Mice lacking brain-type creatine kinase activity show defective thermoregulation.

Contains fulltext : 79580.pdf (publisher's version ) (Closed access)The cytosolic brain-type creatine kinase and mitochondrial ubiquitous creatine kinase (CK-B and UbCKmit) are expressed during the prepubescent and adult period of mammalian life. These creatine kinase (CK) isoforms are present in neural cell types throughout the central and peripheral nervous system and in smooth muscle containing tissues, where they have an important role in cellular energy homeostasis. Here, we report on the coupling of CK activity to body temperature rhythm and adaptive thermoregulation in mice. With both brain-type CK isoforms being absent, the body temperature reproducibly drops ~1.0 degrees C below normal during every morning (inactive) period in the daily cycle. Facultative non-shivering thermogenesis is also impaired, since CK--/-- mice develop severe hypothermia during 24 h cold exposure. A relationship with fat metabolism was suggested because comparison of CK--/-- mice with wildtype controls revealed decreased weight gain associated with less white and brown fat accumulation and smaller brown adipocytes. Also, circulating levels of glucose, triglycerides and leptin are reduced. Extensive physiological testing and uncoupling protein1 analysis showed, however, that the thermogenic problems are not due to abnormal responsiveness of brown adipocytes, since noradrenaline infusion produced a normal increase of body temperature. Moreover, we demonstrate that the cyclic drop in morning temperature is also not related to altered rhythmicity with reduced locomotion, diminished food intake or increased torpor sensitivity. Although several integral functions appear altered when CK is absent in the brain, combined findings point into the direction of inefficient neuronal transmission as the dominant factor in the thermoregulatory defect

Variabilidade e comportamento de cultivares de coqueiro anão nos tabuleiros costeiros do norte de Sergipe Variability and behavior to cultivars of dwarf coconut in the costal boards of the North of Sergipe

O objetivo do trabalho foi avaliar a variabilidade de cultivares de coqueiro anão para caracteres morfológicos nos tabuleiros costeiros do Norte de Sergipe. O delineamento experimental utilizado foi em blocos casualizados, com seis cultivares de coqueiro anão, quatro blocos, sendo 16 plantas úteis/parcela. O experimento foi desenvolvido desde 1997, na Fazenda Agreste em Neópolis (SE). As cultivares Anão vermelho do Brasil de Gramame (AVBrG), da Malásia (AVM) e de Camarões (AVC), Anão amarelo do Brasil de Gramame (AABrG) e da Malásia (AAM) e o Anão Verde do Brasil de Jiqui (AVeBrJ). Para cada característica avaliada trimestralmente de 2001 a 2004, foi realizada análise de variância e estimados os componentes de variação fenotípica, genética e ambiental. Existe variabilidade entre os anões para as características: número de folhas vivas (NFV) e emitidas (NFE), circunferência do estipe (CircE), comprimento do estipe (CE), número de inflorescências emitidas (NIE) e número de flores femininas por inflorescência (NFFI). O AVC e o AVeBrJ apresentaram menores CE que os demais, característica importante por redução do porte do coqueiro. O anão amarelo da malásia (AAM) foi superior aos AVeBrJ, AVM e AVC quanto ao NFE. O AVM foi superior aos AAM, AABrG, AVeBrJ e AVC quanto à CircE. O AVC apresentou comportamento inferior aos demais para NFV, NFE, CircE e NIE, sendo semelhante a eles para NFFI. O AVeBrJ foi superior ao AAM, AVBrG e AVM quanto à NFFI.<br>The objective of this work was to evaluate the variability of dwarf coconut palm cultivars for morphologic characters in the Coastal Boards of the North of Sergipe State. The experimental design was randomized block, with six cultivars, four blocks and 16 usefull plants/plot. The experiment was driven since 1997, in the Agreste farm in Neópolis (SE). The cultivars dwarf coconut palm red dwarf of Brazil Gramame (AVBrG), of Malaysia (AVM) and Cameroon (AVC), yellow dwarf of Brazil de Gramame (AABrG) and of Malaysia (AAM) and the green dwarf of Brazil de Jiqui (AVeBrJ). For each characteristic, quarterly evaluations from 2001 the 2004, were analyses of variance and estimate of the components of variation phenotypical, genotipycal and environmental. There is variability among the dwarves for the characteristics: alive leaf number (NFV), emitted leaf number (NFE), leaf number dead (NFM), circumference of stem (CircE), length of stem (CE), number of emitted inflorescence (NIE) and number of feminine flowers for inflorescence (NFFI). The AVC and the AVeBrJ presented smaller CE that the other dwarves, important characteristic for reduction of the load of the coconut palm. The AAM was superior to the AAM, AABrG, AVeBrJ and AVC for the CircE, while. The AVC presented inferior behavior in relation to the others for NFV, NFE, CircE and NIE being similar to them for NFFI. The AVeBrJ was superior to the AAM, AVBrG and AVM in relation to NFFI