Involvement Of Biogenic Amines Research Articles

The neuropharmacological profile of interval responding during operant tasks.

Responses occurring during intervals of operant tasks have been subdivided as interim, facultative, and terminal, depending on the time between response onset and reward. Although interval responses, also known as adjunctive responses, have been described in pigeons, rats, mice, monkeys, and humans, most experiments have been conducted in rats. We review the neurochemical basis of interval responses and examine the hypothesis that these responses modulate operant performance. Preliminary experiments indicate the involvement of biogenic amines, acetylcholine, and GABA during interval responding associated with operant tasks. In particular, catecholaminergic deafferentation of the basal ganglia modulated interval responses as did the peripheral injection of catecholamine reuptake blockers. Under the influence of amphetamine, interval responding may either increase or decrease, so that a wide range of responses must be selected to gauge drug effects. In non-drugged pigeons and rats, the expression of interval responses facilitates operant training.

The Effect of Insecticidal Stress on Reproductive Output of Susceptible and Field Strains of Aedes aegypti (Diptera: Culicidae).

The phenomenon of high egg reproduction when mortality risk rises is common in mosquitoes. However, the phenomenon may vary between insecticide susceptible and field-collected strains, due to the latter's decreased energy allocation in reproduction in the presence of insecticide resistance. In this study, we evaluated the effect of chlorpyrifos (CP) and temephos (TP) exposure on the oviposition and survival of Aedes aegypti (Linnaeus) (Diptera: Culicidae) using a susceptible strain (KHsm) and two field strains (KHly and TNnorth). We also dissected the female mosquitoes of each strain on fifth day after the first blood meal to examine the total number of eggs produced. Neither CP nor TP exhibited oviposition deterrent against female mosquitoes of any of the three strains, as the females did not show decreased reproduction activity on the insecticide-treated sites. Of the two insecticides tested, only CP had an adulticidal effect on Ae. aegypti. High mortality was recorded in KHsm after contacting the CP-treated oviposition sites on day 4. Before death, KHsm mosquitoes oviposited significantly more eggs compared to the two field strains. However, the difference of total egg production between susceptible and field-collected strains was subtle. Thus, the decreased reproductive output in field-collected strains might not be directly linked to energy and resource allocation. In this respect, we should consider the possible involvement of biogenic amines in the egg retention in field-collected strains when mortality risk rises. The phenomenon was not observed in nonadulticidal TP treatment.

Changes in dopamine, norepinephrine and serotonin levels in the pituitary, telencephalon and hypothalamus during gonadal development of male Lutjanus argentiventris (Teleostei)

Biogenic amines are important in the regulation of certain aspects of teleost reproduction, but relatively little is known about variations in their levels in the nervous system during the reproductive cycle. The aim of this study was to investigate changes in the levels of dopamine (DA), norepinephrine (NE), serotonin (5-HT), the DA metabolite 3,4-dihydroxyphenylacetic acid (DOPAC) and the 5-HT metabolite 5-hydroxyindoleacetic acid (5-HIAA) in the pituitary and brain (hypothalamus and telencephalon) of the adult male of the tropical marine yellow snapper Lutjanus argentiventris during the reproductive cycle (quiescent, prespawning and spawning periods). Gonad weight, gonad/body weight ratio and plasma-testosterone levels increased steadily throughout gonadal development, but 17β-estradiol levels did not vary significantly. Pituitary DA and DOPAC levels and the DOPAC/DA ratio declined with gonadal development, whereas hypothalamic DOPAC level and DOPAC/DA ratio increased. In the telencephalon, DA and DOPAC levels and DOPAC/DA ratio all peaked in the prespawning period; however, DA level was lowest in the spawning period, whereas DOPAC level and DOPAC/DA ratio were both lowest in the quiescent period. Telencephalic NE, 5-HT and 5-HIAA levels likewise all peaked in the prespawning period, and were lowest in the spawning period. Telencephalic 5-HIAA/5-HT ratio peaked in the quiescent period and was lowest in the spawning period. No significant variation was observed either in pituitary NE level or in hypothalamic NE, 5-HT and 5-HIAA levels. The present results indicate that males of L. argentiventris show a decline in pituitary DA activity during gonadal development. We discuss the possible involvement of biogenic amines in the regulation of GTH II secretion, through direct action on the pituitary or indirect modulation of gonadotrophin-releasing hormone neuron activity.

Hyperglycemic responses to cold shock in the freshwater giant prawn, Macrobrachium rosenbergii

Crustacean hyperglycemic hormone (CHH), a neurohormone synthesized and released from the x-organ sinus gland complex, is primarily involved in carbohydrate metabolism; biogenic amines and peptidergic neuroregulators are known to modulate the release of CHH. Marked elevations of hemolymph glucose titers, which peaked within 2 h, were observed in both intact and bilaterally eyestalk-ablated prawns, Macrobrachium rosenbergii, when they were transferred directly from their optimal temperature of 28 °C to lower temperatures close to their lethal limit. Hyperglycemia can therefore be considered a characteristic response in this species under cold shock. Involvement of biogenic amines in the hyperglycemic response was also demonstrated. Hyperglycemic effects of epinephrine, dopamine and serotonin were mediated through CHH at the eyestalk level, but the response under cold shock was not exclusively mediated through CHH. It is suggested that factor(s) other than CHH are involved in the hyperglycemic response, possibly norepinephrine or/and octopamine.

Involvement of biogenic amines and amino acids in the central regulation of cardiovascular homeostasis

Involvement of biogenic amines and amino acids in the central regulation of cardiovascular homeostasis

CATECHOLAMINE, VASOACTIVE INTESTINAL PEPTIDE AND THYROTROPHIN‐DEPENDENT cAMP LEVELS DISPLAY A DIFFERENT SENSITIVITY TO IODOTHYRONINES IN BOTH NORMAL AND PATHOLOGICAL HUMAN THYROID CELLS IN CULTURE

As the interactions of iodothyronines on adrenergic and vipergic receptors are not clear, the effect of exogenous T3 and T4 on catecholamine- and VIP-induced cAMP accumulation in human normal thyroid cells after eight days of primary culture has been investigated. To evaluate the effect of endogenous iodothyronines, the response of the adenylate cyclase system to isoprenaline, adrenaline, VIP, and TSH was studied during a 10 d period. T3 and T4 were unable to modify the catecholamine- and VIP-induced cAMP accumulation in human normal thyroid cells after 6-8 days of culture, while the response to TSH was significantly inhibited. In cells cultured from thyrotoxic tissue, the response of the adenylate cyclase system to catecholamines and VIP, during a 10 d primary culture, showed a behaviour similar to controls. TSH responsiveness was negligible up to the fourth day of culture, while in normal cells a response to all the agonists was present from the beginning. In view of the lack of effect of iodothyronines on catecholamine- and VIP-induced cAMP accumulation, and of the superimposable behaviour of the response to catecholamines and VIP in normal and hyperthyroid cells during the first days of culture, we can conclude that iodothyronines do not directly modify the response of the adenylate cyclase system to adrenergic and vipergic stimulation in human thyroid follicular cells. The lack of responsiveness to TSH of cells obtained from hyperthyroid tissue during the first 4 d of culture, associated with normal responsiveness to catecholamines and VIP, points to a possible involvement of biogenic amines and neuropeptides in sustaining such hyperthyroid states.

Lithium and central monoamine neurotransmitter systems

AbstractLithium salts have been in use in psychiatric medicine for the past three decades, but their mechanism of action is still unknown. Studies using a model of mania to delineate the means by which they exert their therapeutic effect have been hampered by the lack of a suitable animal analogue, although attempts have been made to induce a “manic” state in rodents. For this reason, most investigations of the neurochemical basis of lithium action have used normal animals, and have focused primarily on the monoaminergic neurotransmitters, mainly because of the predominant theory of affective disorders (the “biogenic amine hypothesis”). Data indicate that these neurotransmitter substances are affected by lithium administration, although the findings are not always consistent and it is therefore difficult to determine exactly their role in the antimanic effect of lithium and the pathogenesis of the bipolar affective disorder. While animal studies have confirmed the existence of a “withdrawal” phenomenon, the involvement of biogenic amines or of central Y‐aminobutyric acid (GABA)minergic system in the rapid recurrence of psychotic symptoms soon after cessation of lithium therapy is still equivocal.

Involvement of biogenic amines with the mechanisms of novel analgesics

1. 1. The analgesic activity of the kappa opioid agonist, U-50,488H, was markedly antagonized by pretreatment with reserpine, p-chlorophenylalanine, and ketanserin. Likewise, analgesic doses of U-50,488H enhance serotonin metabolism. These results suggest that kappa analgesia requires serotonin acting through 5-HT 2 receptors. 2. 2. The non-opioid analgesic, nefopam HCl, though a blocker of biogenic amine uptake, displays an analgesic spectrum of action more similar to that of amphetamine than that of the tricyclic antidepressants or serotonin uptake blockers. Likewise p-chlorophenylalanine and ketanserin do not block nefopam analgesia nor do naloxone, atropine, yohimbine, propranolol or haloperidol. However, as reserpine does block nefopam analgesia, biogenic amines acting at other receptors may be involved. 3. 3. The observation that m-tyrosine causes behavioral effects similar to high doses of nefopam suggested that they might be acting through similar mechanisms. However, although m-tyrosine causes analgesia, it is blocked by yohimbine. This suggests that alpha 2-adrenoreceptors are involved in m-tyrosine analgesia and that it differs in mechanism from nefopam analgesia.

Biogenic amines and depression (introduction to symposium).

The involvement of biogenic amines--primarily noradrenaline (NA) and serotonin (5-HT)--in depressive disorders was suggested by the finding more than twenty years ago that imipramine possessed antidepressant properties and concomitantly altered the availability of NA in the brain. Since then, numerous antidepressants closely related chemically and pharmacologically to imipramine have been introduced. It has generally been assumed that these "tricyclics" alleviate depression by influencing the neurotransmitters (NA, 5-HT) at crucial receptor sites in the brain. Thus, the "biogenic amine hypothesis of depression" postulates that depression is due to a reduced functional activity of one or more brain amines. The tricyclics appear to be antidepressants due to their inhibition of the neuronal reuptake of NA in the brain. A decade ago, Carlsson, Coppen, Lapin, van Praag and other suggested that compounds selectively affecting the 5-HT uptake mechanism might be more effective antidepressants. This symposium will describe the clinical and preclinical results with zimelidine--the first 5-HT-selective uptake inhibitor.

EFFECT OF RESERPINE ON PLASMA CONCENTRATIONS OF GROWTH HORMONE AND PROLACTIN IN THE DOMESTIC FOWL

Department of Zoology, University of Hull, Hull, HU6 7RX, * Department of Physiology, Rutgers University, New Brunswick, New Jersey 08903, U.S.A. and †Department of Pure and Applied Zoology, University of Leeds, Leeds, LS2 9JT (Received 9 June 1978) It has been established that biogenic amines are involved in control of the secretion of prolactin (MacLeod, 1976) and growth hormone (GH; Martin, 1976) in mammals. In birds there is very little evidence for this, although in the domestic fowl it has recently been demonstrated that sytemically administered catecholamines (adrenaline and noradrenaline) markedly lower the concentration of GH in the peripheral plasma (Harvey & Scanes, 1978) and that serotonin stimulates the release of prolactin from incubated hemipituitary glands (Border & Chadwick, 1977). Therefore, to elucidate further the possible involvement of biogenic amines in the regulation of GH and prolactin secretion, the effect of reserpine (a 5-hydroxytryptamine- and catecholamine-depleting agent) on the concentrations

Involvement of biogenic amines in drug-induced aggressive pecking in chicks.

Pairs of neonate chicks were administered psychoactive agents and pecks against each other were recorded during 4-hr test sessions. The first experiment assessed where drug-induced aggressive pecking could serve as a useful anti-depressant screening model. Although pecking was induced by tricyclics, d-amphetamine, and L-Dopa, ineffective agents included a MAO inhibitor (pargline) and a tricyclic indole antidepressant (iprindole). These data cast doubt on the validity of the chick pecking model as a specific antidepressant tests. A second experiment attempted to determine where different amines were involved in pecking induced by an antidepressant and a CNS stimulant. Pairs of chicks were pretreated with various doses of amine antagonists, and a standard dose of imipramine (IMI) or d-amphetamine (AMP) was administered. Haloperidol completely antagonized AMP but not IMI pecking, while phentolamine and propranolol did not modify AMP pecking, suggesting involvement of dopamine. Pecking induced by IMI was partially antagonized by a dose of methysergide ineffective in modifying AMP pecking. Neither phentolamine nor propranolol blocked IMI pecking. Serotonin was further implicated in IMI pecking in a third experiment, whether chronic PCPA pretreatment significantly decreased IMI, but not AMP pecking. These data suggest that aggressive pecking induced by AMP and IMI may be mediated by different amine systems.

Involvement of biogenic amines in memory formation: the central nervous system indole amine involvement.

Drugs administered after training and reported to alter central nervous tissue indole amine levels are shown to affect memory of a single trial passive avoidance training event of female CF-1 mice. Results indicate the normal levels of indole amines are necessary during the formative phase of memory for normal levels of memory.

Involvement of biogenic amines in memory formation.

Drugs that deplete the biogenic amines of the central nervous system were found to impair the consolidation of memory, in mice, of an avoidance task. Results indicate that normal levels of one of the catecholamines are necessary for the formation of long term memory.