1,721,015 research outputs found
Administration of ciprofibrate to lactating mothers induces PPARα-signaling pathway in liver and kidney of suckling rats
No full text- It is well known that the hypolipidemic drug ciprofibrate induces peroxisome proliferation in rodent liver, which in turn leads to the oxidative stress, and modifies some parameters related to cell proliferation and apoptosis. The administration of ciprofibrate to rats during the lactating period determined in their pups significant modifications in hepatic peroxisome enzyme activities, induction of the PPARalpha-target gene, Cyp4a10, and perturbation in cell proliferation and apoptosis, which affected the size of the liver. Moreover, this modification was associated to about two-fold induction of mRNA-PPARalpha. On the contrary, in the kidney, although a similar two-fold up-regulation of PPARalpha was detected, the induction of both peroxisomal enzyme activities and Cyp4a10 were weak, and no alterations were detected, neither in cell cycle nor in the size of the tissue. Our results indicate that the response to ciprofibrate is stronger in the liver than in the kidney of newborn rats
Catabolismo dei perossisomi indotti da clofibrato in fegato di ratto. Dati biochimici e citochimici.
No full textInsulin-sperm interaction: effects on plasma membrane and binding to acrosome
No full textIn in vitro studies, viable, intact human spermatozoa took up free radioinsulin with an apparently non-receptor-mediated mechanism. However, when a colloidal gold-insulin complex was substituted for the radiotracer, no surface binding was visualized at the ultrastructural level. Upon sperm incubation in the presence of free insulin, a dose-dependent release of phospholipid phosphorus occurred, with a concomitant derangement of head cell membrane. After head membrane removal, spermatozoa-bound radioinsulin in a time- and concentration-dependent manner, the binding was displaceable by unlabeled insulin, and an exclusive localization of the colloidal gold-insulin complex was visualized at the acrosome level. On the basis of this evidence, both the plasma membrane and the acrosome seem to represent cytological targets for insulin
Oxygen consumption of human seminal plasma: Relationships with semen characteristics
No full textIt is possible to determine oxygen consumption rate in human seminal plasma through voltammetric measurements. The seminal fluid of the sterile patients in this investigation was characterized by an anomalous sperm motility. Also studied was a control group of proven fertile subjects. The mean value of oxygen consumption resulted greater in the reduced sperm motility group than in the control group. The polyaminoxidase system is the most important factor in oxygen consumption in seminal plasma; however, it is likely that the high toxicity of polyamine degradation products is the cause of reduced and/or anomalous sperm motility in some seminal fluids
Selective autophagy of clofibrate-induced rat liver peroxisomes. Cytochemistry and immunocytochemistry on tissue specimens and on fractions obtained by Nycodenz density gradient centrifugation
No full textFollowing short treatments with peroxisomal proliferators rodent liver undergoes a significant increase in the peroxisomal population, accompanied by specific induction of some peroxisomal enzymes; both phenomena are reversible and in a few days after drug withdrawal the control parameters are recovered. The involvement of lysosomal system in removal of proliferated peroxisomes has been widely suggested, and the autophagic phenomenon was mainly investigated in experimental conditions in which the administration of lysosomotropic drugs or, more generally, of digestive process inhibitors caused an accumulation of autophagic vacuoles. In the present research the removal of clofibrate-induced rat liver peroxisomes was investigated under physiological conditions, i.e. in the absence of drugs interfering with the autophagic process. In a previous paper the lysosomal Involvement in peroxisomal removal was suggested on the basis both of biochemical and cytochemical-immunocytochemical data In the present paper the autophagic vacuoles and autolysosomes involved in the digestion of excess peroxisomes are more extensively described, mainly by means of colloidal gold immunocytochemistry, carried out also on density gradient subfractions
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