Administration Of 5-bromodeoxyuridine Research Articles

Growth hormone (GH) treatment may cooperate with locally-produced GH in increasing the proliferative response of hippocampal progenitors to kainate-induced injury

Primary objective: This study was designed to investigate the effect of growth hormone treatment on the proliferation of endogenous neural progenitor cells in the dentate gyrus (DG) of the brain stimulated by kainic acid (KA)-induced neurotoxicity.Research design: Neurotoxicity was induced by intraperitoneal injection of KA. GH treatment lasted 4 days, starting either immediately or after 10 days of administration of the neurotoxic insult.Methods and procedure: Proliferating cells were immunodetected after labelling by in vivo administration of 5-bromodeoxyuridine (BrdU). GH expression was detected by in situ hybridization and immunofluorescence.Main outcomes and results: KA administration stimulated the proliferation of hippocampal precursors and this effect was significantly enhanced by GH treatment. Hippocampal GH expression was also up-regulated in response to KA administration.Conclusions: The findings support the possibility that the proliferative response observed in the hippocampus of rats treated with KA and GH is a consequence of cooperation between the exogenous and the locally-produced hormone and their synergism with other mitogenic factors generated in response to the neurotoxic damage. Therefore, GH treatment could be used to cooperate with other physiological or pathological stimuli in order to promote cell proliferation.

Analysis of cerebrocortical neuronal migration in three-dimensional fetal mouse cerebral explants: comparison with in vivo

Organotypic cultures of cerebral mantle offer a useful method for in vitro investigation of mechanisms involved in the migration of neuronal precursors to the neocortex. Studies reported to-date have indicated that, while neurons continue to migrate in cerebral explant cultures for a few days, they eventually stop migrating and fail to reach their pre-programmed destinations and thus distinct layers fail to develop within the cortical plate. Hypothesizing that this migrational arrest stemmed, in part, from severe distortion and flattening of explants in the roller-tube culture method used in previous studies by others, we studied neocortical neuronal migration using a recently developed three-dimensional explant culture system. Explants 300–350 μm thick were derived from E16 fetal mouse cerebrum 24 h following administration of 5-bromodeoxyuridine (BrdU), encased in collagen, placed on porous membranes, and alternately exposed to medium and air on a rocking platform. Cultures were maintained for 7, 11 and 14 days, then analyzed for the location of BrdU-labeled cells. Newborn mice labeled at E15 and analyzed at P1 and P9 served as controls. In the explants, labeled cells continued to migrate into the cortical plate until 11 days in culture, at which point the ventricular zone had disappeared and two distinct cortical cell layers sometimes developed. BrdU-labeled cells were present throughout the cortical plate, particularly the mid portion. In P9 controls, five distinct cortical layers were present with labeled cells mostly in the outer half (layers II, III). Thus, preservation of three-dimensional tissue integrity in culture was accompanied by a modest improvement in migration of neurons to the neocortex in comparison with previous reports. The fact that normal layer formation failed to develop in thick explants suggests that factors other than tissue distortion contribute to this outcome.

Estimation of the duration of the cycle of the seminiferous epithelium in the non-human primate Macaca mulatta using the 5-bromodeoxyuridine technique.

A comparatively low yield of germ cells has been reported for the spermatogenic process in primates. Kinetic studies of spermatogenesis and the spermatogenic cycle are needed to investigate this phenomenon but require the application of radioactively labeled compounds or irradiation. We have therefore investigated the suitability of a non-radioactive approach, viz., administration of 5-bromodeoxyuridine, for the determination of the kinetics of the spermatogenic cycle in a non-human primate, the rhesus monkey (Macaca mulatta). Four adult in-season animals received a bolus of 33 mg/kg 5-bromodeoxyuridine, one testis from each monkey was removed 3 h later and the other testis after 10 days and 11 h. Tissue was fixed in Bouin's solution and embedded in Paraplast. 5-Bromodeoxyuridine was localized by immunogold-silver staining with a monoclonal antibody. PAS-hematoxylin counterstaining was used for spermatogenic stage identification. At 3 h, the leptotene and zygotene spermatocytes in stages VII-IX were the most advanced 5-bromodeoxyuridine-positive cells. At 10 days 11 h, the label had advanced and pachytene spermatocytes in stages VI-IX contained 5-bromodeoxyuridine. The duration of the spermatogenic cycle was 10.42+/-0.07 days (range: 10.25-10.62 days). Peritubular cells and interstitial cells were rarely 5-bromodeoxyuridine-positive, and Sertoli cells were consistently negative for 5-bromodeoxyuridine. Importantly, our kinetic data closely resemble those obtained by means of the application of irradiation for this macaque species. We conclude that administration of 5-bromodeoxyuridine represents a non-radioactive reliable approach for studying kinetic aspects of the spermatogenic process in primates.