Tyrosine hydroxylase activity in peripherally denervated rat pineal gland.
The presence of tyrosine hydroxylase (TH) in the rat pineal gland was studied using a combination of immunochemical and biochemical methods. In superior cervical ganglionectomized (SCGx) animals and in isolated pineals incubated for 72 h, both TH immunoreactive (TH-IR) fibers and TH biochemical activity were still present but reduced. Conversely, in dispersed pinealocytes incubated for only 24 h we were unable to detect either TH activity or TH-positive cells. Since in the pineal gland of intact rats total 3-methoxy-4-hydroxy phenylglycol (MHPG) was undetectable, and only traces of norepinephrine (NE) were present in the pineal of ganglionectomized animals, the results suggest a central pinealopetal catecholaminergic pathway which could use dopamine as a neurotransmitter.
Hernández
G
G
Department of Physiology, University of La Laguna, Tenerife, Spain.
Bello
A R
AR
López-Coviella
I
I
Abreu
P
P
Fajardo
N
N
Reiter
R J
RJ
Hernández
A
A
Alonso
R
R
D000818:Animals; D004298:Dopamine / Q000032:analysis / Q000502:physiology*; D008297:Male; D008734:Methoxyhydroxyphenylglycol / Q000032:analysis; D009419:Nerve Tissue Proteins / Q000032:analysis*; D009638:Norepinephrine / Q000032:analysis; D010870:Pineal Gland / Q000201:enzymology* / Q000294:innervation; D051381:Rats; D017207:Rats, Sprague-Dawley; D017783:Superior Cervical Ganglion / Q000502:physiology / Q000601:surgery; D013562:Sympathectomy; D014446:Tyrosine 3-Monooxygenase / Q000032:analysis*
D009419:Nerve Tissue Proteins; D008734:Methoxyhydroxyphenylglycol; D014446:Tyrosine 3-Monooxygenase; D004298:Dopamine; D009638:Norepinephrine