Given a passage with a context and an answer, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

[EX Q]: Context: Cyclosporine causes intrarenal vasoconstriction, which may account for its nephrotoxic side effects. Plasma levels of the vasoconstrictor peptide endothelin-1 are increased after cyclosporine administration, and endothelin-1 has been shown to cause renal vasoconstriction. In this study we used in vivo microscopy to investigate the role of endothelin-1 in cyclosporine-induced vasoconstriction.', 'Hydronephrotic kidneys in decerebrate rats were suspended in an environmentally controlled tissue bath with neurovascular supply intact. Interlobular, afferent, and efferent arteriolar diameters and flow were measured by videomicroscopy and Doppler velocimetry. Cyclosporine was added to the tissue bath, and measurements were repeated for 60 minutes. In study groups endogenous endothelin-1 was blocked by infusion of either specific endothelin antiserum or an endothelin-1 receptor antagonist.', 'Cyclosporine caused constriction of the interlobular artery by 20% +/- 2% and a corresponding decrease in blood flow by 66% +/- 4%. The afferent and efferent arterioles constricted to a similar degree. This vasoconstriction was entirely prevented by infusion of either the endothelin antiserum or the receptor antagonist. The antagonist reagents alone had no effect on hemodynamic parameters or renal microvessel diameters.
Answer: The acute renal vasoconstriction induced by cyclosporine is mediated by endothelin-1. Endogenous endothelin-1 has little role in maintaining basal vascular tone.
[EX A]: Is acute cyclosporine-induced renal vasoconstriction mediated by endothelin-1?

[EX Q]: Context: The checkpoint kinase 1 (Chk1) functions not only in genotoxic stresses but also in normal cell cycle progression, particularly in the initiation, progression and fidelity of unperturbed mitosis. In this study, we investigated the role of Chk1 in regulating the metaphase-anaphase transition in mammalian cells.', 'The mitotic progression was monitored by flow cytometry analysis. The levels of cyclin B1, Cdc20 and Mad2 were measured by Western blotting. Metaphase chromosome alignment and the subcellular localization of Cdc20 and Mad2 were analyzed by immunofluorescence and confocal microscopy.', 'Cyclin B1 degradation and the metaphase-anaphase transition were severely blocked by Chk1 siRNA. Depletion of Chk1 induced chromosome alignment defect in metaphase cells. The kinetochore localization of Cdc20, Mad2 was disrupted in Chk1 depleted cells. Chk1 abrogation also dramatically reduced the protein expression levels of Cdc20 and Mad2.
Answer: These results strongly suggest that Chk1 is required for the metaphase-anaphase transition via regulating the subcellular localization and the expression of Cdc20 and Mad2.
[EX A]: Is chk1 required for the metaphase-anaphase transition via regulating the expression and localization of Cdc20 and Mad2?

[EX Q]: Context: The purpose of the present study was to investigate the effect of supplementation with chicken breast extract (CBEX), which was a rich source of carnosine and anserine, on acid-base balance and performance during intense intermittent exercise.', 'Eight male subjects performed intense intermittent exercise that consisted of 10 x 5-s maximal cycle ergometer sprints with a 25-s recovery period between each sprint. The subjects ingested 190 g of the test soup containing either CBEX or a placebo 30 min before the commencement of exercise. Arterial blood samples were collected at rest and during exercise to estimate the carnosine and anserine concentrations, pH, and bicarbonate concentration ([HCO3-]).', 'Concentrations of anserine and its related amino acid significantly increased 30 min after CBEX supplementation, as compared with their values at rest. However, carnosine did not increase significantly. Following CBEX supplementation, the pH was significantly higher (P < 0.05) at the end of exercise, and [HCO3-] was also significantly higher (P < 0.05) during the latter half of exercise and after exercise. There were no significant differences in the total power and mean power of each set between the CBEX and placebo supplemented groups.
Answer: Although oral supplementation with CBEX (which is a rich source of carnosine and anserine) increased the contribution of the nonbicarbonate buffering action and decreased bicarbonate buffering action in blood, intense intermittent exercise performance did not improve significantly.
[EX A]:
Does carnosine and anserine ingestion enhance contribution of nonbicarbonate buffering?