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Biomedical subjects

C L Galli

Publications and source records attributed to C L Galli.

At least 109 records · Page 6Linked to original sources
PubMed1978

Light stimulates tyrosine hydroxylase activity and dopamine synthesis in retinal amacrine neurons.

Retinal dopamine-containing amacrine neurons are rapidly activated by light, as shown by an increase in the rate of dopamine formation in vivo and a concomitant increase in the activity of tyrosine hydroxylase, measured in vitro with a subsaturating concentration of pteridine cofactor. Activation of tyrosine hydroxylase also occurs when isolated eyes from rats killed in the dark are exposed to a strobe light. Studies of amacrine neurons should provide basic data about the biochemical processing of visual information, as well as the physiological presynaptic regulatory mechanisms of dopamine-containing neurons.

Animals↗
PubMed1978

Significance of dopamine metabolites in the evaluation of drugs acting on dopaminergic neurons.

The effect of various drugs was studied on 3-methoxytyramine (3-MT) concentrations in rat striatum. The drugs were chosen for their ability to interfere with the dopaminergic system at different levels. Dopamine (DA) acidic metabolites, i.e. homovanillic acid (HVA) and 3,4-dihydroxyphenylacetic acid (DOPAC), were also measured. Changes of 3-MT, unlike those of DOPAC and HVA, seem to reflect the functional activity of dopaminergic neurons. In fact drugs believed to increase or decrease DA content in the synaptic cleft produce predictable changes of striatal 3-MT. Thus cocaine, nomifensine and d-amphetamine increase 3-MT concentrations while gamma-butyrolactone, alpha-methyltyrosine and apomorphine decrease it.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1977

Activation of the nigrostriatal dopaminergic pathway by injection of cholera enterotoxin into the substantia nigra.

Twenty-four hours after unilateral injection of cholera enterotoxin into the rat substantia nigra there is an increase, in the striatum on the injected side, of basal adenylate cyclase activity, 3,4-dihydroxyphenylacetic acid, and 3-methoxy-4-hydroxyphenylacetic acid. Moreover, there is an increase of motor activity, and rats tend to circle contralateral to the side of the injection. Injection of cholera enterotoxin into brain nuclei may be a useful procedure for pharmacologically activating selected neuronal systems of brain and for studying the pharmacology of drugs that are suspected of interacting with these systems.

3,4-Dihydroxyphenylacetic Acid↗
PubMedDate not supplied

Mixtures of benomyl, pirimiphos-methyl, dimethoate, diazinon and azinphos-methyl affect protein synthesis in HL-60 cells differently.

Dimethoate, azinphos-methyl, diazinon and pirimiphos-methyl, widely used organophosphorous insecticides, and benomyl, a benzimidazole fungicide, induce different cytotoxic effects on the human leukemia cell line HL-60. Among the insecticides tested, only azinphos and diazinon induced a dose-related inhibition of protein synthesis in HL-60 cells at 24 h, at 60 and 40 micrograms/ml medium, respectively. Dimethoate and pirimiphos were not active up to 100 micrograms/ml. Benomyl strongly inhibited protein synthesis at 50 micrograms/ml and the polymerisation of actin to give cytoskeletal microfilaments (F-actin) at 30 micrograms/ml. Mixtures of benomyl-pirimiphos and dimethoate azinphos-diazinon were also investigated. Pirimiphos, when present in equal concentration, antagonized the inhibitory effect of benomyl on protein synthesis at 4 h, but not at 24 h. The effect of the other insecticide mixture on the same parameter was greater than that of the two active components, diazinon and azinphos given singly.

Actins↗
PubMedDate not supplied

Ultrasonic vocalization in rat pups as a marker of behavioral development: an investigation of the effects of drugs influencing brain opioid system.

Early postnatal exposure to morphine significantly influenced the ultrasonic vocalization of rat pups removed from their nest. In particular, a significant decrease in the rate of calling, sound pressure level and range of frequency was found in morphine-treated animals; moreover, the duration of calls was significantly increased by morphine administration. Conversely, neither beta-casomorphins (beta CMS), which are opioid peptides derived from the enzymatic digestion of milk protein (beta-casein), nor an opioid antagonist, like naloxone, significantly affected ultrasonic emission. The results are discussed with particular reference to the role of the opioid system in separation distress-induced vocalization in young animals.

Aging↗
PubMedDate not supplied

Postnatal ontogenesis of dopaminergic and serotoninergic systems in rat caudate nucleus.

The development and sex differences of the catecholaminergic and serotoninergic systems were studied in rat caudate nucleus by measuring dopamine, serotonin and their metabolites in male and female pups from birth up to day 30 of life. Dopamine increased regularly during the entire period studied, while its metabolites, dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), increased sharply only after day 9 of life. At birth, serotonin levels were 50% of the juvenile value; its metabolite, 5-hydroxyindoleacetic acid (5-HIAA), increased greatly after day 6 of life. No difference was observed in male and female neurotransmitter ontogenesis. The results indicated that dopaminergic and serotoninergic systems were not mature in the caudate nucleus at birth. A functional immaturity of enzyme systems involved in neurotransmitter synthesis and/or catabolism is suggested.

Animals↗