(-12) - 10(-14) M (-)BPAP. BPAP protected cultured hippocampal neurons from the neurotoxic effect of beta-amyloid in 10(-14) M concentration. In rats (-)BPAP significantly enhanced the activity of the catecholaminergic and serotoninergic neurons in the brain 30 min after acute injection of 0.1 microg kg(-1) s.c. In the shuttle box, (-)BPAP in rats was about 130 times more potent than (-)deprenyl in antagonizing tetrabenazine induced inhibition of performance.

Clinical experience using gabapentin adjunctively in patients with a history of mania or hypomania

BACKGROUND

Gabapentin is an anticonvulsant proposed to have mood-stabilizing properties. It has been effective in the add-on treatment of refractory partial seizures and secondary generalized tonic-clonic seizures. It has the advantage of a favorable side effect profile and lack of drug interactions.

METHODS

Twelve consecutive outpatients with persistent, treatment-resistant bipolar spectrum disorders were treated with gabapentin in combination with other medications. Patients were started at 300 mg/day, which was titrated according to clinical response. Response was assessed every 3-4 weeks with a Clinical Global Improvement Scale. Dosage and side effects were noted. The median peak dose was 2400 mg/day.

RESULTS

One patient had a marked response to gabapentin; seven, a moderate response; two, mild; and two, no response to treatment. Six patients discontinued treatment due to somatic complaints (i.e., sedation or fatigue). The most frequently reported adverse effect was sedation.

LIMITATIONS

Gabapentin was added openly, and rating was nonblind in this case series. The use of concomitant medications could have increased the amount of sedation experienced with gabapentin.

CONCLUSION

Overall, gabapentin was associated with moderate improvement of mood symptoms. Given the severity and chronicity of these patients' illness, a moderate response must be considered a relative success. Controlled studies of gabapentin are needed to clarify its role in the treatment of bipolar disorder.

(-)Deprenyl (selegiline), a catecholaminergic activity enhancer (CAE) substance acting in the brain

beta-Phenylethylamine and its long acting derivatives, the amphetamines, are mixed-acting stimulants of the sympathetic system in the brain. They enhance the impulse propagation mediated release of catecholamines (catecholaminergic activity enhancer effect) and displace catecholamines from their stores (catecholamine releasing effect). (-)Deprenyl (selegiline), a close structural relative to (-)methamphetamine, is the first catecholaminergic activity enhancer substance in clinical use devoid of catecholamine releasing property, being therefore free of the 'cheese effect' and of the dependence capacity of the amphetamines. (-)Deprenyl is also a highly potent and selective, irreversible inhibitor of monoamine oxidase type B. (-)Deprenyl enhances superoxide dismutase and catalase activity in the striatum, protects the nigrostriatal dopaminergic neurons against selective neurotoxins (6-hydroxy-dopamine, MPTP, 4-N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine) and prevents characteristic age-related morphological changes in the neurocytes of the substantia nigra. Maintenance of rats on (-)deprenyl during the postdevelopmental phase of their life slows the age-related decline of sexual and learning performances and prolongs life significantly. Patients with early, untreated Parkinson's disease maintained on (-)deprenyl need levodopa significantly later than their placebo-treated peers, and when on levodopa plus (-)deprenyl, they live significantly longer than patients on levodopa alone. In patients with moderately severe impairment from Alzheimer's disease, treatment with (-)deprenyl slows the progression of the disease. It may be supposed that a prophylactic low dose administration of a safe catecholaminergic activity enhancer substance during the postdevelopmental phase of life will slow the age-related decline of behavioral performances, delay natural death and decrease susceptibility to Parkinson's disease and Alzheimer's disease.

[History of deprenyl--the first selective inhibitor of monoamine oxidase type B]

(-)Deprenyl (Selegiline, Jumex, Eldepryl, Movergan), a close structural relative of phenylethylamine (PEA), is a drug with a unique pharmacological spectrum. Whereas PEA and its long-lasting variants, the amphetamines, are mixed-acting stimulants of the sympathetic system in the brain, they primarily enhance the impulse propagation generated release of catecholamines (catecholamine activity enhancer, CAE, effect) and displace catecholamines in higher concentration (catecholamine releasing effect). (-)Deprenyl is the first CAE substance in clinical use devoid of catecholamine releasing activity. (-)Deprenyl is a highly potent and selective, irreversible inhibitor of B-type monoamine oxidase (MAO), a predominantly glial enzyme in the brain. The activity of this enzyme significantly increases with age. (-)Deprenyl, the first selective inhibitor of MAO-B described in the literature, has become a universally used research tool for selectively blocking B-type MAO and is still the only selective MAO-B inhibitor in world wide clinical use. In contrast to MAO inhibitors which strongly potentiate the catecholamine releasing effect of tyramine, (-)deprenyl inhibits it and is free of the 'cheese effect', which makes it a safe drug. Because its lack of the catecholamine releasing activity (-)deprenyl is devoid of amphetamine like dependence capacity. Maintenance on (-)deprenyl selectively enhances superoxide dismutase (SOD) and catalase activity in the striatum and protects the nigrostriatal dopaminergic neurons from selective neurotoxins (6-hydroxydopamine, MPTP, DSP-4). Maintenance of an animal on (-)deprenyl prevents the characteristic age-related morphological changes in the neuromelanin granules of the neurocytes in the substantia nigra. Many other protective effects of (-)deprenyl, denoted as 'neuroprotective', 'trophiclike neurorescue', 'apoptosis reducing', etc, have been described. All the protective actions of (-)deprenyl are thought to be primarily related to the CAE effect of the drug. All in all, (-)deprenyl increases the activity of the nigrostriatal dopaminergic system and slows its age-related decline. Maintenance of male rats on (-)deprenyl delays the age-related loss of their capacity to ejaculate, slows the age-related decline of their learning capacity and prolongs their life. Parkinsonian patients on levodopa plus (-)deprenyl (10 mg daily) live significantly longer than those on levodopa alone. Parkinsonian patients maintained, after diagnosis, on (-)deprenyl, need levodopa significantly later than their placebo-treated peers. Maintenance on (-)deprenyl significantly improves the performance of patients with Alzheimer's disease. It is concluded that patients developing Parkinson's or Alzheimer's disease need to be treated daily with 10 mg (-)deprenyl from diagnosis until death, irrespective of other medication. Because of the peculiar pharmacological spectrum and safety of the drug it may be advisable to combat the age-related decline of the nigrostriatal dopaminergic neurons in man by taking 10-15 mg (-)deprenyl weekly during the postdevelopmental phase of life. Prophylactic (-)deprenyl medication may improve the quality of life in the latter decades, delaying the time of natural death and decreasing the susceptibility to age-related neurological diseases.

Sexual performance and longevity

Sexually inactive ("low-performing," LP) and highly active ("high-performing," HP) rats were selected from a sexually inexperienced population. Saline control LP rats (n = 44) lived 134.58 +/- 2.29 weeks, their HP peers (n = 49) lived 151.24 +/- 1.36 weeks. Life-long treatment with 0.25 mg/kg (-)deprenyl, a selective inhibitor of MAO-B that also stimulates action potential-transmitter release coupling in the catecholaminergic neurons in the brain (catecholaminergic activity enhancer, CAE, effect), enhanced the sexual and learning performance of both LP and HP rats and prolonged their life. LP rats (n = 48) treated with (-)deprenyl lived 152.54 +/- 1.36 weeks and HP rats on (-)deprenyl (n = 50) lived 185.30 +/- 1.96 weeks. As an indicator of the basic activity of catecholaminergic neurons, the resting release of dopamine from the striatum, substantia nigra, and tuberculum olfactorium, and of norepinephrine from the locus coeruleus, was measured in 2-, 4-, 8-, 16-, and 32-week-old male and female rats. The release of transmitters between weaning and the second month of age, i.e., during the crucial developmental phase of life, was significantly higher than either before or after that period, indicating that a CAE mechanism starts working with high intensity after weaning, lasts until the completion of full scale sexual development, and shows an unparalleled decay thereafter. It was concluded that the CAE regulation in the brain, stimulated by (-)deprenyl, controls general activity and consequently the longevity of rats.

Phenylethylamine and tyramine are mixed-acting sympathomimetic amines in the brain

On the helical strip of a capacitance vessel, the pulmonary artery of the rabbit, phenylethylamine (PEA) and tyramine act solely via displacement of noradrenaline from their storage sites and this effect is inhibited by desmethylimipramine (DMI). In contrast, on a resistance vessel, the perfused central ear artery of the rabbit, PEA enhances stimulation induced contractions in 0.2-0.8 microgram/ml concentration [catecholaminergic activity enhancer (CAE) effect], and increases smooth muscle tone (noradrenaline displacing effect) in 4-6 micrograms/ml concentration. This latter effect only is blocked by DMI. Tyramine acts similarly and is more potent than PEA. On the isolated brain stem PEA, tyramine and (-)methamphetamine are, in the presence of cocaine and DMI, highly potent enhancers of stimulation induced release of 3H-noradrenaline, 3H-dopamine and 3H-serotonin. Compounds with specific CAE effect in the brain, (-)deprenyl and 1-phenyl-2-propylaminopentane [(-)PPAP], antagonize tetrabenazine-induced depression of performance of rats in the shuttle box. PEA and tyramine, which are rapidly metabolized in vivo, are ineffective in this test up to 40 mg/kg, whereas (-)methamphetamine, the stable PEA derivative, is highly effective. Compounds with CAE effect enhance at low concentrations the slow inward Ca2+ current in the sino-auricular fibers of the frog heart and inhibit it in high concentration. PEA and tyramine enhance Ca2+ influx from 0.05 to 4 micrograms/ml and inhibit it in 8 micrograms/ml. In conclusion, PEA and tyramine stimulate primarily coupling of action potential to transmitter release in the catecholaminergic neurons in the brain and displace catecholamines in higher concentration only.

(-)Deprenyl and (-)1-phenyl-2-propylaminopentane, [(-)PPAP], act primarily as potent stimulants of action potential-transmitter release coupling in the catecholaminergic neurons

The activity of the catecholaminergic neurons in the rat brain is enhanced significantly 30 min after the subcutaneous injection of very small doses of (-)deprenyl (threshold doses: 0.01 mg/kg for noradrenergic neurons and 0.025 mg/kg for dopaminergic neurons). As a catecholaminergic activity enhancer (CAE) substance (-)deprenyl is about ten times more potent than its parent compound, (-)methamphetamine. While the (+)methamphetamine is 3-5 times more potent than (-)methamphetammine in releasing catecholamines, the (-)methamphetamine is the more potent CAE substance. The mechanism of the CAE effect of (-)deprenyl and (-)PPAP, a deprenyl-derived substance devoid of MAO inhibitory potency, was studied in rats by measuring: a) the release of catecholamines from striatum, substantia nigra, tuberculum olfactorium and locus coeruleus; b) the stimulation induced release of 3H-noradrenaline from the isolated brain stem; and c) the antagonistic effect against tetrabenazine-induced depression of learning in the shuttle box. The CAE effect was found to be unrelated: a) to the inhibition of MAO activity; b) to the inhibition of presynaptic catecholamine receptors; c) to the inhibition of the uptake of catecholamines; and d) to the release of catecholamines. It was concluded that (-)deprenyl and (-)PPAP act primarily as potent stimulants of action potential-transmitter release coupling in the catecholaminergic neurons of the brain. We show that both (-)deprenyl and (-)PPAP enhance the inward Ca2+ current in sino-auricular fibers of the frog heart. (-)PPAP was much more potent than either (+)PPAP or (-)deprenyl in this test.

High performing rats are more sensitive toward catecholaminergic activity enhancer (CAE) compounds than their low performing peers

Two breeds of rats, Charles River Wistar [Crl(Wi)Br.] and HSD Wistar [Wistar per LATI (Budapest) Br.], with remarkable difference in learning performance were selected. The rats were trained in the shuttle box with 100 trials per day and the number of conditioned avoidance responses (CARs), the escape failures (EFs) to the unconditioned stimulus and the intersignal reactions (IRs) were counted and evaluated by multi-way analysis of variance (ANOVA). Rats of the Crl (Wi) breed proved to be the 'low performing' (LP) animals and rats of the Wistar per LATI (Budapest) breed the 'high performing' (HP) ones. The HP rats produced higher number of CARs (p<0.001), lower number of EFs (P<0.05) and higher number of IRs (P<0.01) than their LP peers. Significantly higher amounts of noradrenaline from the locus coeruleus and serotonin from the raphe were released in the HP than in the LP rats (p<0.01). There was no difference between HP and LP rats in the amount of dopamine released from the striatum, the substantia nigra and the tuberculum olfactorium. The catecholaminergic activity enhancer (CAE) substance, 1-phenyl-2-propylaminopentane HCl, [(-)PPAP], which enhances action potential-transmitter release coupling in the catecholaminergic neurons, fully antagonized in a dose of 1 mg/kg, tetrabenazine-induced learning depression in HP rats and this dose was ineffective in LP rats. The findings were regarded as further support for the view that endogenous CAE substances regulate catecholaminergic activity in the brain and (-)PPAP acts via this regulation.

Periventricular heterotopia: an X-linked dominant epilepsy locus causing aberrant cerebral cortical development

Periventricular heterotopia (PH) involves dramatic malformations of the human cerebral cortex. Here we show that PH is closely linked to markers in distal Xq28 (maximal two-point lod score = 4.77 for F8C at theta = 0; maximal multipoint lod score = 5.37), so that affected females are obligatory mosaics for the mutation; that PH is lethal to at least some affected males; that PH malformations consist of well-differentiated cortical neurons filling the adult subependymal zone; and that individuals with PH are at high risk for epilepsy, though they have no other neurological or external stigmata. The PH gene may represent an important epilepsy susceptibility locus in addition to playing a key role in normal cortical development.

Plasma adrenocorticotropin concentration in healthy horses and in horses with clinical signs of hyperadrenocorticism

Pituitary adenomas are commonly reported in older horses. The typical clinical signs associated with this condition, also known as equine Cushing's disease (ECD), are related to increased adrenocorticotropin (ACTH) production resulting in hyperadrenocorticism. The primary purpose of this study was to determine whether plasma ACTH concentrations differed between cushingoid and healthy horses. The second objective was to determine the effects of blood sample handling techniques on ACTH concentrations. A commercial human ACTH radioimmunoassay (RIA) was used to quantify equine plasma ACTH. Intra-assay and interassay variations, as well as dilutional parallelism were determined during the RIA validation. Plasma ACTH concentrations were evaluated in a group of healthy equids composed of 18 horses and 9 ponies, and in 22 equids with a clinical diagnosis of hyperadrenocorticism (11 horses and 11 ponies). The mean plasma ACTH concentrations in healthy horses and ponies, (18.68 +/- 6.79 pg/mL (mean +/- SD) and 8.35 +/- 2.92 pg/mL, respectively), were significantly different (P = .009). The mean plasma ACTH concentration in horses and ponies with ECD, (199.18 +/- 182.82 pg/mL and 206.21 +/- 319.56 pg/mL, respectively), were significantly higher than the mean ACTH concentration in the control animals (P < .001). Plasma ACTH concentrations appeared to be a sensitive and specific indicator of ECD in horses and ponies. ACTH concentrations measured in plasma samples kept at room temperature (19 degrees C) as long as 3 hours after blood collection were not statistically different from those of samples kept at 1 degree C.

cDNA sequence, genomic organization, and evolutionary conservation of a novel gene from the WAGR region

A new gene (239FB) with predominant and differential expression in fetal brain has recently been isolated from a chromosome 11p13-p14 boundary area near FSHB. The corresponding mRNA has an open reading frame of 294 amino acids, a 3' untranslated region of 1247 nucleotides, and a highly GC-rich 5' untranslated region. The coding and 3' UT sequence is specified by 6 exons within nearly 87 kb of isolated genomic locus. The 5' end region of the transcript maps adjacent to the only genomically defined CpG island in a chromosomal subregion that may be associated with part of the mental retardation of some WAGR (Wilms tumor, aniridia, genitourinary anomalies, and mental retardation) syndrome patients. In addition to nucleotide and amino acid similarity to an EST from a normalized infant brain cDNA library, the predicted protein has extensive similarity to two Caenorhabditis elegans polypeptides of, as yet, unknown function. The 239FB locus is, therefore, likely part of a family of genes with two members expressed in human brain. The extensive conservation of the predicted protein suggests a fundamental function of the gene product and will enable evaluation of the role of the 239FB gene in neurogenesis in model organisms.

Enhanced catecholaminergic and serotoninergic activity in rat brain from weaning to sexual maturity: rationale for prophylactic (-)deprenyl (selegiline) medication

Food deprived rats in the late developmental phase of life (2 months of age) are significantly more active than those in the early postdevelopmental phase (4 months of age), pointing to enhanced catecholaminergic activity during the developmental phase. We therefore measured the resting release of dopamine from the striatum, substantia nigra and tuberculum olfactorium, and of noradrenaline from the locus coeruleus, as an indicator of the basic activity of catecholaminergic neurons in the brain, in 2,4,8,16 and 32 weeks old male and female rats. We also measured the release of serotonin from the raphe. Both in male and female rats, the resting release of transmitters from brain catecholaminergic and serotoninergic neurons between weaning and the end of the 2nd month of age, i.e. during the crucial developmental phase of their life, was significantly higher than either before or after that period, signalling a transition from a developmental to a postdevelopmental (aging) phase of life and indicating that safe and effective measures are needed to maintain the catecholaminergic system at a higher activity level during the postdevelopmental phase. Daily administration of low doses (0.01-0.25 mg/kg) of (-)deprenyl for 21 days significantly enhances the resting release of catecholamines and diminishes that of serotonin, providing a rationale for prophylactic medication with this drug during the postdevelopmental lifespan. We also show that (-)methamphetamine, the parent compound of (-)deprenyl and (-)1-phenyl-2-propylaminopentane (PPAP), a deprenyl analogue free of MAO-B inhibitory potency but otherwise possessing the same pharmacological profile as (-)deprenyl, act similarly, furnishing direct evidence that enhancement of catecholaminergic activity in the brain by multiple, small dose administration of (-)deprenyl is unrelated to MAO-B inhibition.

Responses of forebrain neurons to the MAO-B blocker L-deprenyl

Despite the large amount of neuropharmacological data concerning catecholamine (CA) mechanisms of the mammalian brain, little is known yet about the effects of MAO-inhibitors on single neurons. The present series of experiments aim to elucidate these specific neurochemical attributes of forebrain cells. Single neuron activity was recorded by means of multi-barreled microelectrodes in the caudate nucleus, globus pallidus, and amygdala of both anesthetized rats and anesthetized or alert monkeys during microelectrophoretic application of the MAO-B blocker L-deprenyl (DEPR). CAs (dopamine and noradrenaline), glutamate, GABA, and acetylcholine were also applied. Nearly the half (46%) of all forebrain neurons tested responded, exclusively with inhibition, to DEPR, and the CA-sensitive cells were especially responsive to the MAO-B inhibitor. The time course of DEPR-induced neuronal suppression was short. In some cases, amphetamine (AMPH) and clorgyline (CLOR) were also applied microelectrophoretically. AMPH elicited similar activity changes to those seen after DEPR administrations, whereas CLOR applications were less effective. Our results provide evidence that DEPR can effectively modulate the activity of CA-sensitive neurons in the three different forebrain regions of two different species. On the basis of this data, the possible neurochemical mechanisms of DEPR action are discussed.

Rationale for (-)deprenyl (selegiline) medication in Parkinson's disease and in prevention of age-related nigral changes

(-)Deprenyl (selegiline, jumex, eldepryl, movergan), a close structural relative to phenylethylamine (PEA), is a drug with a unique pharmacological spectrum. It is a highly potent and selective, irreversible inhibitor of B-type monoamine oxidase (MAO), a predominantly glial enzyme in the brain. The activity of this enzyme significantly increases with age. (-)deprenyl, the first selective inhibitor of MAO-B described in literature, has become the universally used research tool for selectively blocking B-type MAO. It is the only selective MAO-B inhibitor in clinical use. (-)Deprenyl interferes with the uptake of catecholamines and indirectly acting sympathomimetics because it is handled by the catecholaminergic neuron in a way similar to the physiological substances transported through the axonal end organ and vesicular membrane. The unique behavior of (-)deprenyl is that, in striking contrast to PEA and its relatives it does not displace the transmitter from storage, ie it is not a releaser. The net result is that (-)deprenyl inhibits the releasing effect of tyramine, and at present, is the only safe MAO inhibitor that can be administered without dietary precautions. Maintenance on (-)deprenyl selectively enhances superoxide dismutase (SOD) and catalase activity in the striatum. This effect is unrelated to its effect on MAO-B and the inhibitory effects of the drug on neurotransmitter uptake. Maintenance on (-)deprenyl facilitates the activity of the catecholaminergic system in the brain, and this effect, too, is unrelated to either its effects on MAO or on neurotransmitter uptake. (-)Deprenyl protects the nigrostriatal dopaminergic neurons against selective neurotoxins (6-hydroxydopamine, MPTP, DSP-4).(ABSTRACT TRUNCATED AT 250 WORDS)

Multiple, small dose administration of (-)deprenyl enhances catecholaminergic activity and diminishes serotoninergic activity in the brain and these effects are unrelated to MAO-B inhibition

As a measure of the basic activity of the catecholaminergic and serotoninergic systems, the biogenic amines released from freshly excised brain tissue were measured by means of HPLC with electrochemical detection. Rats of both sexes were injected subcutaneously, daily for 21 days, either with saline or with a dose of one of the enantiomers of the following compounds: deprenyl; p-fluorodeprenyl; 1-phenyl-2-propylaminopentane, a deprenyl analogue free of MAO-B inhibitory potency; methamphetamine, the parent compound of deprenyl; and amphetamine, the parent compound of 1-phenyl-2-propylaminopentane. The release of the biogenic amines from brain tissue was measured 24 hours after the last injection. The effect of the two enantiomers of deprenyl was studied in five doses (0.01, 0.025, 0.05, 0.1 and 0.25 mg/kg), that of (-)1-phenyl-2-propylaminopentane in two doses (0.05 and 0.1 mg/kg), others in 0.05 mg/kg. Treatment with (-)deprenyl enhanced the release of dopamine from striatum, substantia nigra and tuberculum olfactorium (significant in 0.01-0.25 mg/kg) and the release of noradrenaline from the locus coeruleus (significant in 0.05-0.25 mg/kg), whilst the release of serotonin from the raphe was diminished (significant in 0.05-0.25 mg/kg in males and 0.25 mg/kg in females). (+)Deprenyl was slightly less potent than (-)deprenyl. Both p-fluorodeprenyl and 1-phenyl-2-propylaminopentane acted like deprenyl; the (+)enantiomers were more active than the (-)forms. (-)Methamphetamine was as potent as (-)deprenyl in enhancing the catecholaminergic activity and more potent than (-)deprenyl in diminishing the serotoninergic activity. (+)Methamphetamine was substantially less potent than (-)methamphetamine. (-)Amphetamine was as potent as (-)methamphetamine and (+)amphetamine was more potent than (+)methamphetamine in enhancing the catecholaminergic activity but neither (-)amphetamine nor (+)amphetamine diminished the serotoninergic activity. On the one hand, the results prove that the described effects of deprenyl are unrelated to MAO-B inhibition, on the other hand, they indicate the existence of hitherto unknown catecholaminergic and serotoninergic activity enhancer mechanisms in the brain, of which the former is stimulated and the latter inhibited by multiple, small dose administrations of deprenyl and related substances.