“The definition of insanity is doing the same thing over and over again but expecting different results.” This quote by Albert Einstein highlights our need for new formats of communication to address the knowledge-action gap regarding climate change and other sustainability challenges. This includes reflection, and communication spaces, as well as methods and approaches that can catalyze the emergence of transformative change and action. In this article we present and reflect on experiments we carried out at international climate negotiations and conferences.
Arginine vasopressin (AVP) is regarded as facilitatory to adenohypophysial ACTH secretion at the level of the corticotropic cell. A central facilitatory action of AVP on hypothalamic corticotropin-releasing factor (CRF) has also been postulated, although conclusive evidence on this point is lacking. We directly tested this hypothesis and have found that intracerebroventricular administration of AVP attenuates secretion of immunoreactive CRF (irCRF) into the hypophysial portal circulation in urethane-anesthetized rats. This suppression occurred in a dose-dependent fashion. Conversely, immunoneutralization of AVP or treatment with an AVP antagonist increased portal concentrations of irCRF by 53% and 30%, respectively. These unexpected observations provide evidence for a tonic inhibitory role of central AVP in regulation of irCRF and thus ACTH secretion.
We report on the adsorption mechanism of pyrrole on the As-rich GaAs$(001)$-$c(4\ifmmode\times\else\texttimes\fi{}4)$ surface. We present measurements with reflectance anisotropy spectroscopy, x-ray photoelectron spectroscopy, and high-resolution scanning tunneling microscopy and spectroscopy (STS) and our experiments show that the surface defects play a crucial role for the adsorption configuration. We found that pyrrole physisorbs on the ideal $c(4\ifmmode\times\else\texttimes\fi{}4)$ surface and does not form any covalent bonds to the surface atoms. At submonolayer coverage, however, we found evidence for single molecules that are chemisorbed at surface defects. We could identify the molecular electronic states with single molecule STS and could distinguish the chemisorbed and physisorbed molecular species in the STS spectra.
Recently, it has been reported that oxytocin (OT), classically known for its function during parturition and lactation, is secreted in response to stressful stimuli in male rats. In these and in the present report it was found that swimming stress, restraint stress, ether stress, and footshock stress elevate OT secretion without affecting arginine-vasopressin (AVP) secretion. In the present studies, we investigated the possible modulation of OT secretion by CRF which is known to be released during stress. Male and female rats received intraventricular (icv) injections of 0.75 nmol (5 μg) rat CRF and were killed 5 min after the treatment. CRF significantly elevated OT secretion in male and female rats 3.4- and 4-fold, respectively. Plasma AVP levels were not affected by the treatment. The effect of CRF on OT release was structure specific since rat CRF, ovine CRF, and sauvagine were equipotent releasers of OT while an inactive analog to CRF, ovine CRF7–41 did not change plasma OT levels. In another set of experiments rats were pretreated with either CRF-antiserum (0.5 ml iv) or dexamethasone (20 μg/rat ip) a nd then injected with icv CRF. Both CRF-antiserum and dexamethasone blocked the rise in ACTH release after icv CRF completely but did not influence the OT response. This suggests CRF may be acting centrally but not at the level of the neurohypophysis to change OT secretion. Since parvocellular but not magnocellular neurons of the paraventricular nucleus have been demonstrated to be steroid sensitive in immunohistochemical studies, we suggest CRF may act directly or indirectly upon magnocellular neurons to increase OT release. Intravenous administration of 0.75 nmol CRF increased both OT and AVP levels in peripheral blood. The magnitude of this increase was similar (2- to 4-fold stimulation) to responses after icv administration of CRF. Intravenous administration of CRF results in hypotension and may therefore cause a baroreceptor mediated release of AVP and OT. From the above evidence we conclude: 1) physical and mental stresses which do not result in changes in blood volume or osmolality evoke an increase in OT secretion while AVP secretion remains unchanged; 2) CRF administered icv mimics OT responses observed after ether stress or footshock stress; 3) CRF may play a role in regulating stress-induced OT secretion in the rat. (Endocrinology119: 1558–1563, 1986)
