Disaggregation of polysomes in fetal organs and maternal brain after administration of d-lysergic acid diethylamide in vivo

Changes in body temperature after administration of antipyretics, LSD, delta 9-THC and related agents: II

Antipyretics, in particular acetaminophen, aspirin and ibuprofen, constitute the single most important class of drugs used therapeutically for an effect on body temperature. Hallucinogens exert prominent actions on the central nervous system, and it is not surprising that, like so many other centrally-acting agents, they too often affect temperature. This compilation primarily covers the considerable amount of data published from 1981 through 1985 on the interactions of these drugs and thermoregulation, but data from many earlier papers not included in a previous compilation are also tabulated. The effects of agents not classically considered as antipyretics on temperatures of febrile subjects are also covered. The information listed includes the species used, the route of administration and dose of drug, the environmental temperature at which experiments were performed, the number of tests, the direction and magnitude of change in body temperature and remarks on special conditions, such as age or brain lesions. Also indicated is the influence of other drugs, such as antagonists, on the response to the primary agent.

Translational regulation in rat brain hemispheres

Present studies on the sensitivity of the transcription process in rat cerebral hemispheres showed that the relative abundance and translation of free and bound poly (A)+ mRNAs in a reticulocyte mRNA-dependent system were reduced following 1 h and 4 h of ethanol or pentobarbital administration with free being affected to a greater extent than the bound poly (A)+ mRNAs. In addition, the energy-dependent nucleocytoplasmic transport of in vivo [3H]labeled nuclear RNA to surrogate cytoplasm was modified in response to ethanol exposure. The translocation of the labeled nuclear RNA fraction occurred only to the microsomal/ribosomal fractions of the cytoplasm, was stimulated by cyclic cAMP and abolished when the cytoplasm was depleted of its protein factors following streptomycin treatment, thereby establishing the translocated RNA as messenger RNA. It is concluded that the neural cell, in response to ethanol exposure, modifies the efficiency of nuclear processing and transport of mRNA. This nuclear restriction probably occurs at multi-levels during the post-transcriptional modification of mRNAs.

Characterization of a translational inhibitor isolated from rabbit brain following intravenous administration of d-lysergic acid diethylamide

Intravenous administration of d-lysergic acid diethylamide (LSD) to rabbits results in a transient inhibition of brain protein synthesis in vivo and in vitro. A translational inhibitor that appears in the postribosomal supernatant fraction of cerebral hemispheres following LSD administration was partially purified by gel filtration on Sephadex G-150 and precipitation with 60% ammonium sulfate. This inhibitor, which was proteinaceous, reduced the translational capacity of an initiating cell-free protein synthesis system derived from brain. It also inhibited a messenger RNA-dependent reticulocyte lysate programmed with brain polysomes and a globin-synthesizing reticulocyte lysate system. Addition of the partially purified inhibitor to a brain cell-free protein synthesis system resulted in the decreased formation of ternary complexes as well as 40 and 80S initiation complexes, suggesting that the inhibitor affects an early step in the initiation of protein synthesis in brain.

Effect of intravenous administration of D-lysergic acid diethylamide on initiation of protein synthesis in a cell-free system derived from brain

An initiating cell-free protein synthesis system derived from brain was utilized to demonstrate that the intravenous injection of D-lysergic acid diethylamide (LSD) to rabbits resulted in a lesion at the initiation stage of brain protein synthesis. Three inhibitors of initiation, edeine, poly(I), and aurintricarboxylic acid were used to demonstrate a reduction in initiation-dependent amino acid incorporation in the brain cell-free system. One hour after LSD injection, there was also a measurable decrease in the formation of 40S and 80S initiation complexes in vitro, using either [35S]methionine or [35S]Met-tRNAf. Analysis of the methionine pool size after LSD administration indicated there was no change in methionine levels. Analysis of the formation of initiation complexes in the brain cell-free protein synthesis system prepared 6 h after LSD administration indicated that there was a return to control levels at this time. The effects of LSD on steps in the initiation process are thus reversible.

Heat shock protein in mammalian brain and other organs after a physiologically relevant increase in body temperature induced by D-lysergic acid diethylamide

A physiologically relevant increase in body temperature from 39.7 to 42.5 degrees C, which was generated after the intravenous injection of D-lysergic acid diethylamide (LSD), caused the induction of synthesis of a 74,000-dalton heat shock protein in the brain, heart, and kidney of the young adult rabbit. A marked increase in the relative labeling of a 74,000-dalton protein was noted after analysis of both in vivo labeled proteins and cell-free translation products of isolated polysomes. A temporal decrease in the synthesis of this protein was noted as LSD-induced hyperthermia subsided. The 74,000-dalton protein, which is induced in various organs of the intact animal at a body temperature similar to that attained during fever reactions, may play a role in homeostatic control mechanisms.

Cell-free translation of free and membrane-bound polysomes and polyadenylated mRNA from rabbit brain following administration of d-lysergic acid diethylamide in vivo

Free and membrane-bound polysomes and polyadenylated mRNA isolated from rabbit brain were translated in an mRNA-dependent rabbit reticulocyte lysate system. Electrophoretic analysis of the cell-free translation products demonstrated that although most of the nascent proteins were common to both free and membrane-bound brain polysomes, qualitative and quantitative differences were observed. Compared with the results obtained with purified polyadenylated mRNA, the addition of intact polysomes to the cell-free translation assay was more efficient and produced higher molecular weight products. Analysis of the translation products of free and membrane-bound polysomes revealed the appearance of 74K protein following neither LSD administration or hyperthermia induced by elevated temperature treatment. The presence of this 74K protein was verified by analysis of the translation products by two-dimensional gel electrophoresis.

Characterization of an initiating cell-free protein synthesis system derived from rabbit brain

Protein synthesis in the brain is known to be affected by a wide range of treatments. The detailed analysis of the mechanisms that are involved would be facilitated by the development of cell-free translation systems derived from brain tissue. To date, brain cell-free systems have not been fully characterized to demonstrate a capacity for initiation of translation. The following criteria were utilized to demonstrate that a cell-free protein synthesis system derived from rabbit brain was capable of initiation in vitro: (a) sensitivity of cell-free translation to the initiation inhibitor aurintricarboxylic acid (ATA); (b) binding of [35S]Met-tRNAf to 40S and 80S initiation complexes; (c) incorporation of labeled initiation methionine into high-molecular-weight proteins; and (d) the association of labeled exogenous mRNA with polysomes. The optimum conditions for amino acid incorporation in this system were 4 mM-Mg2+, 140 mM-K+, and pH 7.55. Incorporation was dependent on the addition of ATP, GTP, and an energy-generating system. Cell-free protein synthesis reflected the normal process, since a similar spectrum of proteins was synthesized in vitro and in vivo. This initiating cell-free translation system should have wide application in the analysis of the mechanisms whereby various treatments affect protein synthesis in the brain.

Effect of intravenous administration of d-lysergic acid diethylamide on subsequent protein synthesis in a cell-free system derived from brain

An initiating cell-free protein synthesis system derived from brain was utilized to demonstrate that the intravenous injection of d-lysergic acid diethylamide (LSD) to rabbits induced a transient inhibition of translation following a brief stimulatory period. Subfractionation of the brain cell-free system into postribosomal supernatant (PRS) and microsome fractions demonstrated that LSD in vivo induced alterations in both of these fractions. In addition to the overall inhibition of translation in the cell-free system, differential effects were noted, i.e., greater than average relative decreases in in vitro labeling of certain brain proteins and relative increases in others. The brain proteins of molecular weights 75K and 95K, which were increased in relative labeling under conditions of LSD-induced hyperthermia, are similar in molecular weight to two of the major "heat shock" proteins reported in tissue culture systems. Injection of LSD to rabbits at 4 degrees C prevented LSD-induced hyperthermia but behavioral effects of the drug were still apparent. The overall decrease in cell-free translation was still observed but the differential labeling effects were not. LSD appeared to influence cell-free translation in the brain at two dissociable levels: (a) an overall decrease in translation that was observed even in the absence of LSD-induced hyperthermia and (b) differential labeling effects on particular proteins that were dependent on LSD-induced hyperthermia.

Comparison of the effect of intravenous administration of d-lysergic acid diethylamide on free and membrane-bound polysomes in the rabbit brain

The intravenous administration of LSD to young adult rabbits resulted in the disaggregation of both free and membrane-bound classes of brain polysomes. Based on the analysis of LSD dosage and the time course of the LSD-induced brain polysome shift, it was found that free polysomes were more sensitive to the drug than the membrane-bound polysome fraction. LSD-induced hyperthermia may be involved in the disaggregation of free and membrane-bound polysomes, since a correlation was found between the extent of LSD-induced hyperthermia and the degree of brain polysome shift. Prevention of LSD-induced hyperthermia by maintaining the animal at 4 degrees C blocked the disaggregation of both polysome classes. Induction of hyperthermia by elevation of ambient temperature also resulted in a shift in free and membrane-bound polysomes. In all cases the disaggregation of polysomes to monosomes was not caused by RNase activation. During polysome disaggregation, polyadenylated mRNA associated with both free and membrane-bound polysomes was not degraded but was relocalized from polysomes to monosomes.

Selective effects of LSD and hyperthermia on the synthesis of synaptic proteins and glycoproteins

Protein synthesis in rabbit brain was inhibited following the intravenous injection of LSD. The incorporation of [35S]methionine into brain microsomal and synaptic fractions was decreased by 35-45% relative to control values. A selective increase was observed, however, in the relative labeling of a protein of molecular weight 75,000. Our previous studies have shown that LSD induces an increase in body temperature (i.e. hyperthermia) in rabbits. When LSD-induced hyperthermia was blocked the general reduction in labeling of microsomal and synaptic proteins was still apparent but the selective increase in relative labeling of the 75,000 dalton protein was not. Induction of hyperthermia by means other than LSD (i.e. elevation of ambient temperature) produced selective increases in the relative labeling of microsomal and synaptic proteins of molecular weight 75,000 and 95,000. These proteins are similar in molecular weight of two of the major 'heat shock' proteins whose synthesis is induced in several cultured cell lines following elevation of ambient temperature. Fractionation of [35S]methionine-labeled synaptic membranes by lectin affinity chromatography and analysis of [3H]fucose labeling patterns indicated that, in contrast to the general reduction in labeling of brain proteins, the synthesis of synaptic glycoproteins was not altered by LSD. The synthesis of glycosylated proteins present in other subcellular fractions was, however, reduced. These results suggest that LSD induced selective changes in the synthesis of brain proteins and that the synthesis of synaptic glycoproteins may be relatively resistant to drug administration.

Fate of mRNA following disaggregation of brain polysomes after administration of (+)-lysergic acid diethylamide in vivo

Intravenous injection of (+)-lysergic acid diethylamide into young rabbits induced a transient brain-specific disaggregation of polysomes to monosomes. Investigation of the fate of mRNA revealed that brain poly(A+)mRNA was conserved. In particular, mRNA coding for brain-specific S100 protein was not degraded, nor was it released into free ribonucleoprotein particles. Following the (+)-lysergic acid diethylamide-induced disaggregation of polysomes, mRNA shifted from polysomes and accumulated on monosomes. Formation of a blocked monosome complex, which contained intact mRNA and 40-S plus 60-S ribosomal subunits but lacked nascent peptide chains, suggested that (+)-lysergic acid diethylamide inhibited brain protein synthesis at a specific stage of late initiation or early elongation.