Related Experiment Video
Updated: Aug 14, 2026
08:00
Observation of the Ciliary Movement of Choroid Plexus Epithelial Cells Ex Vivo
Published on: July 13, 2015
[Chloroquine-induced achromotrichia. An ultrastructural study]
P H Asch1, P Caussade, C Marquart-Elbaz
1Clinique Dermatologique, Hôpitaux Universitaires de Strasbourg, France.
Annales De Dermatologie Et De Venereologie
|January 1, 1997
Summary
Chloroquine treatment can cause hair graying (achromotrichia) by damaging melanocytes, impairing melanin production. This hair color change is reversible after discontinuing the drug.
Area of Science:
- Dermatology
- Cell Biology
- Toxicology
Background:
- Chloroquine is used to treat conditions like subacute lupus erythematosus.
- Drug-induced achromotrichia (hair graying) is a known side effect of chloroquine.
- The exact mechanism of chloroquine-induced achromotrichia remains unclear.
Observation:
- A 21-year-old patient developed achromotrichia during chloroquine therapy.
- Electron microscopy revealed ultrastructural anomalies in hair root melanocytes.
- Observed anomalies included densified nuclei and accumulation of immature melanosomes.
Findings:
- Melanocytes showed impaired melanin synthesis and melanosome maturation.
- Reduced transfer of melanosomes from melanocytes to keratinocytes was noted.
- Accumulation of immature melanosomes led to inactive melanocytes.
Implications:
- Chloroquine appears to exert a toxic effect on melanocytes.
- These findings suggest a direct impact on melanin production pathways.
- Understanding this mechanism could inform management of drug-induced side effects.
Related Concept Videos
01:11Channel Rhodopsins
Most organisms use photoreceptors to sense and respond to light. Examples of photoreceptors include bacteriorhodopsins and bacteriophytochromes in some bacteria, phytochromes in plants, and rhodopsins in the photoreceptor cells of the vertebral retina. The light-sensitive property of these receptors is because of the bound chromophores, such as bilin in the phytochromes and retinal in the rhodopsins.
Rhodopsins belong to the family of cell surface proteins called G-protein coupled receptors,...
Rhodopsins belong to the family of cell surface proteins called G-protein coupled receptors,...
01:21Antiprotozoal Agents
Leishmaniasis is a widespread parasitic disease caused by several Leishmania species. It affects millions of people each year and remains a major public health problem in endemic regions. First-line treatment relies on pentavalent antimonials, including meglumine antimoniate and sodium stibogluconate. Even so, how these drugs work has not been fully clear, especially their interaction with parasite-specific biochemical pathways. One key target is trypanothione reductase (TR), an enzyme that...