58 research outputs found
Fluoreszenzmikroskopische Beobachtung des Wachstums von Pollenschläuchen im Griffel- und Fruchtknotengewebe
Untersuchung über die Einflüsse verschiedener Umweltfaktoren auf die Funktionsfähigkeit der Pollen von Tomaten (Lycopersicon Esculentum Mill.), insbesondere solcher mit erblicher Neigung zur Parthenokarpie
Methods for Selection of Low-Temperature Tolerant Mutants of Chrysanthemum morifolium Ramat. Using Irradiated Cell Suspension Cultures III. Comparison of Mutants Selected with or without Preselection in vitro at Low-Temperature
Methods for selection of low-temperature tolerant mutants of Chrysanthemum morifolium Ramat using irradiated cell suspension cultures 3. Comparison of mutants selected with or without preselection in vitro at low-temperature.
Methods for selection of low-temperature tolerant mutants of Chrysanthemum morifolium Ramat using irradiated cell suspension cultures 2. Preselection in vitro under low-temperature stress.
Methods for the selection of low-temperature tolerant mutants of Chrysanthemum morifolium Ramat. by using irradiated cell suspension cultures.
Chilling Tolerance, Cold Hardening and Freezing Tolerance of Low-temperature-tolerant Mutants of Dendranthema x grandiflorum (Ramat.) Kitamura
Methods for the Selection of Low-Temperature Tolerant Mutants of Chrysanthemum morifolium Ramat. by Using Irradiated Cell Suspension Cultures. I. Selection of Regenerants in vivo under Suboptimal Temperature Conditions
Selective activation of the hypothalamic vasopressinergic system in mice deficient for the corticotropin-releasing hormone receptor 1 is dependent on glucocorticoids.
Deficiency of CRH receptor 1 (CRHR1) severely impairs the stress response of the hypothalamic-pituitary-adrenocortical (HPA) system and reduces anxiety-related behavior in mice. Intriguingly, in mice deficient for the CRHR1 (Crhr1-/-), basal plasma levels of ACTH are normal, suggesting the presence of compensatory mechanisms for pituitary ACTH secretion. We therefore studied the impact of the hypothalamic neuropeptides arginine vasopressin (AVP) and oxytocin (OXT) on HPA system regulation in homozygous and heterozygous Crhr1 mutants under basal and different stress conditions. Basal plasma AVP concentrations were significantly elevated in Crhr1-/- mice. AVP messenger RNA expression was increased in the paraventricular nucleus of Crhr1-/- mutants together with a marked increase in AVP-like immunoreactivity in the median eminence. Administration of an AVP V1-receptor antagonist significantly decreased basal plasma ACTH levels in mutant mice. After continuous treatment with corticosterone, plasma AVP levels in homozygous Crhr1-/- mice were indistinguishable from those in wild-type littermates, thus providing evidence that glucocorticoid deficiency is the major driving force behind compensatory activation of the vasopressinergic system in Crhr1-/- mice. Neither plasma OXT levels under several different conditions nor OXT messenger RNA expression in the paraventricular nucleus were different between the genotypes. Taken together, our data reveal a selective compensatory activation of the hypothalamic vasopressinergic, but not the oxytocinergic system, to maintain basal ACTH secretion and HPA system activity in Crhr1-/- mutants
Expression of CRHR 1 and CRHR 2 in mouse pituitary and adrenal gland: implications for HPA system regulation.
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