Effects of LSD on the development, histology and fine structure of the chick embryo

The effect of LSD on the surface of neuroepithelial cells

The neuroepithelial cells of 10 control chick embryos and of 22 exposed to lysergic acid diethylamide (LSD) (50 microgram/ml) were examined in scanning electron microscopy (SEM). In specimens exposed to LSD, the cells are swollen and their surface loses its cytoplasmic projections. Labelling techniques applied in transmission electron microscopy (TEM) show that ruthenium red attaches to the surface of the neuroepithelial cells in the form of a continuous dark line in both controls and treated specimens. However, when cationized ferritin or lanthanum is used, the label appears in the form of a continuous line in the controls whereas it is discontinuous in specimens exposed to LSD. These observations suggest that LSD alters the components of the neuroepithelial cell surface in the young chick embryo.

Genetic toxicology of lysergic acid diethylamide (LSD-25)

The acute and the chronic psychotomimetic potentials of the hallucinogen lysergic acid diethylamide (LSD-25) have been recognized for almost 40 years. That additional types of the biological effects should have come under scrutiny was directly attributable to widespread use and abuse of this drug on a world-wide basis. Although "genetic toxicology" encompasses a broad spectrum of disciplines, including many areas of highly specialized research, perhaps the most germane, and those on which this review has concentrated, are Clastogenicity, Mutagenicity, Teratogenicity and Oncogenicity. Based on our current understanding and interpretation of the available data, the genetic toxicology of LSD provides an excellent example of Newton's "third law of motion", e.g., to every force there is an equal and opposite reaction force. From the published material it is impossible to draw clear cut conclusions regarding any of the above "problem areas" in spite of the considerable scientific effort invested. Most of the in vitro studies performed on the clastogenicity of LSD indicate either suppression of mitosis or enhanced chromosome damage. However, extrapolation of such results to the in vivo situation is very difficult. With regard to in vivo human use of the drug, no concensus is attainable as to chromosome breakage and the inconsistencies within and between studies remain inexplicable. However, several of the "controlled" investigations assessing the in vivo effect of chemically pure LSD suggest a transient increase in lymphocyte chromosome breakage. On the other hand, the results of cytogenetic studies on experimental animals are contradictory. Although human studies are nonexistent, in those experimental organisms tested, using accepted techniques, LSD proved to be, at best, a weak mutagen, if mutagenic at all. Teratogenicity studies in animals are confusing due to the multitude of organisms and plethora of discriminant parameters studied. However, with regard to man there has been ample opportunity and one can conclude that LSD is not teratogenic. As to the drug's oncogenic potential, the 3 reported cases of leukemia in LSD users are most likely the result of coincidence.

The effect of LSD on the histology and ultrastructure of the neuroepithelium of young chick embryos: a stereological study

Five control chick embryos and fifteen exposed to LSD at concentrations of 2.5, 12.5 and 50 mug/ml were examined. The morphometric analysis performed at the light microscope level shows that (1) the section area of the neural tube increases with the two highest doses of lysergic acid diethylamide (LDS) employed, (2) the volume fraction of the intercellular spaces decreases with the two highest doses of LSD, (3) the volume fraction of the nuclei in the neural tube is not modified with any concentrations of LSD employed, (4) the volume fraction of the cytoplasm in the neural tube increases with all three concentrations, and (5) the nucleo-cytoplasmic ratio decreases with all three doses employed. Moreover, at the ultrastructural level, it was found that (1) the volume fraction of mitochondria in the cytoplasm decreases at doses of 12.5 and 50 mug/ml (2) the surface to volume ratio of the mitochondria is unchanged with any of the concentrations of LSD employed and (3) the surface density of the endoplasmic reticulum in the cytoplasm increases only with a dose of 2.5 mug/ml of LSD.

Teratologic effects of LSD in explanted early chick embryos

Chick embryos were explanted at stage; 4-7 and cultured for 20 h with or without LSD. At any stage 10 mug/ml LSD or higher caused abnormalities in axial structures, particularly somites, in over 50% of the embryos. LSD had no apparent effect on morphogenesis of the heart, but significantly lowered the pulse rate. Cellular degeneration occurred in severely affected structures, but LSD at embryotoxic doses caused alterations in neither cell morphology nor mitotic activity. The effects of LSD were not permanent, i.e., the embryos retained the ability to undergo normal morphogenesis when, after 4-5 h of treatment with 10 mug/ml LSD, they were subcultured on plain nutrient medium.