-
Article
Pituitary and Gonadal Effects of GnRH (Gonadotropin Releasing Hormone) Analogues in Two Peripubertal Female Rat Models
Central precocious puberty is commonly treated by gonadotropin releasing hormone (GnRH) agonists. To compare modes of action and effectiveness of GnRH analogues and assess treatment combinations of agonistic (...
-
Chapter
Algal Symbiosis in Flatworms
-
Chapter
Occurrence and comparative physiology of melatonin in evolutionary diverse organisms
Past studies have revealed melatonin as a common substance of living organisms, from cyanobacteria to plants and mammals. The fact that melatonin is present in the light receptors and cell types derived from p...
-
Article
The vertebrate pineal hormone melatonin is produced by the brown alga Pterygophora californica and mimics dark effects on growth rate in the light
Melatonin, a methoxylated indoleamine, plays a role as a mediator of darkness in animals as well as in the unicellular alga Gonyaulax polyedra Stein and was recently detected in higher plants. We report on the fi...
-
Article
Circadian rhythmicity in the stimulation of bioluminescence by biogenic amines and MAO inhibitors inGonyaulax polyedra
In the dinoflagellateGonyaulax polyedra bioluminescence was investigated in constant darkness. Light emission was stimulated considerably and specifically by the biogenic smines epinephrine, 5-methoxytryptamine, ...
-
Article
Differential light effects on the dark motility rhythm inEuglena gracilis by series of short light pulses: Induction of long-term fluctuations and holding of the circadian oscillator
Dark motility was measured by means of an infrared beam in stationary, 8- to 10-months-old autotrophic cultures ofEuglena gracilis, strain Z. Controls in constant darkness exhibited circadian rhythms for several ...
-
Article
Ultradian rhythmicity of tyrosine aminotransferase activity inEuglena gracillis: Analysis by cosine and non-sinusoidal fitting procedures
Although the geophysical periodicity of the earth's rotation corresponds to a biological cyclicity of ca. 24 h, cellular temporal organization comprises a multifrequency time structure, in which ultradian rhyt...
-
Article
Influence of temperature on biological rhythms
The various effects that temperature can exert on biological periodicities are reviewed. Particular consideration is given to the remarkable capability of many rhythms either to respond in a temperature depend...
-
Article
The cellular circadian oscillator —A fundamental biological mechanism corresponding to a geophysical periodicity
In correspondence to the geophysical cycle of the solar day, the majority of eucaryotic organisms exhibit the phenomenon of circadian periodicity. This type of biological rhythm is reviewed, mainly as cytologi...
