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.

[Q]: Context: Kisspeptin and naloxone stimulate the reproductive axis while morphine inhibits its function. We have investigated the effect of central injection of kisspeptin-10 on mean plasma testosterone concentration in morphine or naloxone pretreated rats.', 'In this experimental study, 60 male Wistar rats that were divid- ed into 12 groups (n=5 per group) received saline, kisspeptin (1 nmol, ICV), naloxone (2 mg/kg, subcutaneously), morphine (5 or 10 mg/kg, sc) or co-administrations of kisspeptin, morphine and naloxone at 09:00 - 09:30. In the co-administrated groups, kisspeptin was injected 15 minutes following morphine or naloxone injections. Blood samples were collected 60 minutes following injections via the tail vein. Plasma testosterone concentration was measured by a rat testosterone ELISA kit.', 'Central injection of kisspeptin or subcutaneous injection of naloxone significantly increased the mean plasma testosterone concentration compared to saline while subcutaneous injections of different doses of morphine (5 or 10 mg/kg) significantly decreased testosterone compared to saline. The results revealed that morphine significantly attenuated the testosterone increase after kisspeptin injection compared to kisspeptin while a stimulatory additive effect was observed in the kisspeptin/naloxone group compared to either naloxone or kisspeptin.
Answer: Morphine and kisspeptin systems may interact with each other to control the hypothalamic-pituitary-gonadal (HPG) axis.
[A]: Does morphine attenuate testosterone response to central injection of kisspeptin in male rats?


[Q]: Context: Nonasthmatic eosinophilic bronchitis (EB) has emerged as a useful tool to study the structural and inflammatory mechanisms of airway hyperresponsiveness (AHR) in asthma. We have previously shown that vascular remodeling and reticular basement membrane (RBM) thickening are present in EB. However, it is not known whether other features of structural remodeling including increased airway smooth muscle (ASM) mass, matrix deposition, and glandular hyperplasia are also present in EB.', 'We sought to determine whether structural remodeling occurs in EB and is associated with AHR and airflow limitation.', 'Forty-two patients with asthma, 21 patients with EB, and 19 healthy volunteers were recruited. ASM area, RBM thickness, collagen 3 deposition, glandular area, mast cells, and granulocytes were assessed in bronchial biopsy samples.', 'Nonasthmatic eosinophilic bronchitis and asthma were associated with a significant increase in ASM mass and RBM thickness compared with healthy subjects. In contrast, we did not observe any significant differences in collagen 3 deposition in the lamina propria and ASM or the % area of glands in the lamina propria. Univariate analysis demonstrated that mast cell numbers in the ASM were the only feature of remodeling associated with AHR (beta = -0.51; P = .004). Stepwise linear regression revealed that a combination of mast cell numbers in the ASM (beta = -0.43) and disease duration (beta = -0.25; model-adjusted R(2) = 0.26; P = .027) best modeled AHR.
Answer: Mast cell localization to the ASM bundle, but not structural remodeling of the airway wall, is associated with AHR in asthma.
[A]: Is airway hyperresponsiveness dissociated from airway wall structural remodeling?


[Q]: Context: Clonidine prolongs the duration of sensory and motor block induced by bupivacaine, and this association, in constant infusion by the epidural route, is used for postoperative analgesia. After a near-fatal intravenous bolus of bupivacaine in dogs, clonidine improves ventricular electrophysiologic parameters, but probably worsens bupivacaine-induced bradycardia and depression of the myocardial contractility. The current study, using a rodent animal model, evaluated the influence of clonidine pretreatment on the systemic toxic effects of bupivacaine overdose induced by a constant intravenous infusion.', 'Twenty Wistar male rats were anesthetized with thiopental, and controlled ventilation was started with an equal mixture of O2 and N2O. Electrocardiogram (ECG), electroencephalogram (EEG), and invasive arterial blood pressure were continuously recorded. Clonidine (5 micrograms/kg) or saline was injected intravenously in a randomized fashion. After 15 min, an intravenous infusion of bupivacaine was started at 2 mg.kg-1 x min-1. The time of occurrence of the bupivacaine-induced toxic events was recorded and the doses were calculated. Ten (five in each group) additional rats, pretreated according to the same protocol, were killed at the time of the first dysrhythmia, for blood sampling and plasma bupivacaine concentration measurement.', 'Clonidine reduced heart rate and arterial blood pressure before bupivacaine infusion (P < 0.05). The threshold doses at the first QRS modification (11.3 +/- 5.6 vs. 2.1 +/- 0.9 mg/kg) and the first dysrhythmia (40.6 +/- 15.3 vs. 8.48 +/- 3.7 mg/kg), the increase in EEG total spectral power (33.3 +/- 21.9 vs. 8.2 +/- 5.1 mg/kg), the 25 and 50% reduction in baseline mean arterial pressure and heart rate, the isoelectric EEG (58.6 +/- 14 vs. 22 +/- 6.6 mg/kg), and the final systole (99 +/- 16 vs. 51.8 +/- 14.5 mg/kg) were significantly greater in the clonidine group than in the saline group (P < 0.01). The time between the first dysrhythmia and 50% reduction of baseline mean arterial blood pressure was not different between the groups. In the additional series, the first dysrhythmia occurred later (10.9 +/- 4.5 vs. 3.2 +/- 1.0 min, P < 0.01) and plasma bupivacaine levels were greater (18.7 +/- 8.0 vs. 7.8 +/- 3.2 micrograms/ml, P < 0.01) in the clonidine group than in the saline group.
Answer: In this model, clonidine given prophylactically delays the toxic manifestations of bupivacaine overdose and does not accentuate the subsequent hypotension.
[A]:
Does clonidine pretreatment reduce the systemic toxicity of intravenous bupivacaine in rats?