Browsing by Subject "Autoradiography"
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- PublicationOpen AccessAn autoradiographic study of the uptake of tritiated proline by osteoblasts during hibernation(Murcia : F. Hernández, 1986) Steinberg, B.; Singh, I.J.; Mitchell, O.G.Twenty-four LSH and LVG strain golden hamsters, Mesocricetus auratus, were used. Experimental animals were maintained at 5 C and allowed to hibernate. Control animals were kept at 27 C. Six animals (3 experimental, 3 control) were injected subcutaneously with I pCi of 'H-proline/gm body wt. (Spec. act. 3 Ci/mM) after hibernation lasting 12 hours, I day, 3 days, or 7 days. Animals were killed I hour after injection and autoradiographs were prepared from 5 Frn thick ilecalcified sections of femurs. A greater number of endosteal cells were labeled than periosteal cells and also exhibited a greater magnitude of labeling throughout the study. Differences between endosteal and periosteal cells both in percentage of cells labeled and magnitude of labeling were maximum in control animals and progressively decreased with increasing periods of hibernation. A reduction in synthesis of matrix proteins during the early period of hibernation was seen and was attributed to a significant reduction both in average cell activity and in the number of active cells during hibernation. The latter phenomenon apparently made a large contribution to the reduced matrical synthesis. 'H-proline uptake by osteoblasts probably retlects the reduced requirements of matrical synthesis during hibernation.
- PublicationOpen AccessAutoradiographic investigation of circadian rhythms in alveolar bone periosteum and cementum in young mice(Murcia : F. Hernández, 1987) Tonna, E.A.; Singh, I.J.; Sandhu, H.S.This report presents circadian rhythms in cell proliferation of alveolar bone periosteum and cementum of the maxillary first molars of male 5-week-old BNL, Swiss albino mice which were maintained on a 12 hr light1 dark cycle. Mice were injected with 3H-TDR (lucilgm. body wt.) 1 hr prior to sacrifice and killed every 3 hrs for 24 hrs starting at 9 a.m. Maxillae were decalcified, routinely processed histologically and autoradiographs prepared. Cell labeling indices of alveolar bone and cementum mesial to the first molar were determined. Alveolar bone periosteal and cemental cells show circadian rhythm in their DNA synthetic processes. Peaks in percent labeling exhibit higher values than previously reported for nontraumatized, normal dental periosteum and cementum. While the outer periosteum reveals a single 24 hr peak (6 p.m.), inner periosteum and cementum reveal two ultradian peaks 9 to 12 hrs apart involving both light and dark periods. Rodents are nocturnal, but high peaks are also evident in the light periods, consequently, not all peaks are synonymous with the period of animal activity and feeding. Although the single daylight peak of the outer periosteum may indicate growth of that surface at night to about noon, the double peaks exhibited by inner periosteum and cementum indicate lightldark, continuously active surfaces in terms of DNA synthesis and growth
- PublicationOpen AccessAutoradiographic localization of estrogen target cells in the spinal cord of the armadillo and baboon, a comparative study(Murcia : F. Hernández, 1987) Weaker, Frank J.; Sheridan, Peter J.The uptake and retention of radiolabeled estradiol by the spinal cord were examined in the baboon and the armadillo and compared to previous observations in the rat. Four females of each species were injected intracardially with 1.0-1.4 pg/kg body weight of %- estradiol and two females, one baboon and one armadillo, were injected with both labeled and 100-140 pg/kg body weight of unlabeled estradiol. One hour after the injections, the animals were killed and segments from the cervical, thoracic, lumbar and sacral cord were removed and processed for autoradiography. In the armadillo, labeling of neuronal nuclei were noted in laminae I & I1 and in alpha motor neurons. In addition, nuclei of the ependymal cells of the ventral portion of the central canal in the cervical cord concentrated radioactivity. In contrast, the baboon demonstrated only sporadic labeling of neurons in lamina I1 in all levels of the spinal cord. The comparison of our observations with that of the rat suggest that estrogen mediated sensations are probably coordinated at higher brain centers in the primate as opposed to the more primitive mammals
- PublicationOpen AccessDistribution of vasoactive intestinal peptide and calcitonin gene-related peptide immunoreactive nerve fibers and binding sites in the hamster seminal vesicle during post-natal development(Murcia : F. Hernández, 1999) Afonso, F.; Pinho, M.S.; Fernandes, P.; Mata, L.R.; Gulbenkian, S.The distribution of vasoactive intestinal peptide (VIP)- and calcitonin gene-related peptide (CGRP)-immunoreactive nerves and 125~-labeledV IPand CGRP-binding sites was studied in the hamster seminal vesicle of 12-, 30- and 60-day-old animals. In addition, the general innervation of the seminal vesicle was examined using the general neuronal marker synaptophysin. Our results show that the densities of the overall (synaptophysin immunoreactive) and CGRP-immunoreactive innervation is constant during the post-natal development of the gland. However, a significant decrease in VIP-containing nerves is observed at the end of puberty. The autoradiographic study revealed that in 12-day-old animals, the epithelium presents VIP binding sites. However, in 30-day-old animals, VIP binding sites are observed in the epithelium of only a few clumps of acini. In 60-day-old animals, the gland is composed of acini with dilated lumina where VIP binding sites are not detected. In all groups studied the epithelium does not exhibit CGRP binding sites. The seminal vesicle muscle layer displays specific binding sites for both VIP and CGRP at all post-natal developmental times, but the density of VIP binding sites is higher in 12- than in 30- and 60-day-old animals. Our results, showing the presence of specific VIP and CGRP binding sites during the development of the hamster seminal vesicle, suggest that these neuropeptides may be involved in the growth and differentiation of the gland.
- PublicationOpen AccessDNA synthesis in the embryonic chick lens epithelium ¡S arrested after experimental lens rotation(Murcia : F. Hernández, 1994) Prada, F. A.; Garcia-Lomas, V.; Genís-Gálvez, J. M.Using autoradiographic technique, we have studicd DNA synthesis in normal embryonic chick lens epitheliuni and after experimental lens rotation. Analysis of the autoradiograms clearly demonstrates that when the lens priniordium was rotated 180". so that lens epithelium was placed facing the interior of the optic cup. the lens epithelial cells completely stop DNA synthesis. This fact suggests that some retinal and vitieal factors are responsible for differentiation and replicative capacity of the lens epithelial cells.
- PublicationOpen AccessExpression of gonadotrophin-releasing hormone binding sites in somatic tissues of the gilthead seabream (Sparus aurata): a quantitative autoradiographic study(Murcia : F. Hernández, 2006) González-Martínez, D.; Sarasquete, C.; Pascual, E.; Muñoz-Cueto, J.A.In this study, we have analysed the expression of gonadotrophin-releasing hormone (GnRH) binding sites in somatic tissues (intestine, liver, gill, skeletal muscle, ovary, heart, stomach, kidney and spleen) of the gilthead seabream, Sparus aurata using 3- [125I]iodototyrosyl5-mammalian GnRH and autoradiographic techniques. The qualitative and quantitative analysis showed the existence of a basal expression of specific GnRH binding sites in intestine, skeletal muscle, ovary, stomach and spleen. Furthermore, our data suggest that the level of expression of GnRH binding sites can be significantly enhanced by GnRH treatment in intestine, gill, heart, stomach, kidney and spleen. This study shows that GnRH can exert direct effects in both reproductive and non-reproductive somatic tissues of the gilthead seabream.
- PublicationOpen AccessFine autoradiographical study on scale morphogenesis in the regenerating tail of lizards(Murcia : F. Hernández, 1994) Alibardi, LorenzoRegenerating scales in lizards originate as pockets in the epidermis instead of epidermal elevations as during embryo development. The morphogenesis of scales in the regenerating tail of the lizards. Anolis and Lamphropholis was studied after peritoneal injection of 3~-thymidineT. he tracer was localized in the forming epidermis after progressive post-injection times, by means of autoradiographY on plastic sections. After 4-5 hours post-injection of H-thymidine, the radioactivity was localized in the basal layer. After 2 to 4 days postinjection labelled cells were seen in the basal and intermediate spinosus layers but not in the uppermost keratinizing layers. Labelled cells were seen in the differentiating cornifying layers (pre-B and pre-a) 6-8 days post-injection. At 12-14 days post-injection almost no radioactivity was seen in the basal layer or in the living part of the epidermis. A few labelled cells were present in the dense keratinizing layers of the sloughing wound and interscale lacunar layers. This study shows that scale formation and morphogenesis in the regenerating tail is brought about by a localized cell proliferation along the regenerating epidermis. In the forming scales the percentage of labelled cells in the distal side (future dorsal part of the new scale) is much higher than in the proximal side (the future ventral side of the scale), so that overlapped scales are generated.
- PublicationOpen AccessLocation of Zinc and 65Zn in spinal ganglia of the rat(Murcia : F. Hernández, 2002) Perez-Castejon, M.C.; Vera-Gil, A.; Lahoz, M.; Aisa, J.; Recreo, M.P.; Pes, N.; Serrano, P.; Barral, M.J.Following the works of Velazquez et al. (1999), Jo-Seung et al. (2000), Wang et al. (2001), Danscher et al. (2001) and the criteria of Zinc-containing neurons established by Frederickson et al.(2000), we have found the presence and localisation of Zinc in the neurons of the dorsal root ganglia of Wistar rat, by using Timm’s thecnique and by studying the autoradiographic uptake of 65Zn. The agreement between the results of both techniques allows us to classify these spinal ganglion neurons as Zinc-containing neurons and also, to confirm some of the results of Velazquez et al. (1999)