Protein kinase G I immunoreaction is colocalized with arginine-vasopressin immunoreaction in the rat suprachiasmatic nucleus.
The suprachiasmatic nucleus (SCN) contains the primary mammalian circadian clock. This clock is entrained to environmental rhythms by external stimuli called zeitgebers. This entrainment is accomplished by the activation of specific, interacting signal transduction cascades. Since a cyclic guanosine monophosphate-dependent mechanism play a crucial functional role for light entrainment in the late night and for transmission of cholinergic stimuli, we examined the expression of protein kinase (PKG) in the rat SCN by means of qualitative and semi-quantitative immunocytochemistry. Immunoreaction (IR) for the isozyme protein kinase G I (PKG I) was found in the dorsomedial part of the SCN considered as an important relay in the output pathways of the clock. Within the SCN, PKG-I IR was colocalized with arginine-vasopressin-IR. The intensities of the PKG-I-IR did not vary between day and night.
Revermann
Marc
M
Dr Senckenbergische Anatomie, Institut für Anatomie II, Fachbereich Medizin, Johann Wolfgang Goethe-Universität, Theodor-Stern-Kai 7, D-60590 Frankfurt/Main, Germany.
Maronde
Erik
E
Ruth
Peter
P
Korf
Horst-Werner
HW
D000818:Animals; D001127:Arginine Vasopressin / Q000378:metabolism*; D002940:Circadian Rhythm / Q000502:physiology*; D017869:Cyclic GMP-Dependent Protein Kinases / Q000378:metabolism*; D007150:Immunohistochemistry; D008297:Male; D009474:Neurons / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013493:Suprachiasmatic Nucleus / Q000378:metabolism*
D001127:Arginine Vasopressin; D017869:Cyclic GMP-Dependent Protein Kinases