PubMed Health⌕ Search

Biomedical subjects

J Forn

Publications and source records attributed to J Forn.

At least 73 records · Page 4Linked to original sources
PubMed1980

Acute, subacute and chronic toxicity of fosfosal.

Acute, subacute and chronic toxicity studies of 2-phosphonoxy benzoic acid (fofosal) were carried out in several animal species. LD50 values in mice and rats were determined at two pH values; an additional toxic effect of acidity was found at the lowest pH tested (pH = 1.0), specially so by i.p. route. Differences in LD5- values between mice and rats of either sex were not significant; however, acute toxicity of male rabbits was higher than that of rats and mice. Long-term toxicity studies revealed a slight growth retardation and a significant mortality at the highest dose tested (500 mg/kg). These studies showed that fosfosal produced no hematological, blood chemical or pathological changes.

Animals↗
PubMed1979

Ca2+ and cyclic AMP regulate phosphorylation of same two membrane-associated proteins specific to nerve tissue.

It was shown previously that addition of cyclic AMP (cAMP) to a synaptic membrane fraction incubated with [gamma-32P]ATP stimulated the phosphorylation of two proteins, designated proteins Ia and Ib, found only in nerve tissue. Addition of Ca2+ plus veratridine to synaptosomes preincubated with 32Pi stimulated the phosphorylation of two proteins with similar apparent molecular weights. Various techniques have now been used to determine whether the two proteins phosphorylated in synaptosomes in the presence of Ca2+ plus veratridine are the same as proteins Ia and Ib phosphorylated in synaptic membranes in the presence of cAMP. The proteins phosphorylated by the two procedures were extracted under similar conditions, had similar apparent molecular weights and charges, and were digested by collagenase at similar rates and to the same radioactive intermediates and end products. Furthermore, the two sets of proteins were digested by three other proteolytic enzymes to phosphopeptides with similar molecular weights. The results indicate that Ca2+ and cAMP are each capable of regulating the phosphorylation of proteins Ia and Ib.

Adenosine Triphosphate↗
PubMed1979

Regulation of the state of phosphorylation of specific neuronal proteins in mouse brain by in vivo administration of anesthetic and convulsant agents.

The effect of drug treatment in vivo on the state of phosphorylation of two specific neuronal proteins, proteins Ia and Ib, has been studied in mouse brain. For this purpose, animals were killed by immersion into liquid nitrogen, and proteins Ia and Ib were extracted by a procedure designed to prevent alterations in their state of phosphorylation. Several anesthetic agents (pentobarbital, chloral hydrate, and urethane) each caused a decrease in the state of phosphorylation of these proteins. Conversely, the convulsant agents pentylenetetrazol and picrotoxin each caused an increase in the state of phosphorylation of these proteins. Neither the anesthetic nor the convulsant agents affected the total amount of these proteins. The results are compatible with a role for proteins Ia and Ib in neuronal function.

Anesthetics↗
PubMed1979

Correlation between antiinflammatory activity and inhibition of prostaglandin biosynthesis induced by various non-steroidal antiinflammatory agents.

The effect of several non-steroidal antiinflammatory agents (some of them original from our laboratory) on prostaglandin biosynthesis in guinea pig lung (biological method) and in bovine seminal vesicles (spectrophotometric method) has been studied. When this effect is compared with the in vivo antiinflammatory activity determined in the rat carragenin foot edema and with the recommended clinical daily dose in rheumatoid arthritis, a good correlation between these properties was observed. Only mefenamic acid showed a clear discordance. The experience shows that inhibitory effect of antiinflammatory drugs on prostaglandin synthetase in vitro may be used to predict, in most cases, their antiinflammatory activity in vivo in the pharmacological screening of the new compounds. Structure-activity relationship in the UR-series is also discussed.

Animals↗
PubMed1978

Depolarizing agents and cyclic nucleotides regulate the phosphorylation of specific neuronal proteins in rat cerebral cortex slices.

The regulation of the state of phosphorylation of two specific neuronal proteins, designated protein Ia and protein 1b, has been studied in slices of rat cerebral cortex incubated in vitro. For this purpose, a method was developed that prevents dephosphorylation of these proteins during their extraction. When the slices were incubated in a standard Krebs-Ringer solution, proteins Ia and Ib were present almost entirely in the dephosphorylated form. Incubation with cyclic AMP, 8-bromo cyclic AMP, N6-monobutyryl cyclic AMP, or with a phosphodiesterase inhibitor, 3-isobutyl-1-methylxanthine, increased the phosphorylation of proteins Ia and Ib in the slices. Depolarization of neuronal membranes by high K+ or by veratridine was also associated with an increased phosphorylation of proteins Ia and Ib. The effect of depolarizing agents, but not that of cyclic nucleotides or 3-isobutyl-1-methylxanthine, required the presence of external Ca2+ in the incubation medium. Tetrodotoxin blocked the stimulation of the phosphorylation of proteins Ia and Ib induced by veratridine but not that induced by the other agents tested. Incubation of the brain slices with 8-bromo cyclic AMP, 3-isobutyl-1-methylxanthine, high K+, or veratridine also increased the state of phosphorylation of two other neuronal proteins found in extracts of the slices.

1-Methyl-3-isobutylxanthine↗