86,603 research outputs found
Expression of Orexin A and its receptors in the porcine ovary
No full text4.4 Expression of Orexin A and its receptors in the porcine ovary
Ragionieri L., Ravanetti F., Botti M., Ciccimarra R., Bussolati S., Basini G., Gazza F., and Cacchioli A.
Department of Veterinary Sciences, University of Parma.
Orexin A (OXA), and B are two neuropeptides mainly synthesized in the lateral hypothalamus, from a common precursor called prepro-orexin and involved in different functions such as regulation of food intake, energy balance, reproductive activities, sleep and wakefulness. Their action is mediated by binding G-protein-coupled receptors, termed orexin receptor 1 (OXR1) and orexin receptor 2 (OXR2). As orexins and their receptors were previously described also in different tissues and organs outside the brain, we investigated their presence in the porcine ovary. Using double labelling immunofluorescence techniques, we observed OXA and its receptors in granulosa, thecal and luteal cells, moreover in corpora albicantia, atretic follicles and interstitial cells of the porcine ovary. These last three localizations had never been investigated in previous research. OXA and OXR2 appeared more diffused in the cytoplasm and OXR1 associated to the nuclear envelop of the granulosa cells, while in thecal, luteal and interstitial cells, all the substances appeared associated to cytoplasmic vesicles. We also proved, by real-time Polymerase-Chain-Reaction, that granulosa cells of large follicles and luteal cells express the prepro-orexin gene. In vitro administration of OXA stimulated the growth and induced an increased production of oestradiol in granulosa cells. The progesterone production was instead not affected in granulosa cells, while inhibited in luteal cells. Taken together these findings demonstrate that porcine ovary contains different cells types able to secrete and/or internalize OXA, thus suggesting both autocrine and paracrine modalities of action of OXA. Moreover, OXA could be involved in modulating ovarian steroidogenesis and follicle growth
Human Vitronectin-Derived Peptide Covalently Grafted onto Titanium Surface Improves Osteogenic Activity: A Pilot In Vivo Study on Rabbits
No full textPeptide and protein exploitation for the biochemical functionalization of biomaterial surfaces allowed fabricating
biomimetic devices able to evoke and promote specific and advantageous cell functions in vitro and in vivo. In
particular, cell adhesion improvement to support the osseointegration of implantable devices has been thoroughly
investigated. This study was aimed at checking the biological activity of the (351–359) human vitronectin precursor
(HVP) sequence, mapped on the human vitronectin protein; the peptide was covalently linked to the
surface of titanium cylinders, surgically inserted in the femurs of New Zealand white rabbits and analyzed at short
experimental time points (4, 9, and 16 days after surgery). To assess the osteogenic activity of the peptide, three
vital fluorochromic bone markers were used (calcein green, xylenol orange, and calcein blue) to stain the areas of
newly grown bone. Static and dynamic histomorphometric parameters were measured at the bone–implant
interface and at different distances from the surface. The biological role of the (351–359)HVP sequence was
checked by comparing peptide-grafted samples and controls, analyzing how and how much its effects change
with time across the bone regions surrounding the implant surface. The results obtained reveal a major activity of
the investigated peptide 4 days after surgery, within the bone region closest to the implant surface, and larger bone
to implant contact 9 and 16 days after surgery. Thus, improved primary fixation of endosseous devices can be
foreseen, resulting in an increased osteointegration
Background-free Detection of Mouse Antibodies on Mouse Tissue by Anti-isotype Secondary Antibodies
No full textImmunodetection on mouse routinely processed tissue via antibodies raised in mice faces cross-reactivity of the secondary anti-mouse reagents with endogenous immunoglobulins, which permeate the tissue. Various solutions to this problem have been devised and include endogenous Ig block with anti-mouse Fab fragments or directly conjugated primary antibodies. Mouse isotype-specific antibodies, differently from reagents directed against both heavy and light chains, fail to detect endogenous Ig after fixation and embedding, while providing a clean and specific detection system for mouse antibodies on mouse routinely processed tissue
Studio istomorfometrico dell'attività osteogenica indotta dalla funzionalizzazione del titanio con il peptide HVP(351-359)
No full textPreliminary study on the mineral apposition rate in distal femoral epiphysis of New Zealand White Rabbit at skeletal maturity
No full textStudies investigating the effect of different factors on the skeletal system require characterization of an appropriate animal model. Rabbits are among the most commonly studied animals for medical research, being used in about 35% of musculoskeletal research studies. The present dynamic cross-sectional histomorphometric study quantitatively determined mineral apposition rates (MARs) in the distal femoral epiphysis in four regions of interest (ROIs) in New Zealand white rabbits. ROIs included the craniolateral (CrL), caudolateral (CaL), craniomedial (CrM) and caudomedial (CaM) areas, using a reference height at different stages of skeletal maturity corresponding to experimental ages of 6, 7 and 8 months old (M6, M7 and M8). We evaluated whether a correlation exists in MARs between the times and the regions examined. Such data could be used in studies on growth of the rabbit’s femur, on biomaterials for bone integration or regeneration and on growth disturbances produced by various pathologic factors. We found no interaction at the experimental times; thus, M6, M7 and M8 are considered homogeneous in terms of MARs. The velocity profiles of the MARs were statistically significantly different among the considered ROIs. For all experimental times, the CrM region had a higher MAR than the other ROIs. Both the CrM and CaM ROIs had higher MARs than the corresponding lateral ROIs. Our results indicate that bone formation is not constant within the cross-section, but is statistically different between the ROIs considered
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