Distribution and levels of dopamine and its metabolites in brains of reproductive workers in honeybees

To explore the role of dopamine and its metabolites for change of reproductive states of workers in honeybees (Apis mellifera), brain levels of dopamine relative substances were measured and localized in both normal workers and queenless workers. Dopamine and two possible metabolites of dopamine, N-acetyldopamine (NADA) and norepinephrine were detected in brain extracts. The brain levels of dopamine, NADA and norepinephrine were positively correlated with ovary development. Individuals with high dopamine levels had high levels of NADA or norepinephrine, suggesting that these metabolites might be involved in the change of reproductive sates of workers. Dopamine was distributed mainly in the protocerebrum, whereas NADA was in both the optic lobes and the protocerebrum. Dopamine levels in each distinct brain regions were higher in queenless workers than in normal workers, whereas there was a higher NADA level in the optic lobes in queenless workers than in normal workers. These results suggest that dopamine might be stored and/or released around the protocerebrum and the deutocerebrum, and also diffuse to the optic lobes where dopamine secretory cells are absent, resulting in high NADA levels in the optic lobes. The different manner of level changes of dopamine and its metabolites in each brain region might cause compound behavioural modulations in reproductive workers.     

Biogenic amine binding sites in rabbit spermatozoa

The binding of the neuroleptic, [3H] spiperone, to rabbit spermatozoa was investigated. Binding was partially inhibited by haloperidol, mianserin or epinephrine. Mixtures of two of the three inhibitors reduced binding further, but binding of the radioligand to spermatozoa was lowest in the presence of all three inhibitors. Unlabeled spiperone eliminated binding. Cholinergic ligands, GABA, and beta-adrenergic ligands, had little effect on binding. Spiperone binding occurred to both heads and tails suggesting that alpha 1-adrenergic, D2-dopamine and S2-serotonin binding sites are present in the head and/or tail of rabbit spermatozoa.     

Biogenic amine hypotheses of affective disorders.

Many lines of evidence suggest that effective disease is a heterogenous group of disorders. Pharmacologic, amine metabolite and neuroendocrine studies have aided in the tentative identification of two subtypes of depressive illness. One subtype may show an abnormality of central NE systems; the other, an abnormality of central 5-HT systems. Manic patients appear to manifest abnormalities of multiple systems biologically which may be related to a disturbance of ion exchange in a variety of cells both within and outside of the CNS. The understanding of these processes is far from complete and are the subject of continued scrutiny.     

Exposure to static electric fields leads to changes in biogenic amine levels in the brains of Drosophila

Natural and anthropogenic static electric fields are commonly found in the environment and can have both beneficial and harmful effects on many animals. Here, we asked how the fruitfly responds to these fields and what the consequences of exposure are on the levels of biogenic amines in the brain. When given a choice in a Y-tube bioassay Drosophila avoided electric fields, and the greater the field strength the more likely Drosophila were to avoid it. By comparing wild-type flies, flies with wings surgically removed and vestigial winged flies we found that the presence of intact wings was necessary to produce avoidance behaviour. We also show that Coulomb forces produced by electric fields physically lift excised wings, with the smaller wings of males being raised by lower field strengths than larger female wings. An analysis of neurochemical changes in the brains showed that a suite of changes in biogenic amine levels occurs following chronic exposure. Taken together we conclude that physical movements of the wings are used by Drosophila in generating avoidance behaviour and are accompanied by changes in the levels of amines in the brain, which in turn impact on behaviour.     

Novel insect picorna-like virus identified in the brains of aggressive worker honeybees

To identify candidate genes involved in the aggressive behavior of worker honeybees, we used the differential display method to search for RNAs exclusively detected in the brains of aggressive workers that had attacked a hornet. We identified a novel, 10,152-nucleotide RNA, termed Kakugo RNA. Kakugo RNA encodes a protein of 2,893 amino acid residues that shares structural features and sequence similarities with various picorna-like virus polyproteins, especially those from sacbrood virus, which infects honeybees. The Kakugo protein contains several domains that correspond to the virion protein, helicase, protease, and RNA-dependent RNA polymerase domains of various picorna-like virus polyproteins. When the worker bee tissue lysate was subjected to sucrose density gradient centrifugation, Kakugo RNA, except for the material at the bottom, was separated into two major peaks. One of the peaks corresponded to the position of Kakugo mRNA, and the other corresponded to the position of the poliovirus virion. These results suggest that the Kakugo RNA exists as an mRNA-like free RNA and virion RNA in the honeybee. Furthermore, injection of the lysate supernatant from the attacker heads into the heads of noninfected bees resulted in a marked increase in Kakugo RNA. These results demonstrate that Kakugo RNA is a plus-strand RNA of a novel picorna-like virus and that the brains of aggressive workers are infected by this novel virus. Kakugo RNA was detected in aggressive workers but not in nurse bees or foragers. In aggressive workers, Kakugo RNA was detected in the brain but not in the thorax or abdomen, indicating a close relation between viral infection in the brain and aggressive worker behaviors.     

Biogenic amine content of rat gastric tissues during reduced gastric circulation

The content of biogenic amines in gastric tissues was studied in rats with celiac trunk stenosis 3 hours, one day, 2 and 7 days after operation. Chronic ischemia of the gastric wall was found to lead to the development of dystrophic changes in the gastric mucosa, accompanied by the decreased catecholamine content and elevated levels of histamine and serotonin.     

Biogenic amine uptake by nerve cords from the American cockroach and the influence of amidines on amine uptake and release

Uptake of 5-hydroxytryptamine (5-HT) by isolated whole nerve cords of the American cockroach, Periplaneta americana (L.), involved a dual component system, with one component consisting of rapid active uptake and the other of passive diffusion. Using high performance liquid chromatography with electrochemical detection, it was shown that nerve cords contained 5-HT levels of about 350 ng/g and an equivalent amount of 5-hydroxyindoleacetic acid (5-HIAA), a 5-HT metabolite not previously reported in cockroach nerve cords. Amidines had no discernable effect on uptake of 5-HT or octopamine by nerve cords or on endogenous levels of 5-HT and 5-HIAA in cords.     

Biogenic amine metabolites in human lung tumor cells: histochemical and mass-spectrographic demonstration

Three continuous cell lines isolated from small cell carcinoma of the lung (SCCL) have been examined for their ability to take up and metabolize the biogenic amine precursors, L-DOPA and 5-hydroxytryptophane (5-HTP). In two of the three lines formaldehyde-induced fluorescence (FIF) and mass-spectrographic analysis indicated specific uptake and metabolism of L-DOPA and 5-HTP.     

Pituitary serotonin: Responsiveness of levels to hormonal change and ultrastructural alterations associated with amine depletion

Summary The level of serotonin in the pituitary gland of young dogs was significantly increased following treatment with thyroxine and after the injection of reserpine. Electron microscopic examination of the pituitary gland of thyroxine treated animals failed to reveal any ultrastructural alterations. Treatment with reserpine induced the appearance of annulate lamellae in the cytoplasm of cells containing very small granules and having the morphology of thyrotrophs. These observations suggest that biogenic amines within the gland may be involved in regulating the cellular activity of the pituitary.Supported by NIH Grants AM 19743, NS 12969 and HD 10665The authors wish to thank John Patrikes and Helen Mantulin for their expert technical assistance     

Increased levels of superoxide in brains from old female rats

Hypertension, aging and a range of neurodegenerative diseases are associated with increased oxidative damage. The present study examined whether superoxide (O₂^•-) levels in brain are increased during aging in female rats, and the role of superoxide dismutase (SOD) and oestrogen in regulating O₂^•- levels.

Young adult (3 month) and old (11 month) female spontaneously hypertensive stroke prone rats (SHRSP) and normotensive Wistar-Kyoto rats (WKY) were studied. O₂^•- levels were measured in brain homogenates by lucigenin chemiluminescence and SOD expression by Western blotting. Ageing significantly increased brain O₂^•- levels in WKY (cortex +216%, hippocampus +320%, striatum +225%) and to a greater extent in SHRSP (cortex +540%, hippocampus +580%, striatum +533%). Older SHRSP showed a decline in cortical Cu/Zn SOD expression compared to young adult SHRSP. Oestrogen did not attenuate O₂^•- levels.

The results show a significant age-dependent increase in brain O₂^•- levels which is exaggerated in SHRSP. The excess cortical O₂^•- levels in the SHRSP may be associated with a down-regulation of Cu/Zn SOD but are not related to a decrease in oestrogen.     

Determination of pyridoxal phosphate levels in the brains of audiogenic and normal mice

The concentrations of pyridoxal-5-phosphate in the brains of audiogenic and normal mice were measured fluorimetrically. The brain of the audiogenic mouse (DBA/2J) contains 25% more pyridoxal-5-phosphate than the brain of a control mouse. Intraperitoneal injection of this substance causes a transient increase of its concentration in the brain, lasting a few hours. The substance thereafter is degraded to pyridoxal and pyridoxic acid.     

Cyclic nucleotide levels in brains of control and hypertensive rats.

Adenosine 3′, 5′-monophosphate (cyclic AMP) and guanosine 3′,5- monophosphate (cyclic GMP) levels were measured in seven brain areas of spontaneously hypertensive rats (SHR) and two groups of control rats. In cerebral cortex, hypothalamus, pons-medulla oblongata and cerebellum cyclic AMP levels were higher in SHR than in Wistar-Kyoto controls. Cyclic GMP levels were higher in SHR than in Wistar-Kyoto rats in all brain areas except for the striatum and hippocampus where the levels were lower. There were also some differences in cyclic nucleotide levels between Wistar-Kyoto and Wistar-Charles River controls.     

Increase in phospholipase C-delta1 protein levels in aluminum-treated rat brains

The effect of administration of aluminum to rats on the level of three phospholipase C (PLC) isozymes (beta1, gamma1, and delta1) was assessed in a variety of brain tissues. After exposure to aluminum, a statistically significant increase in malondialdehyde, an index of lipid peroxidation, was observed. In addition, there was a significant reduction in the catalytic activity of low molecular weight phosphotyrosine phosphatase, which loses its activity during oxidative stress. This suggests that oxidative stress is induced in brain tissues exposed to aluminum. The protein level of PLC-delta1, but not that of PLC-beta1 or -gamma1, was significantly increased in brains where oxidative stress had been induced. The total PLC activity in aluminum-treated rat brains was significantly higher than that in control brains. These results suggest that PLC-delta1 protein levels in brain tissues are increased by the induction of oxidative stress, giving an explanation for its up-regulation in Alzheimer's disease.     

Changes in the regional brain histamine and histidine levels in postmortem brains of Alzheimer patients

In postmortem brains of Alzheimer patients, statistically significant decreases in histamine levels were observed in the frontal (45%), temporal (20%), and occipital cortices (38%) and in the caudate nucleus (25%). Histidine levels were decreased in the frontal (15%), temporal (21%), and occipital cortices (30%) and in the caudate nucleus (25%); the decrease was statistically significant in the last two brain regions. Histamine was determined by the double isotope technique, and histidine was determined fluorometrically by a fluorescamine method. The data indicate that brain histamine regulation is altered in Alzheimer's disease.     

Blood gas and catecholamine levels in capture stressed desert bighorn sheep.

Forty-seven bighorn sheep (Ovis canadensis nelsoni) were captured within a 3-day period in December, 1989 as part of a California Department of Fish and Game effort to repopulate historic ranges in California. They were captured on the Mojave Desert in the Kelso Mountains near Old Dad Peak, San Bernardino County, California. Venous blood gases measured at the site of capture demonstrated a severe metabolic acidosis (base deficit, 23 mEq/liter), with no evidence of respiratory acidosis. There were moderately elevated plasma epinephrine (1.25 ng/ml), norepinephrine (2.60 ng/ml), and dopamine (114 pg/ml) levels. These data appear to reflect animals that have been moderately stressed. These acid-base-catecholamine values differ from values in resting domestic sheep, and are similar to those reported in greyhounds after brief strenuous exercise.