Vasopressin pressor receptor-mediated activation of HPA axis by acute ethanol stress in rats.

The plasma arginine vasopressin (AVP), ACTH, and corticosterone levels and the hypothalamic corticotropin-releasing hormone (CRH) content were measured after oral administration of 1 ml of 75% ethanol to rats, a model known to induce acute gastric erosions and stress. Elevated plasma AVP, ACTH, and corticosterone levels were detected 1 h after ethanol administration. Treatment with the vasopressin pressor (V(1)) receptor antagonist [d(CH(2))(5)Tyr(Me)-AVP] before ethanol administration significantly reduced the ACTH and corticosterone level increases. A higher hypothalamic CRH content was measured at 30 or 60 min after ethanol administration. V(1) receptor antagonist injection, 5 min before ethanol administration, inhibited the rise in hypothalamic CRH content. The protein synthesis blocker cycloheximide prevented the hypothalamic CRH content elevation after stress. The AVP-, CRH-, and AVP + CRH-induced in vitro ACTH release in normal anterior pituitary tissue cultures was also prevented by pretreatment with the V(1) receptor antagonist. The results support the hypothesis that stress-induced AVP may not only act directly on the ACTH producing anterior pituitary cells but also indirectly at the hypothalamic level via the synthesis and release of CRH.

Isihlambezo: utilization patterns and potential health effects of pregnancy-related traditional herbal medicine.

Isihlambezo is a herbal decoction used by many Zulu women in South Africa as a preventative health tonic during pregnancy. Though the practice is cited by ethnographers and medical practitioners, few studies have focused on specific elements of isihlambezo use and preparation. Moreover, though some evidence exists suggesting negative effects of its ingestion, the maternal-fetal health impact and toxicity of isihlambezo have not been adequately studied. We examined two aspects of this traditional antenatal health practice: (1) the potential impact of urbanization and access to Western clinic-based care on popularity and utilization patterns of isihlambezo, and (2) the potential maternal-fetal health effects of its use. Interviews were conducted among rural and urban women in clinic and non-clinic settings regarding socio-behavioral aspects of isihlambezo use. The pharmacology of certain plant ingredients of isihlambezo was investigated through laboratory assays, literature review, and interviews with traditional healers. There were significant differences by area of interview in nearly all aspects of isihlambezo use examined. Though isihlambezo was most popular among urbanites and clinic non-attenders, it was considered an important antenatal health care alternative by the majority of women surveyed. Mixing traditional and clinic-based antenatal care was also strongly advocated. Pharmacological analysis suggested the possibility of both therapeutic and harmful consequences of isihlambezo. It was suggested that the following factors might contribute the popularity of isihlambezo among urban women: high cost and inferior quality of clinic care, use of isihlambezo as a means of adapting to urbanization-related stress, and socio-cultural transition.