Deuterium oxide (D2O) enhances the photosensitivity of Stentor coeruleus

Journal Article · Sun Dec 01 00:00:00 EST 1985 · Biophys. J.; (United States)

DOI:https://doi.org/10.1016/S0006-3495(85)83866-2· OSTI ID:5737460

Iwatsuki, K; Song, P S

Stentor coeruleus exhibits negative phototaxis and step-up photophobic response (avoiding reaction) to visible light (maximum at 610-620 nm in both responses). In the presence of deuterium oxide (D2O) the step-up photophobic response was markedly enhanced, whereas the phototactic orientation response was inhibited. The induction time for the step-up photophobic response was longer in D2O than in H2O, and the duration of ciliary reversal for the response was also longer in D2O than in H2O, indicating that certain steps of the sensory transduction chain are subject to solvent deuterium isotope effects. The enhancement of the step-up photophobic response in D2O was canceled by LaCl3, while the inhibition of the phototactic orientation response in D2O was partially removed by LaCl3, even though LaCl3 did not affect the phototactic orientation response. These results suggest that the sensory transduction mechanisms for the two photoresponses are different, although the photoreceptors (stentorin) are the same.

• Research Organization: Texas Tech Univ., Lubbock
• OSTI ID: 5737460
• Journal Information: Biophys. J.; (United States), Vol. 6
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
CILIATA
PHOTOSENSITIVITY
HEAVY WATER
BIOLOGICAL EFFECTS
DEUTERIUM COMPOUNDS
LANTHANUM
VISIBLE RADIATION
ANIMALS
ELECTROMAGNETIC RADIATION
ELEMENTS
HYDROGEN COMPOUNDS
INVERTEBRATES
METALS
MICROORGANISMS
OXYGEN COMPOUNDS
PROTOZOA
RADIATIONS
RARE EARTHS
SENSITIVITY
WATER
560164* - Radionuclide Effects-Internal Source- Microorganisms- (-1987)