Neutral aminopeptidase and dipeptidyl peptidase IV activities in plasma of monosodium glutamate obese and food-deprived rats.
Biometric parameters, glycemia and activity levels of plasma neutral aminopeptidase (APN) and dipeptidyl peptidase IV (DPPIV) were measured in monosodium glutamate obese and food-deprived rats (MSG-FD), to analyze the involvement of these enzymes in such situations. Plasma APN was distinguished as sensitive (PSA) (K(m) = 7.8 x 10(-5) mol/l) and predominantly insensitive (APM) (K(m) = 21.6 x 10(-5) mol/l) to puromycin, whereas DPPIV was sensitive (DPPIV-DS) (K(m) = 0.24 x 10(-5) mol/l) and predominantly insensitive (DPPIV-DI) (K(m) = 7.04 x 10(-5) mol/l) to diprotin A. Although unchanged in the MSG and food-deprived animals, APM activity levels were closely correlated with body mass, Lee index, and mass of retroperitoneal fat pad in the food deprived, but not in the MSG animals. DPPIV-DI activity levels decreased by 33% and were correlated with body mass, Lee index, and mass of periepididymal fat pad in the food-deprived MSG rats. These data suggest that APM and DPPIV-DI are respectively related to the downregulation of somatostatin in food-deprived rats, and to the recovery of energy balance in MSG obese rats during food deprivation.
Alponti
Rafaela F
RF
Laboratory of Pharmacology, Instituto Butantan, São Paulo, Brazil.
Silveira
Paulo F
PF
D015081:2-Naphthylamine / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology; D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight / Q000502:physiology; D018826:CD13 Antigens / Q000097:blood*; D018819:Dipeptidyl Peptidase 4 / Q000097:blood*; D004789:Enzyme Activation / Q000187:drug effects / Q000502:physiology; D005260:Female; D005508:Food Deprivation / Q000502:physiology*; D006943:Hyperglycemia / Q000378:metabolism; D008297:Male; D009765:Obesity / Q000378:metabolism*; D009842:Oligopeptides / Q000494:pharmacology; D011691:Puromycin / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D012970:Sodium Glutamate / Q000494:pharmacology*
D001786:Blood Glucose; D009842:Oligopeptides; C013112:4-methoxy-2-naphthylamine; D011691:Puromycin; C041445:diprotin A; D015081:2-Naphthylamine; D018826:CD13 Antigens; D018819:Dipeptidyl Peptidase 4; D012970:Sodium Glutamate