TRY plant trait database – enhanced coverage and open access

Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

TRY plant trait database – enhanced coverage and open access

Plant traits—the morphological, anatomical, physiological, biochemical and phenological characteristics of plants—determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits—almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives.Rest of authors: Decky Junaedi, Robert R. Junker, Eric Justes, Richard Kabzems, Jeffrey Kane, Zdenek Kaplan, Teja Kattenborn, Lyudmila Kavelenova, Elizabeth Kearsley, Anne Kempel, Tanaka Kenzo, Andrew Kerkhoff, Mohammed I. Khalil, Nicole L. Kinlock, Wilm Daniel Kissling, Kaoru Kitajima, Thomas Kitzberger, Rasmus Kjøller, Tamir Klein, Michael Kleyer, Jitka Klimešová, Joice Klipel, Brian Kloeppel, Stefan Klotz, Johannes M. H. Knops, Takashi Kohyama, Fumito Koike, Johannes Kollmann, Benjamin Komac, Kimberly Komatsu, Christian König, Nathan J. B. Kraft, Koen Kramer, Holger Kreft, Ingolf Kühn, Dushan Kumarathunge, Jonas Kuppler, Hiroko Kurokawa, Yoko Kurosawa, Shem Kuyah, Jean-Paul Laclau, Benoit Lafleur, Erik Lallai, Eric Lamb, Andrea Lamprecht, Daniel J. Larkin, Daniel Laughlin, Yoann Le Bagousse-Pinguet, Guerric le Maire, Peter C. le Roux, Elizabeth le Roux, Tali Lee, Frederic Lens, Simon L. Lewis, Barbara Lhotsky, Yuanzhi Li, Xine Li, Jeremy W. Lichstein, Mario Liebergesell, Jun Ying Lim, Yan-Shih Lin, Juan Carlos Linares, Chunjiang Liu, Daijun Liu, Udayangani Liu, Stuart Livingstone, Joan Llusià, Madelon Lohbeck, Álvaro López-García, Gabriela Lopez-Gonzalez, Zdeňka Lososová, Frédérique Louault, Balázs A. Lukács, Petr Lukeš, Yunjian Luo, Michele Lussu, Siyan Ma, Camilla Maciel Rabelo Pereira, Michelle Mack, Vincent Maire, Annikki Mäkelä, Harri Mäkinen, Ana Claudia Mendes Malhado, Azim Mallik, Peter Manning, Stefano Manzoni, Zuleica Marchetti, Luca Marchino, Vinicius Marcilio-Silva, Eric Marcon, Michela Marignani, Lars Markesteijn, Adam Martin, Cristina Martínez-Garza, Jordi Martínez-Vilalta, Tereza Mašková, Kelly Mason, Norman Mason, Tara Joy Massad, Jacynthe Masse, Itay Mayrose, James McCarthy, M. Luke McCormack, Katherine McCulloh, Ian R. McFadden, Brian J. McGill, Mara Y. McPartland, Juliana S. Medeiros, Belinda Medlyn, Pierre Meerts, Zia Mehrabi, Patrick Meir, Felipe P. L. Melo, Maurizio Mencuccini, Céline Meredieu, Julie Messier, Ilona Mészáros, Juha Metsaranta, Sean T. Michaletz, Chrysanthi Michelaki, Svetlana Migalina, Ruben Milla, Jesse E. D. Miller, Vanessa Minden, Ray Ming, Karel Mokany, Angela T. Moles, Attila Molnár V, Jane Molofsky, Martin Molz, Rebecca A. Montgomery, Arnaud Monty, Lenka Moravcová, Alvaro Moreno-Martínez, Marco Moretti, Akira S. Mori, Shigeta Mori, Dave Morris, Jane Morrison, Ladislav Mucina, Sandra Mueller, Christopher D. Muir, Sandra Cristina Müller, François Munoz, Isla H. Myers-Smith, Randall W. Myster, Masahiro Nagano, Shawna Naidu, Ayyappan Narayanan, Balachandran Natesan, Luka Negoita, Andrew S. Nelson, Eike Lena Neuschulz, Jian Ni, Georg Niedrist, Jhon Nieto, Ülo Niinemets, Rachael Nolan, Henning Nottebrock, Yann Nouvellon, Alexander Novakovskiy, The Nutrient Network, Kristin Odden Nystuen, Anthony O'Grady, Kevin O'Hara, Andrew O'Reilly-Nugent, Simon Oakley, Walter Oberhuber, Toshiyuki Ohtsuka, Ricardo Oliveira, Kinga Öllerer, Mark E. Olson, Vladimir Onipchenko, Yusuke Onoda, Renske E. Onstein, Jenny C. Ordonez, Noriyuki Osada, Ivika Ostonen, Gianluigi Ottaviani, Sarah Otto, Gerhard E. Overbeck, Wim A. Ozinga, Anna T. Pahl, C. E. Timothy Paine, Robin J. Pakeman, Aristotelis C. Papageorgiou, Evgeniya Parfionova, Meelis Pärtel, Marco Patacca, Susana Paula, Juraj Paule, Harald Pauli, Juli G. Pausas, Begoña Peco, Josep Penuelas, Antonio Perea, Pablo Luis Peri, Ana Carolina Petisco-Souza, Alessandro Petraglia, Any Mary Petritan, Oliver L. Phillips, Simon Pierce, Valério D. Pillar, Jan Pisek, Alexandr Pomogaybin, Hendrik Poorter, Angelika Portsmuth, Peter Poschlod, Catherine Potvin, Devon Pounds, A. Shafer Powell, Sally A. Power, Andreas Prinzing, Giacomo Puglielli, Petr Pyšek, Valerie Raevel, Anja Rammig, Johannes Ransijn, Courtenay A. Ray, Peter B. Reich, Markus Reichstein, Douglas E. B. Reid, Maxime Réjou-Méchain, Victor Resco de Dios, Sabina Ribeiro, Sarah Richardson, Kersti Riibak, Matthias C. Rillig, Fiamma Riviera, Elisabeth M. R. Robert, Scott Roberts, Bjorn Robroek, Adam Roddy, Arthur Vinicius Rodrigues, Alistair Rogers, Emily Rollinson, Victor Rolo, Christine Römermann, Dina Ronzhina, Christiane Roscher, Julieta A. Rosell, Milena Fermina Rosenfield, Christian Rossi, David B. Roy, Samuel Royer-Tardif, Nadja Rüger, Ricardo Ruiz-Peinado, Sabine B. Rumpf, Graciela M. Rusch, Masahiro Ryo, Lawren Sack, Angela Saldaña, Beatriz Salgado-Negret, Roberto Salguero-Gomez, Ignacio Santa-Regina, Ana Carolina Santacruz-García, Joaquim Santos, Jordi Sardans, Brandon Schamp, Michael Scherer-Lorenzen, Matthias Schleuning, Bernhard Schmid, Marco Schmidt, Sylvain Schmitt, Julio V. Schneider, Simon D. Schowanek, Julian Schrader, Franziska Schrodt, Bernhard Schuldt, Frank Schurr, Galia Selaya Garvizu, Marina Semchenko, Colleen Seymour, Julia C. Sfair, Joanne M. Sharpe, Christine S. Sheppard, Serge Sheremetiev, Satomi Shiodera, Bill Shipley, Tanvir Ahmed Shovon, Alrun Siebenkäs, Carlos Sierra, Vasco Silva, Mateus Silva, Tommaso Sitzia, Henrik Sjöman, Martijn Slot, Nicholas G. Smith, Darwin Sodhi, Pamela Soltis, Douglas Soltis, Ben Somers, Grégory Sonnier, Mia Vedel Sørensen, Enio Egon Sosinski Jr, Nadejda A. Soudzilovskaia, Alexandre F. Souza, Marko Spasojevic, Marta Gaia Sperandii, Amanda B. Stan, James Stegen, Klaus Steinbauer, Jörg G. Stephan, Frank Sterck, Dejan B. Stojanovic, Tanya Strydom, Maria Laura Suarez, Jens-Christian Svenning, Ivana Svitková, Marek Svitok, Miroslav Svoboda, Emily Swaine, Nathan Swenson, Marcelo Tabarelli, Kentaro Takagi, Ulrike Tappeiner, Rubén Tarifa, Simon Tauugourdeau, Cagatay Tavsanoglu, Mariska te Beest, Leho Tedersoo, Nelson Thiffault, Dominik Thom, Evert Thomas, Ken Thompson, Peter E. Thornton, Wilfried Thuiller, Lubomír Tichý, David Tissue, Mark G. Tjoelker, David Yue Phin Tng, Joseph Tobias, Péter Török, Tonantzin Tarin, José M. Torres-Ruiz, Béla Tóthmérész, Martina Treurnicht, Valeria Trivellone, Franck Trolliet, Volodymyr Trotsiuk, James L. Tsakalos, Ioannis Tsiripidis, Niklas Tysklind, Toru Umehara, Vladimir Usoltsev, Matthew Vadeboncoeur, Jamil Vaezi, Fernando Valladares, Jana Vamosi, Peter M. van Bodegom, Michiel van Breugel, Elisa Van Cleemput, Martine van de Weg, Stephni van der Merwe, Fons van der Plas, Masha T. van der Sande, Mark van Kleunen, Koenraad Van Meerbeek, Mark Vanderwel, Kim André Vanselow, Angelica Vårhammar, Laura Varone, Maribel Yesenia Vasquez Valderrama, Kiril Vassilev, Mark Vellend, Erik J. Veneklaas, Hans Verbeeck, Kris Verheyen, Alexander Vibrans, Ima Vieira, Jaime Villacís, Cyrille Violle, Pandi Vivek, Katrin Wagner, Matthew Waldram, Anthony Waldron, Anthony P. Walker, Martyn Waller, Gabriel Walther, Han Wang, Feng Wang, Weiqi Wang, Harry Watkins, James Watkins, Ulrich Weber, James T. Weedon, Liping Wei, Patrick Weigelt, Evan Weiher, Aidan W. Wells, Camilla Wellstein, Elizabeth Wenk, Mark Westoby, Alana Westwood, Philip John White, Mark Whitten, Mathew Williams, Daniel E. Winkler, Klaus Winter, Chevonne Womack, Ian J. Wright, S. Joseph Wright, Justin Wright, Bruno X. Pinho, Fabiano Ximenes, Toshihiro Yamada, Keiko Yamaji, Ruth Yanai, Nikolay Yankov, Benjamin Yguel, Kátia Janaina Zanini, Amy E. Zanne, David Zelený, Yun-Peng Zhao, Jingming Zheng, Ji Zheng, Kasia Ziemińska, Chad R. Zirbel, Georg Zizka, Irié Casimir Zo-Bi, Gerhard Zotz, Christian Wirth.Max Planck Institute for Biogeochemistry; Max Planck Society; German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig; International Programme of Biodiversity Science (DIVERSITAS); International Geosphere-Biosphere Programme (IGBP); Future Earth; French Foundation for Biodiversity Research (FRB); GIS ‘Climat, Environnement et Société'.http://wileyonlinelibrary.com/journal/gcbhj2021Plant Production and Soil Scienc

Investigação da qualidade da microarquitetura óssea em função do uso prolongado de alta dose de tibolona através de técnicas de imagens

A osteoporose é uma das doenças ósseas mais comuns, especialmente durante o climatério. Como consequência do envelhecimento da população mundial, a incidência da osteoporose irá inevitavelmente aumentar ano a ano. A tibolona é um esteroide sintético utilizado como terapia de reposição hormonal para mulher posmenopausada e pode efetivamente prevenir a perda de osso trabecular através da redução da reabsorção óssea. Mesmo com eficácia comprovada, a tibolona assim como outras TRHs vêm sendo recomendadas em menores dosagens por motivos de segurança. O nosso interesse está em contribuir no entendimento dos efeitos da tibolona na qualidade óssea em um tratamento de longa duração com alta dosagem, inseridos no protocolo experimental proposto nesse estudo. Este experimento foi realizado em um grupo de ratas não ovariectomizadas (C, n=5) e três grupos previamente ovariectomizados. Um grupo recebeu tibolona (OVX+T, n=9) enquanto os outros não (OVX+150d, n=6 e OVX+30d, n=6). Após 30 dias da cirurgia, somente as ratas do grupo OVX+30d foram eutanasiadas e os fêmures coletados. A administração de tibolona (1mg/dia) começou 30 dias após a OVX e perdurou por 150 dias. Ao final do experimento, todos os animais foram mortos e os fêmures coletados. A microfluorescência de raios X foi utilizada para investigar a distribuição de cálcio e zinco na região trabecular da cabeça femoral. A microtomografia computadorizada analisou o percentual de volume ósseo (BV/TV), porosidade, número trabecular (TbN), separação trabecular (Tb.Sp) e espessura trabecular (Tb.Th) em cabeça, colo e trocanter femoral antes e depois da análise mecânica que avaliou a resistência óssea. Os dados foram estatisticamente avaliados com significância estabelecida em P<0,05%. Os resultados apenas dos grupos castrados sem tibolona (OVX+30d e OVX+150d) comparados com o grupo C demonstraram que a indução da perda óssea nos ratos ocorreu em ambos os grupos porém apenas 150 dias após a cirurgia foram suficientes para provocar uma perda óssea significativa. Os resultados para cada grupo foram similares antes e após o ensaio mecânico. O grupo OVX+150d apresentou uma significativa diminuição da massa óssea e de sua rigidez em relação ao grupo C. Mesmo sem diferença estatística na maioria dos parâmetros analisados, o tratamento com tibolona (OVX+T) preservou a massa óssea trabecular, demonstrando alguns resultados similares ao grupo C, o qual apresentou um aumento significativo de BV/TV em relação ao grupo OVX+150d na cabeça femoral direita e região trocantérica, além de maior TbN em colo e trocanter femoral. O grupo OVX+150d apresentou uma diminuição significativa na concentração de Zn na cabeça femoral comparado ao grupo C. A administração prolongada de tibolona em alta dosagem não prejudicou a microarquitetura óssea nas regiões analisadas e preservou a massa óssea na região trabecular do fêmur proximal, prevenindo a indução de perda óssea e uma maior deterioração da microarquitetura trabecular pela supressão do turnover ósseo. Finalmente, a nova abordagem nesse protocolo experimental e respectivos resultados orientam que cuidados devem ser tomados em relação aos protocolos de reposição hormonal disponíveis, já que as mulheres atualmente estão passando mais tempo de suas vidas utilizando hormônios devido à períodos mais prolongados de pós menopausaO presente trabalho foi realizado com apoio do Conselho Nacional de Desenvolvimento Científico e TecnológicoOsteoporosis is one of the most common diseases of bone, especially in elderly women, due to estrogen deficiency during the climacteric. As a consequence of world´s population aging, the incidence of osteoporosis will, inevitably, increase year by year. Tibolone is a synthetic steroid used in hormonal replacement therapy for postmenopausal women and can effectively prevent trabecular bone loss by reducing bone resorption. Despite with proven effectiveness, tibolone and other HRTs are recommended in lower doses for safety reasons. Our interest is to contribute to the understanding of tibolone effects on bone quality under long-term treatment using a high dosage, inserted in the experimental protocol proposed in this study. This experiment was performed in one group of rats non-ovariectomized (C, n=5) and three groups previously ovariectomized. One group received tibolone (OVX+T, n=9) while the others did not (OVX+150d, n=6 and OVX+30d, n=6). After 30 days of surgery, only rats from the OVX+30d group were euthanized and femurs were collected. Tibolone administration (1mg/day) began 30 days after ovariectomy, remaining for 150 days. At the end of the experiment, all the animals were euthanized and femurs were collected. X-Ray Microfluorescence was used to investigate the distribution of calcium and zinc on trabecular region of femoral head. Microcomputed tomography analyzed bone volume percentage (BV/TV), porosity, trabecular number (Tb.N), trabecular separation (Tb.Sp) and trabecular thickness (Tb.Th) at femoral head, femoral neck and trochanter before and after the mechanical analysis which analyzed bone stiffness. Data were statistically evaluated with significance set at P<0.05%. Results only from castrated groups without tibolone (OVX+30d e OVX+150d) compared to C group show that the induction of bone loss in rats occurs in both groups, but only 150 days after surgery were sufficient to provide significant bone loss. The results for each group were similar before and after the mechanical test. The OVX+150d group presented significant lower bone mass and stiffness than the C group. Even without statistical diference in most of the parameters analyzed, tibolone treatment (OVX+T) preserved trabecular bone mass, showing some similar results to C group, which presented significant higher BV/TV than OVX+150d group in the right femoral head and trochanteric region, and higher TbN in femoral neck and trochanter. The OVX+150d group showed a significant lower concentration of Zn on femoral head compared to C group. Prolonged administration of tibolone in high dosage did not damage the bone microarchitecture in the analyzed regions and preserved bone mass in the trabecular region of proximal femur, preventing bone loss and a greater deterioration of trabecular microarchitecture probably by suppressing bone turnover. As a final point, the new approach in this experimental protocol and our results warn that care must be taken with available hormone replacement protocols since currently women spend longer time using hormones due to a prolonged period of post-menopause.118f

Efeito da tibolona sobre o endométrio de ratas castradas Effect of tibolone on endometrium of castrated rats

OBJETIVO: avaliar o efeito do uso prolongado de alta dose de tibolona na morfologia do endométrio em ratas castradas. MÉTODOS: foram utilizadas 15 ratas Wistar, fêmeas, com idade de oito semanas e peso médio de 250 g. Todas as ratas foram submetidas à ooforectomia bilateral e 30 dias depois foi coletada citologia vaginal, verificando-se o status de menopausa. As ratas foram divididas aleatoriamente em dois grupos: o tratado (n=9) recebeu via oral 1 mg tibolona/dia; o controle (n=6) recebeu apenas solução do veículo carboximetilcelulose. Após 20 semanas de tratamento, todos os animais foram sedados e sacrificados por deslocamento cervical. Os úteros foram retirados e fixados em formol 10% tamponado. Ambos os cornos uterinos foram clivados em três regiões (proximal, medial, distal) e processados para inclusão em parafina. Cortes histológicos corados com hematoxilina-eosina foram submetidos à análise morfológica e morfométrica. Foram avaliados os seguintes parâmetros: espessura do epitélio superficial endometrial, espessura do estroma endometrial, área endometrial, número absoluto de glândulas endometriais e número de glândulas/área endometrial. Os dados obtidos foram comparados mediante o teste t de Student. RESULTADOS: no Grupo Tibolona os úteros se apresentaram bem desenvolvidos e houve aumento significativo (pPURPOSE: to evaluate the effect of long-term use of a high dose of tibolone on the morphology of the endometrium of castrated female rats. METHODS: fifteen female Wistar rats, aged eight weeks and weighting about 250 g were used. All the female rats were submitted to bilateral oophorectomy and 30 days afterwards, vaginal cytology was collected, to verify the menopause status. The female rats were randomly divided in two groups. The Treatment Group (n=9) received 1 mg of tibolone/day orally; the Control Group (n=6) received a solution of carboxymethylcellulose vehicle. After 20 weeks of treatment, all the animals were sedated and sacrificed by cervical dislocation. The uterus was removed and fixated in 10% buffer formaldehyde. Both uterine horns were divided in three regions (proximal, medial and distal) and processed to be included in paraffin. Histological sections, stained with hematoxylin-eosin were submitted to morphological and morphometrical analysis. The following parameters have been analyzed: thickness of the endometrial superficial epithelium, thickness of the endometrium stroma, endometrial area, absolute number of endometrial glands and number of glands/endometrial area. The data obtained were compared by the t-Student test. RESULTS: in the Tibolone Group, the uteri were well developed and there was a significant increase (p<0.01) of all the histomorphometric parameters. In some cases, the cylindrical epithelium became stratified, pavimentous and covered the internal portions of the glands, as well as of the endometrium cavity. Rats from the Control Group presented uterine atrophy. There were few tubular-like glands and scarce intercellular substance. Glands were covered by cubic epithelium which extended itself to the endometrial cavity. CONCLUSIONS: high doses of tibolone, given for long periods of time to castrated female rats, have an estrogenic effect which can be dose-dependent, causing proliferation in the endometrium and causing changes in the cell differentiation (squamous metaplasia), but do not lead to hyperplasia

Histomorfometria do tecido ósseo em ratas castradas tratadas com tibolona

INTRODUÇÃO E OBJETIVO: O efeito da tibolona utilizada em alta dose e por tempo prolongado foi analisado mediante estudo histomorfométrico de tíbias e fêmures de ratas castradas. MÉTODOS: O experimento utilizou 20 ratas Wistar, com peso médio de 250 g. Os animais foram distribuídos aleatoriamente em três grupos: ooforectomizado recebendo tibolona (OVX + T) (n = 9), ooforectomizado (OVX) (n = 6) e grupo controle não ooforectomizado (C) (n = 5). Deu-se início ao protocolo experimental 30 dias após a ooforectomia, perdurando por 20 semanas, com administração de tibolona (1 mg/dia) a OVX + T e carboximetilcelulose a OVX. O grupo C não foi submetido a qualquer tratamento. Tíbias e fêmures direitos foram fixados em formol a 10% tamponado, descalcificados e processados para inclusão em parafina. Os cortes histológicos foram corados mediante hematoxilina-eosina para análise histomorfométrica. Mediram-se a espessura cortical e a cavidade medular em cortes transversais de tíbia e fêmur e percentual de porosidade e densidade trabecular em cortes longitudinais de fêmur. RESULTADO E DISCUSSÃO: Não houve diferença estatística entre OVX e OVX + T nas diversas análises. Os resultados demonstram que a tibolona não melhorou de forma significativa a qualidade óssea, porém preservou a massa óssea cortical, nas diáfises femoral e tibial, e o osso trabecular, nos côndilos femorais. O uso prolongado de tibolona em concomitância com alta dose pode ter influenciado tais efeitos, já que estudos recentes têm preconizado a utilização de doses mais baixas na prevenção da osteoporose. CONCLUSÃO: A ooforectomia ocasionou perda óssea nas regiões analisadas; a tibolona, apesar de não ter aumentado a massa óssea, manteve-a em níveis satisfatórios

Influence of estrogen deficiency and tibolone therapy on trabecular and cortical bone evaluated by computed radiography system in rats Influência da deficiência estrogênica e do tratamento com tibolona no osso trabecular e cortical avaliada pelo sistema de radiografia computadorizada em ratas

PURPOSE: To verify the effects of tibolone administration on trabecular and cortical bone of ovariectomized female rats by computed radiography system (CRS). METHODS: The experiment was performed on two groups of rats previously ovariectomized, one received tibolone (OVX+T) while the other did not (OVX), those groups were compared to a control group (C) not ovariectomized. Tibolone administration (1mg/day) began thirty days after the ovariectomy and the treatment remained for five months. At last, the animals were euthanized and femurs and tibias collected. Computed radiographies of the bones were obtained and the digital images were used to determine the bone optical density and cortical thickness on every group. All results were statistically evaluated with significance set at P<0.05%. RESULTS: Tibolone administration was shown to be beneficial only in the densitometric analysis of the femoral head, performing higher optical density compared to OVX. No difference was found in cortical bone thickness. CONCLUSION: Ovariectomy caused bone loss in the analyzed regions and tibolone administered in high doses over a long period showed not to be fully beneficial, but preserved bone mass in the femoral head.<br>OBJETIVO: Verificar o efeito da administração de tibolona no tecido ósseo cortical e trabecular de ratas castradas através de radiografia computadorizada. MÉTODOS: O experimento foi realizado em dois grupos de ratas previamente ooforectomizadas, onde um grupo recebeu tibolona (OVX+T) e o outro não (OVX). Esses grupos foram comparados a um grupo controle (C) não ooforectomizado. A administração de tibolona (1mg/dia) começou trinta dias após a ooforectomia e o tratamento teve duração de cinco meses. No final, os animais foram mortos e fêmures e tibias coletados. As radiografias computadorizadas dos ossos foram obtidas e as imagens digitais usadas para determinar a densidade óssea e a espessura cortical em todos os grupos. Todos os resultados foram avaliados estatisticamente com significância estabelecida a 5%. RESULTADOS: A administração de tibolona mostrou ser benéfica apenas para análise densitométrica da cabeça do fêmur, apresentando maiores valores de densidade comparada ao grupo OVX. Nenhuma diferença significativa foi encontrada para espessura óssea cortical. CONCLUSÃO: A ooforectomia ocasionou perda óssea nas regiões analisadas e a tibolona administrada, em dose elevada e durante um longo período, mostrou não ser totalmente benéfica, porém preservou a massa óssea na cabeça femoral