Drug-Induced Changes in the Cytoplasmic Ribonucleoprotein Constituents of Brain Tissue

Abstract

Studies carried out on the properties of isolated ribosomes from drug-treated brain cortex slices indicate that ribosomes from drug-treated tissues are generally more susceptible to breakdown into smaller components such as proteins, nucleic acids, acid-soluble nucleotides, etc. It seems that some factor or factors responsible for the stability of the complex macromolecular structure of ribonucleoproteins of brain tissue are affected as a result of drug treatment. Ribosomal RNA from drug-treated brain tissue has been isolated under standardized conditions and the secondary structures of RNA have been studied by methods involving thermal hyperchromicity and reaction with formaldehyde. This latter study indicates that, during the action of some of these neuropharmacological drugs, the secondary structure of ribosomal RNA of brain tissue is partially lost. The loss in the stability of cytoplasmic ribonucleoproteins in drug-treated brain tissue may partly be due to the disorganization at the level of the secondary structure of the RNA component.

Mescaline-induced changes of brain-cortex ribosomes. Effect of mescaline on the stability of brain-cortex ribosomes

“…1962). It has been further observed that when brain-cortex slices are incubated in the presence of different convulsant and antidepressant drugs the ribosomal particles become more susceptible to degradation, releasing protein, RNA and acid-soluble nucleotides (Datta & Ghosh, 1963aGhosh et al 1965). The results of the present study also indicate that mescaline induces some instability in the ribosomal particles and makes them susceptible to degradation into their components (Table 4 and Fig.…”

Mescaline-induced changes of brain-cortex ribosomes. Effect of mescaline on the hydrogen-bonded structure of ribonucleic acid of brain-cortex ribosomes

“…In the preceding paper (Datta & Ghosh, 1970) it was reported that when brain-cortex slices are treated with mescaline sulphate (3,5,6-trimethoxyphenethylamine sulphate) the ribosomal particles become more susceptible to breakdown releasing protein, RNA, acid-soluble nucleotides and amino acids. Similar effects were previously observed during the action of convulsant and antidepressant drugs on brain-cortex slices (Datta & Ghosh, 1963aGhosh, Datta & Bhattacharyya, 1965). Since secondary structure plays a pivotal role in maintaining the stability or integrity of both RNA and protein, an attempt was made in the present study to examine the molecular mechanism of susceptibility or disorganization of RNA of ribosomal particles isolated from brain-cortex slices previously treated with mescaline.…”

“…This is especially true in nucleic acids, which are said to constitute the principal cerebral components of learning and behaviour. Although there is no known relevance of the observed lowering of hydrogen-bonded structures of RNA to the pharmacological activities of mescaline, the previous observations that convulsant, centralnervous-system-stimulant and psychotomimetic drugs affect the stability of ribosomal particles (Datta & Ghosh, 1963a, 1964b, 1970Ghosh, et al 1965;Ghosh, Datta, Chanda & Sikdar, 1962), together with the present observations, appear to point towards a relationship between the neurotropic effects of these drugs and the structural integrity of the RNA molecules of brain cells.…”