RESUMO
This study was conducted to evaluate phosphatidylserine translocation in head plasma membrane of Percoll-gradient purified of rabbit cauda epididymal sperm during capacitation and acrosome reaction (AR) using Annexin-V. Propidium iodide was used as control to reject dead or dying cells. The presence and distribution of Annexin-V binding sites were analyzed using flow fluorocytometry and confocal microscopy. After 6 h of incubation of sperm in capacitation medium, the number of cells positively stained with Annexin-V showed a small but significant increment. The Annexin-V binding sites produced during capacitation were found mainly in the post-acrosomal region of the sperm head plasma membrane. After AR induction with progesterone, the localization of phosphatidylserine was changed and the Annexin-V binding sites were found almost only in the acrosomal region, but with higher number of binding sites in the equatorial area. On the contrary, after AR induction with A23187, phosphatidylserine translocation, although predominant over the acrosomal region, was also observed in the post-acrosomal region. Plasma membrane destabilization during capacitation and AR may be important for sperm-oocyte fusion.
Assuntos
Reação Acrossômica/fisiologia , Membrana Celular/química , Lipídeos de Membrana/análise , Fosfolipídeos/análise , Capacitação Espermática/fisiologia , Cabeça do Espermatozoide/ultraestrutura , Animais , Anexina A5 , Feminino , Fluoresceína-5-Isotiocianato , Masculino , Óvulo/fisiologia , CoelhosRESUMO
Cell death can occur through apoptotic or necrotic death pathways. Membrane disruption leads to inflammation, a typical feature of necrosis. Apoptosis constitutes a genetically controlled physiologic process of cell removal. It is characterized by cell shrinkage, chromatin condensation, and DNA cleavage. Apoptotic cells are rapidly recognized and engulfed by phagocytes thus inhibiting an inflammatory response following necrosis. Apoptosis has been proposed as a basic event to protect tissue homeostasis. This paper analyzes the genetic, biochemical, and morphologic characteristics related to apoptosis, as well as its relationship to certain illnesses.
Assuntos
Apoptose , Apoptose/genética , Doença , HumanosRESUMO
The differential quantitative participation of apoptosis and necrosis in ewe antral follicles of two different sizes, separated in four stages of atresia using macroscopic, histologic, and esteroid quantification methods was assessed. Annexin V binding and propidium iodide (PI) uptake was used to detect healthy live cells (Annexin V negative/PI negative), early apoptotic cells (Annexin V+/PI-), and necrotic or late apoptotic cells (PI+). Additionally we used internucleosomal DNA fragmentation as a quantitative estimate of apoptosis. Presence and distribution of lysosomal enzymes in follicular fluid and granulosa cells was used as a measure of necrotic cell death. DNA flow cytometry and gel electrophoresis were positively correlated with the progression of atresia, small atretic follicles tend to have higher percentages of internucleosomal cleaved DNA than follicles >6 mm. Annexin/PI binding also indicates that apoptosis and necrosis increase with atresia progression, generally apoptosis outweighs necrosis in small follicles. Acid phosphatase and glucosaminidase in follicular fluid of 3-6 mm follicles showed no significant modifications between healthy and initially atretic follicles, and only a small, but significant increase in activity in advancedly atretic follicles. On the contrary, lysosomal enzyme activity in follicles >6 mm showed positive correlation between atresia stages and the activities of acid phosphatase and glucosaminidase in follicular fluid. A similar size-differential behavior was found in free or membrane-bound lysosomal enzyme activity of granulosa cells. Necrosis, but principally apoptosis, were present during all stages of follicular maturation indicating that growth and maturation of ovarian follicles involves a continuous renewal of granulosa cells, regulated by apoptosis. Mechanisms regulating this equilibrium may participate in the final destiny, whether ovulation or atresia of ovarian follicles.
Assuntos
Atresia Folicular/fisiologia , Líquido Folicular/enzimologia , Células da Granulosa/enzimologia , Lisossomos/enzimologia , Fosfatase Ácida/metabolismo , Animais , Anexina A5/metabolismo , Apoptose , Ciclo Celular , Fragmentação do DNA , Eletroforese em Gel de Ágar , Estradiol/metabolismo , Feminino , Citometria de Fluxo , Hexosaminidases/metabolismo , Necrose , Nucleossomos/genética , Progesterona/metabolismo , OvinosRESUMO
The systemic action of certain psychotropic drugs (haloperidol, penfluridol, trifluoperazine pimozide and verapamil) inhibitors of calcium-calmodulin-system, some biochemical and morphological parameters during the sexual differentiation of hypothalamus in neonatal (72 hours) male and androgenized female rats were studied. The hypothalamic weight in normal adult rats of both sexes not changed (39.7 +/- 3.79 vs 40.57 +/- 7.60 mg); however, verapamil increased the hypothalamic weight (table II), haloperidol and pimozide were the most effective (1.50 +/- 0.49 g and 2.00 +/- 0.11 g respectively). The testosterone administered to newborn females decreased the ovary development (46.3 +/- 4.5 mg. vs 23.1 +/- 2.7 mg), the haloperidol and pimozide partially reverted this effect.