Effects of melatonin on heat production and enzymatic activity in diurnal and in nocturnal rodents.
1. Heat production by means of oxygen consumption (Vo2), and enzymatic activity of malate dehydrogenase (MDH), lactate dehydrogenase (LDH), and glucose-6-phosphate dehydrogenase (G6PDH) were studied in diurnal (Rhabdomys pumilio) as well as nocturnal (Praomys natalensis) murids, as a response to melatonin treatment. 2. A significant (P less than 0.001) increase in Vo2 was noticed in melatonin treated mice of both species at ambient temperatures of Ta = 6 degrees C, 25 degrees C, 30 degrees C and 34 degrees C, when compared to sham operated mice. A significant (P less than 0.001) increase was also recorded in body temperature (Tb) at Ta = 6 degrees C and 25 degrees C. 3. Enzymatic activity was significantly higher: P less than 0.001 for MDH and LDH in R. pumilio, P less than 0.05 for LDH, and P less tha 0.01 for MDH in P. natalensis, after melatonin administration when compared to sham operated animals.
D000818:Animals; D001833:Body Temperature Regulation / Q000187:drug effects*; D002940:Circadian Rhythm / Q000187:drug effects*; D004912:Erythrocytes / Q000201:enzymology; D005954:Glucosephosphate Dehydrogenase / Q000097:blood; D007700:Kinetics; D007770:L-Lactate Dehydrogenase / Q000097:blood; D008550:Melatonin / Q000494:pharmacology*; D010101:Oxygen Consumption / Q000187:drug effects; D012377:Rodentia; D013045:Species Specificity
D007770:L-Lactate Dehydrogenase; D005954:Glucosephosphate Dehydrogenase; D008550:Melatonin