Cyclic changes of exopeptidase activities in the rat brain: a regional study.
The present report describes the activity of three neuropeptide-degrading enzymes, in 12 brain areas during the estrous cycle of Sprague-Dawley rats. The quantitation of the enzyme activities was performed by measuring the rate of hydrolysis of the chromogenic substrates Leu-, Lys- and Asp-2-naphthylamides, by neutral, basic and acid aminopeptidase (AP) activities, respectively. Lys- and Leu-AP activities show a significant increase during the proestrus stage in the hypothalamus and the pituitary gland. Also there is a significant increase of Leu-AP activity in the occipital cortex. No significant decreases for Asp-AP activity during the proestrus in the hypothalamus and the pituitary were observed. As the changes seem to be limited at the hypothalamic-pituitary axis, these findings could be interpreted to mean that these exopeptidase activities play a role in the hormonal changes that take place during the estrous cycle of the rat.
de Gandarias
J M
JM
Department of Physiology, Medical School, University of the Basque Country, Bilbao/Spain.
Echevarría
E
E
Irazusta
J
J
Casis
L
L
D000626:Aminopeptidases / Q000378:metabolism / Q000502:physiology; D000818:Animals; D001921:Brain / Q000201:enzymology* / Q000502:physiology; D004971:Estrus / Q000378:metabolism* / Q000502:physiology; D020689:Exopeptidases; D005260:Female; D043384:Glutamyl Aminopeptidase; D006062:Gonadotropins / Q000378:metabolism / Q000502:physiology; D006868:Hydrolysis; D007031:Hypothalamus / Q000201:enzymology / Q000502:physiology; D007931:Leucyl Aminopeptidase / Q000378:metabolism / Q000502:physiology; D010447:Peptide Hydrolases / Q000378:metabolism* / Q000502:physiology; D010902:Pituitary Gland / Q000201:enzymology / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains
D006062:Gonadotropins; D020689:Exopeptidases; D010447:Peptide Hydrolases; D000626:Aminopeptidases; D007931:Leucyl Aminopeptidase; D043384:Glutamyl Aminopeptidase