Detailed Instructions: Given a passage with a question and an answer to that question, classify if the answer actually answers the question into 'yes' or 'no'. Output 'yes' if the answer answers the question and output 'no' if the answer does not answer the question.
Q: Question: Is aortic vasoconstriction related to smooth muscle cells ET-A and ET-B receptors involved in hypoxia-induced sustained systemic arterial hypertension in rats?
Answer: This work clearly suggests that, following long term exposure to hypoxia, ET-1 and ET-1 receptors are not involved in the persistence of systemic hypertension in a rat model, and that chronic exposure to severe hypoxic stress was associated with a downregulation of the ET-A receptors response to ET-1.
A:
no