Prisutnost imunoreaktivnih ciklooksigenaza u sjemenskim kanalićima i nuzjajima u alpaka prije spolne zrelosti i odraslih alpaka (Lama pacos).

In this study, we report the cell specific expression of cyclooxygenase (COX) enzymes, COX1 and COX2, in the ductuli efferentes and epididymis of prepubertal and adult alpaca. COX1 weakly stained the cytoplasm of epithelial cells lining the ductuli efferentes and the epididymal corpus, whereas these cells were immunonegative in the epididymal caput and cauda. In adults, we observed an increase in the immunsignals for COX1 in the cytoplasm of epithelial cells lining the ductuli efferentes and all the epididymal regions. In prepubertal alpaca, immunoreactivity for COX2 was not revealed in the epithelial cells lining the ductuli efferentes and epididymal regions, whereas it was evidenced in adult animals. The apical rich mithocondria cells immunoreacted only with COX1 in the epididymis of prepubertal animals, whereas they expressed both COX1 and -2 in the adult alpaca. Our results suggest that COXs may play a role in the pubertal development of the excurrent duct system of the alpaca.Istražena je stanično specifična ekspresija enzima ciklooksigenaza COX1 i COX2 u sjemenim kanalićima i nuzjaju u alpaka prije spolne zrelosti i odraslih alpaka. Slaba aktivnost COX1 dokazana je u citoplazmi epitelnih stanica sjemenih kanalića i tijela nuzjaja dok su iste stanice bile imunološki negativne u glavi i repu nuzjaja. U odraslih je opaženo povećanje imunosnog signala za COX1 u citoplazmi bazalnih epitelnih stanica sjemenih kanalića i cijelog područja nuzjaja. U alpaka prije spolne zrelosti, imunoreaktivnost za COX2 se nije vidjela u epitelnim stanicama sjemenih kanalića i nuzjajima kao što je to bilo kod odraslih životinja. Apikalne stanice bogate mitohondrijima reagirale su samo na COX1 u nuzjajima životinja prije spolne zrelosti dok je ekspresija i COX1 i COX2 opažene u odraslih alpaka. Rezultati ukazuju na moguću ulogu ciklooksigenaza u razvoju razgranatog sustava kanalića prije spolne zrelosti u alpaka

Dopamine receptors and transporters sensitivity to trimethyltin in rat hippocampus and facial nucleus

Trimethyltin (TMT) is considered a useful tool to obtain an experimental model of neurodegeneration. TMT is known to cause neurotoxicant effects especially marked in the hippocampus. Despite many studies are published, there are poor literature on the interaction of this xenobiotic with dopaminergic system. In the present work, we investigate in rat brain, after 21 days following TMT intraperitoneal administration, the cells viability (N-NEU) and the animal behaviour in association with the immunohystochemical expression of dopamine receptors (D1- and D2-like) and transporters membrane (DAT) and vesicular monoamine trasporters (VMAT-1 and -2) in rat hippocampus and facial nucleus. The animal behaviour shows a significant reduction of spatial reference memory in a Morris water maze task according with the reduction (70% Vs control) of hippocampus dopaminergic system expression, despite the cell viability is maintained at about 50%. In the facial nucleus, a different reduction of dopamine receptors and trasporters (30% against 60%) was observed while the N-NEU reduction was 40%. These results suggest that the toxic interaction of TMT with the dopaminergic system in rat hippocampus may be responsible for learning and memory deficits. Data obtained in facial nucleus demonstrate different sensitivity of dopamine receptors and dopamine transporters to xenobiotic. Supported by PRIN 2008 - prot. 20089MANHH_00