Studies were undertaken to characterize angiotensin peptides in hypophysial-portal blood of conscious sheep and to determine whether the median eminence (ME) secretes angiotensin peptides into the hypophysial-portal circulation. Simultaneous measurements of angiotensin peptides in jugular and hypophysial-portal plasma were performed in 6 sheep. Cerebrospinal fluid (CSF) was collected and data for hypophysial-portal plasma were corrected for CSF contamination. Angiotensin peptides were also measured in extracts of sheep ME. In a separate group of 4 sheep, simultaneous measurements of angiotensin peptides in arterial and jugular plasma were performed. Using high performance liquid chromatography-based radioimmunoassays, 8 angiotensin peptides were measured: Ang-(1–7), Ang II, Ang-(1–9), Ang I, Ang-(2–7), Ang III, Ang-(2–9), and Ang-(2-10). Renin, angiotensinogen and prolyl endopeptidase were also measured. No differences in angiotensin peptide levels in arterial and jugular plasma were observed. Angiotensin peptide levels in hypophysial-portal plasma were similar to those in jugular plasma, except for Ang-(1–7), the levels of which were 5-fold higher in hypophysial-portal plasma, and Ang I, for which the levels in hypophysial-portal plasma were 46% of the jugular levels. Renin and angiotensinogen levels were similar in arterial, jugular, and hypophysial-portal plasma. Angiotensin peptide contents of sheep ME were < 16 fmol/ME. However, the prolyl endopeptidase content of sheep ME was 430-fold higher than plasma levels. The low levels of angiotensin peptides in sheep ME indicate that it does not secrete these peptides into the hypophysial-portal circulation. Rather, the high level of prolyl endopeptidase in ME is consistent with region-specific metabolism of Ang I delivered to the ME by arterial blood, generating increased levels of Ang-(1–7) in hypophysial portal plasma. The increased levels of Ang-(1–7) in hypophysial-portal plasma may play a role in regulation of pituitary function.

No abstract

No abstract

No abstract

Much of the debate around a potential British exit (Brexit) from the European Union has centred on the potential macroeconomic impact. In this paper, we instead focus on understanding market expectations for price action around the Brexit referendum date. Extracting implied distributions from the GBPUSD option volatility surface, we originally estimated, based on our visual observation of implied probability densities available up to 13 June 2016, that the market expected that a vote to leave could result in a move in the GBPUSD exchange rate from 1.4390 (spot reference on 10 June 2016) down to a range in 1.10 to 1.30, i.e., a 10-25% decline-very probably with highly volatile price action. To quantify this more objectively, we construct a mixture model corresponding to two scenarios for the GBPUSD exchange rate after the referendum vote, one scenario for "remain" and one for "leave". Calibrating this model to four months of market data, from 24 February to 22 June 2016, we find that a "leave" vote was associated with a predicted devaluation of the British pound to approximately 1.37 USD per GBP, a 4.5% devaluation, and quite consistent with the observed post-referendum exchange rate move down from 1.4877 to 1.3622. We contrast the behaviour of the GBPUSD option market in the run-up to the Brexit vote with that during the 2014 Scottish Independence referendum, finding the potential impact of Brexit to be considerably higher.

No abstract

No abstract

No abstract