Effects of Changes in Hydromineral Balance on Rat Brain Aspartyl, Arginyl, and Alanyl Aminopeptidase Activities

Abstract

In order to examine the possible relationship between the processing and inactivation roles of aminopeptidases and the disruption of water-electrolyte balance, we measured the activities of aspartyl aminopeptidase (Asp-Ap), arginyl aminopeptidase (Arg-Ap) and alanyl aminopeptidase (Ala-Ap) in certain brain areas (hypothalamus, hippocampus, thalamus and brain cortices) and in the pituitary gland in several models of hydrosaline change. The activity of hypothalamic membrane-bound Asp-Ap significantly decreased (more than 50%) following treatments which induced a hypovolemic state. Aminopeptidase M activity (membrane-bound Ala-Ap activity with low sensitivity to puromycin) was also significantly decreased by 53 % in the thalamus of rats under conditions of hypovolemia plus hyperosmolality in comparison to the control group. These results indicate that aminopeptidases in the central nervous system may be involved in the physiological regulation of hydromineral balance.

The Characteristics, Functions and Inhibitors of Three Aminopeptidases Belonging to the M1 Family

“…The wide distribution in animals, plant tissues and bacteria as well as fungi demonstrates that they are a kind of ubiquitous and multifunctional natural enzymes. Their common function is cleaving an amino acid from the free N-terminal of various biologically active peptides and proteins [2]. On the other hand, in different organs or cells, they have different distribution, which determines their different functions.…”

A cascavel Crotalus durissus terrificus (Viperidae: Crotalinae) como modelo experimental para o estudo do envolvimento de peptidases na sobrevida de espermatozóides

“…Prover respostas às seguintes questões: GASPARELLO-CLEMENTE et al, 2003;IRAZUSTA et al, 2001;IRAZUSTA et al, 2002;SILVEIRA et al, 2001;VARONA et al, 2003). Parte da fração PR foi destinada à microscopia eletrônica, conforme descrito no item 4.12.…”

“…A família ADAM (mais de 30 membros já foram identificados) também está associada com a fusão espermatozóide-óvulo (BLOBEL et al, 1990). No presente estudo, APB, PIP e POP foram detectadas apenas em FS, enquanto as demais atividades peptidásicas foram presentes em FS e FM de todos os tecidos e sêmen avaliados, seguindo um padrão encontrado em todos os tecidos de mamíferos IRAZUSTA et al, 2002;SILVEIRA et al, 2001;VARONA et al, 2003).…”