English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

There is evidence that the potent vasoconstrictor angiotensin II (Ang II) regulates luteal functions. In the present study, the effect of an intraluteal injection of Ang II alone or in combination with pretreatment with a subluteolytic i.m. dose of PGF(2alpha) on the concentration of plasma progesterone, corpus luteum regression and duration of the oestrous cycle was investigated. Cows were assigned randomly to receive an intraluteal injection of either: (i) 500 microl saline 30 min after i.m. administration of saline (control, n = 7); (ii) 500 microl saline 30 min after i.m. administration of a subluteolytic dose (125 microg) of a PGF(2alpha) analogue (1/4 PGF(2alpha), n = 5); (iii) 2 mg Ang II in 500 microl saline 30 min after i.m. administration of saline (Ang II, n = 5); or (iv) 2 mg Ang II in 500 microl saline 30 min after i.m. administration of a subluteolytic dose (125 microg) of the PGF(2alpha) analogue (1/4 PGF(2alpha)/Ang II, n = 6) on day 12 of the oestrous cycle. There were no significant changes in plasma progesterone concentrations in the control, 1/4 PGF(2alpha) or Ang II treatment groups. Treatment with 1/4 PGF(2alpha)/Ang II decreased plasma progesterone concentration, and induced luteolysis and oestrus. The onset of oestrus in cows treated with full-dose (500 microg) PGF(2alpha) (3.1 +/- 0.2 (mean +/- SEM) days after treatment) was significantly earlier than that in cows treated with 1/4 PGF(2alpha)/Ang II (4.8 +/- 0.2 days after treatment) (P &lt; 0.05). The results from the present study demonstrate that an intraluteal injection of Ang II after i.m. administration of a subluteolytic dose of PGF(2alpha) analogue induces luteolysis and oestrus. Thus, these results support the contention that Ang II is directly correlated with the process of luteal regression in cows.

The cooperative action of angiotensin II with subluteolytic administration of PGF2alpha in inducing luteolysis and oestrus in the cow