Cytotoxic T lymphocytes and natural killer cells destroy target cells via the polarized exocytosis of lytic effector proteins, perforin and granzymes, into the immunologic synapse. How these molecules enter target cells is not fully understood. It is debated whether granzymes enter via perforin pores formed at the plasma membrane or whether perforin and granzymes are first endocytosed and granz...

The platelet plasma membrane is lined by a membrane skeleton that appears to contain short actin filaments cross-linked by actin-binding protein. Actin-binding protein is in turn associated with specific plasma membrane glycoproteins. The aim of this study was to determine whether the membrane skeleton regulates properties of the plasma membrane. Platelets were incubated with agents that disrup...

The aim of this study was to assess whether refractoriness to long photoperiod (LP) could be reversed by subjecting tomcats to a period of short days. Our hypothesis was that photoperiod changes can avoid refractoriness and restore sperm quality and production to that before refractoriness. Tomcats (n = 6) were housed in a conditioned room with LP (12L: 12D) for 45 days of acclimation and then ...

four mature stallions were used to study the effect of enzymatic antioxidant catalase on freezability of turkmen stallion's sperm. collected semen from stallions were processed and pooled before being divided treatments (200×106  sperm/ml) and diluted with extenders supplemented with different levels of catalase [0 (control), 100 u/ml (cat100), 150u/ml (cat150) and 200u/ml (cat200)]. exten...

Results of the studies carried out on localization and photodynamic action of merocyanine 540 (MC540) on carcinoma of cervix (HeLa) cells are presented. Fluorescence microscopic study showed that when HeLa cells were incubated with MC540 in dark, the dye localized in plasma membrane of cells. Photoirradiation of cells in presence of MC540 led to enhancement of dye uptake, intracellular localiza...

Since, there is only few documented evidence referring to assessment of the clear specific actions of medicinal plant source or active constituents in rodent model, the present study is undertaken to evaluate the effective concentration of technical azadirachtin-A, a tetranortritarpinoid of neem seed kernel, to immobilizes the cauda epididymal spermatozoa within 20 seconds and effectively inhib...

Antioxidants partially ameliorated the negative effects of reactive oxygen species (ROS) produced during cryopreservation. The objective of the present study was to investigate the effect of reduced glutathione, ascorbic acid and α-tocopherol on the quality of frozen-thawed buck spermatozoa. Ejaculates were collected by artificial vagina from 8 bucks and microscopically evaluated at 37 0 C. The...

Thioridazine (TZ) is used mainly in the treatment of schizophrenia. However, hepatotoxicity as a life-threatening adverse effect is associated with its clinical use. In this context, we examined the cytotoxic mechanisms of TZ on freshly isolated rat hepatocytes to better understanding of the pathogenesis of TZ-induced hepatotoxicity. Hepatocytes were prepared by the method of collagenase enzyme...

Plant cells possess a number of membrane bound organelles that play important roles in compartmentalizing a large number of biochemical pathways and physiological functions that have potentially harmful intermediates or by-products. The plasma membrane is particularly important as it holds the entire cellular structure whole and is at the interface between the cell and its environment. Conseque...

Evidence supports the involvement of nitric oxide (NO) in a Varity of male reproductive processes such as spermatogenesis, spermiogenesis, sperm motion, sperm metabolism and sperm capacitation. However, Low concentration of NO is essential in biology and physiology of spermatozoa, but high amounts of NO is toxic and has negative effects on sperm functions. On the other hand, it is established t...