Effect of acute acetyl-l-carnitine treatment on daytime melatonin synthesis in the rat.
The effects of acute treatment of young male rats with 350 mg/kg of acetyl-l-carnitine (ALCAR) at 15.00 hr on the synthesis and secretion of melatonin by the pineal gland and the retinas were studied 1 hr after injection. The pineal N-acetyltransferase (NAT) activity was unchanged when compared with the control. However, there was a non-significant but slight increase in the melantonin content of the pineal glands in the ALCAR-treated rats. The serum level of melantonim in the ALCAR-treated group was significantly higher (P < 0.05) when compared with the control. The melatonin content of the retinas in the ALCAR treated rats was significantly higher than the control (P < 0.03). This result suggests that the high melatonin content in blood 1 hr after treatment with ALCAR was not as a result of the increased synthesis and secretion rate of melatonin by the pineal gland but rather from extra-pineal source, retina.
Olatunji-Bello
I I
II
Department of Cellular and Structural Biology, University of Texas Health Science Center, San Antonio, USA.
Reiter
R J
RJ
D000108:Acetylcarnitine / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001191:Arylamine N-Acetyltransferase / Q000032:analysis; D002940:Circadian Rhythm / Q000187:drug effects*; D004353:Drug Evaluation, Preclinical; D007274:Injections, Intraperitoneal; D008297:Male; D008550:Melatonin / Q000032:analysis / Q000097:blood / Q000378:metabolism*; D010870:Pineal Gland / Q000737:chemistry / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012160:Retina / Q000737:chemistry / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism*; D013997:Time Factors
D000108:Acetylcarnitine; D001191:Arylamine N-Acetyltransferase; D008550:Melatonin