Endocrine Abstracts

In late pregnancy, the hypothalamo-pituitary-adrenal (HPA) axis is less responsive to immune challenge(1). Circulating and brain levels of allopregnanolone (AP), a neuroactive steroid and allosteric enhancer at inhibitory GABAA receptors, increase during pregnancy(2) and AP treatment attenuates stress-induced HPA activity in male rats(3). Here we sought a role for AP in attenuated HPA axis responses to interleukin-1-beta (IL-1B) in pregnant rats. Conscious pregnant (day 21) an...

Orexins are hypothalamic peptides known to stimulate food intake. Recently, orexins have been shown to activate the HPA axis at a central level1. We have previously shown that during late pregnancy the responsiveness of the HPA axis to a range of stressors is attenuated and suggested that the corticotropin releasing hormone (CRH) neurones or pathways impinging on them are less responsive2. If the CRH neurones themselves are less responsive, they should al...

NPY acts centrally to stimulate appetite and the HPA axis. During late pregnancy enhanced inhibition of parvocellular paraventricular nucleus (pPVN) corticotrophin releasing hormone (CRH)/ arginine vasopressin (AVP) neurones reduces HPA-axis stress responses1,2. We investigated activation of hypothalamic neurones regulating HPA responses to NPY, and a role for endogenous opioids in HPA hyporesponsiveness in late pregnancy.Pregnant (d21) and vi...