Enzymatic activities in brains of diabetic rats treated with vanadyl sulphate and sodium tungstate

The hypothesis of the present study was that diabetes mellitus might affect brain metabolism. Streptozotocin (STZ)-induced diabetic rats, treated with vanadyl sulphate (V) and sodium tungstate (T) were employed to observe the aspartate aminotransferase (AST), alanine aminotransferase (ALT) and creatine kinase (CK) activities in brain homogenates. Significant increases in AST, ALT and CK activities were found in diabetic brain homogenates against controls, suggesting increments of transamination in brain and/or increases in cell membrane permeability to these enzymes. The increase in brain CK possibly expresses alterations in energy production. The decrease in CK activity caused by V and T treatment in diabetic rats suggests that both agents tend to normalize energy consumption. It is also possible that V and T-induced hypoglycemic effects cause metabolic alterations in brain

Gametogênese e dinâmica da reprodução de Anodontites trapesialis (Lamarck) (Unionoida, Mycetopodidae) no lago Baía do Poço, planície de inundação do rio Cuiabá, Mato Grosso, Brasil Gametogenesis and dynamics of the reproduction of Anodontites trapesialis (Lamarck) (Unionoida, Mycetopodidae) from Baia do Poço Lake at the Cuiabá River wetland, Mato Grosso, Brazil

O ciclo reprodutivo de Anodontites trapesialis foi estudado entre os meses de maio de 1998 a abril de 1999. Análises quantitativas dos elementos celulares revelaram que a espécie é exclusivamente hermafrodita com folículos masculinos e femininos separados. A gametogênese é contínua com picos de maturação e eliminação de gametas durante a estação seca. A ovogênese tem seu período de maturação máxima em abril e maio, momento em que óvulos maduros são observados preenchendo os folículos e gonoductos. A espermatogênese foi reconhecida por uma fase proliferativa com células em desenvolvimento e apresentou seu período de maturação entre abril e julho. Estas células se diferenciaram dando origem às mórulas espermáticas e espermatozóides livres, organizando a série espermática radial. Durante o período de liberação dos gametas, a maioria dos folículos apresentou agregados de espematozóides formando esferas espermáticas as "spermballs", as quais caracterizam a espécie como espermatozeugmata.<br>The reproductive cycle of Anodontites trapesialiswas studied from May 1998 to April 1999. Quantitative analysis of the sexual cycle revealed that the species is exclusively hermaphrodite with separate male and female follicles. Gametogenesis is continuous with peaks of maturation and elimination of gametes during dry season. The period of maximum maturation of the oogenesis was in April and May, when mature oocytes were observed filling the follicles and gonoducts. Spermatogenesis was recognized by a proliferation phase with developing cells with period of maturation since April to July. These cells started to differentiate giving origin to spermatic morulae and free spermatozoa organizing the radial spermatic series. During the period of discharge of the gamets, the majority of follicles presented aggregates of spermatozoa forming the spermballs, which characterize the species as spermatozeugmata