Adenosine effects on the rat pineal gland in vitro: cyclic adenosine monophosphate levels, N-acetyltransferase, and thyroxine type II 5'-deiodinase activities and melatonin production.
The presence of adenosine and its receptors in the pineal gland suggests that they could have a regulatory influence on pineal physiology. Rat pineal glands cultured in the presence of the adenosine analog 5'-N-ethylcarboxamido adenosine (NECA) promoted a significant increase in pineal adenosine 3'5'-monophosphate (cAMP) content, similar to that caused by the beta-adrenergic receptor agonist isoproterenol (ISO). A potentiation of the cAMP response occurred when the glands were simultaneously stimulated with both NECA and ISO. Whereas high cAMP levels induced by ISO were associated with an increased N-acetyltransferase (NAT) activity and rise in the melatonin production and release, the NECA-induced rise in cAMP concentration failed to promote an increase in the activity of either NAT or another pineal enzyme thyroxine 5'-deiodinase type II; likewise, pineal melatonin levels did not rise.
Nonaka
K O
KO
Department of Cellular and Structural Biology, University of Texas Health Science Center, San Antonio 78284-7762.
Reiter
R J
RJ
Withyachumnarnkul
B
B
Stokkan
K A
KA
Lerchl
A
A
D000241:Adenosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D019830:Adenosine-5'-(N-ethylcarboxamide); D000704:Analysis of Variance; D000818:Animals; D001191:Arylamine N-Acetyltransferase / Q000378:metabolism*; D003470:Culture Media; D000242:Cyclic AMP / Q000378:metabolism*; D007453:Iodide Peroxidase / Q000378:metabolism*; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D008550:Melatonin / Q000096:biosynthesis*; D009924:Organ Culture Techniques; D010870:Pineal Gland / Q000187:drug effects* / Q000201:enzymology; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains; D014665:Vasodilator Agents / Q000494:pharmacology*
D003470:Culture Media; D014665:Vasodilator Agents; D019830:Adenosine-5'-(N-ethylcarboxamide); D000242:Cyclic AMP; D007453:Iodide Peroxidase; D001191:Arylamine N-Acetyltransferase; D008550:Melatonin; D000241:Adenosine; D007545:Isoproterenol