Hageman factor activation and tight junction disruption in mice challenged with attenuated endotoxin.

Endotoxin treated with chromium chloride is less toxic to mice than the parent molecule, but can disrupt intestinal permeability barriers and has an enhanced ability to activate Hageman factor.     

Hibernation at moderate temperatures: a continuation of slow wave sleep

Summary Golden-mantled ground squirrels (Citellus lateralis) displayed virtually continuous electrophysiological states of sleep when hibernating at moderate ambient temperatures (22°C). Rapid-eye-movement sleep progressively diminished with the fall in body temperature so that at a body temperature of 23°C it was completely absent. At this temperature hibernation was characterized by slow wave sleep isomorphic with slow wave sleep episodes at non-hibernating (euthermic) body temperatures.Supported by National Institute of Health grants GM 23694 awarded to R.J. Berger and GM 23695 awarded to H.C. Heller.     

The action of substance P on mesencephalic reticular and substantia nigral neurones of the rat.

Extracellular recordings were made from neurones in the mesencephalic reticular formation and substantianigra of the rat which was anaesthetized with urethane 1.5-2 g/kg i.p. Out of 44 cells tested 42 were excited by Substance P applied iontophoretically and in some cases this excitation was rapid. Evidence is presented for Substance P as a putative excitatory transmitter onto reticular and nigral neurones possibly released from primary sensory afferents.     

The involvement of serotonin in induced ovulation in the immature rat.

In pregnant mare's serum gonadotropin (PMS) treated immature rats the cortex, cerebellum, caudate nucleus and hypothalamus were isolated and analyzed for their serotonin (5-HT) content at 6-h intervals for 72 h. Results showed a general trend of significant variation occurring in days 1 and 3 after PMS injection with no major variations observed on the second day. The results obtained suggest a possible involvement of 5-HT in the control of ovulation.     

Juvenile hormone: Evidence for a role in the feeding rhythm ofOncopeltus fasciatus (Dallas)

Summary The diurnal feeding rhythm of female milkweed bugs was damped when fed nonhost seeds. Juvenoid treatment partially restored the normal rhythm. Precocene II-treated milkweed seed-fed females fed arrhythmicly during the light phase without reduced total feeding activity. This effect was largely prevented by simultaneous treatment with JH III.I thank Dr Judith H. Willis, Univ. of Illinois, for providing facilities, Meyer Schwartz of ARS, USDA, Beltsville, MD, USA, for providing the precocene II, and Dr W. S. Bowers, formerly of ARS, USDA, Beltsville, MD, for supplying the juvenoid. This work was supported in part by grant AG-00248 from the National Institutes of Health to J. H. Willis.