Omentin is a recently identified adipocytokine, and we previously demonstrated that omentin played anti-inflammatory roles in vascular endothelial and smooth muscle cells. We also demonstrated that omentin induced vasodilation in rat isolated blood vessels. However, effects of omentin on blood pressure (BP) are not determined. Here, we examined whether intravenously injected omentin acutely alters BP of Wistar rats. Omentin (0.06-18 μg/kg) alone did not alter BP of Wistar rats. On the other hand, omentin (18 μg/kg) significantly inhibited noradrenaline (NA; 2 μg/kg)-induced increases in systolic BP and mean BP. Omentin (18 μg/kg) significantly inhibited angiotensin II (1 μg/kg)-induced increases in diastolic BP. Omentin (18 μg/kg) significantly inhibited dimorpholamine (3 mg/kg)-induced increases in diastolic BP. Omentin (18 μg/kg) failed to inhibit the NA (0.02-2 μg/kg)-induced increases of systolic BP in the nitric oxide (NO) synthase inhibitor, N(G)-nitro-l-arginine methyl ester (80 mg/kg, 1 day)-treated Wistar rats. In summary, we for the first time demonstrated that omentin inhibited agonists-induced increases in BP. The effect of omentin was suggested to be mediated likely via NO-dependent mechanism.
2010-12-01·Journal of Toxicological Sciences4区 · 医学
Measurement of respiratory function using whole-body plethysmography in unanesthetized and unrestrained nonhuman primates
Extended term, continuous measurement and observation of drug responses were performed to examine the feasibility of a custom-made whole-body plethysmograph for measuring respiratory function in unanesthetized, unrestrained monkeys. Using this apparatus, respiratory function (respiration rate, tidal volume, and minute volume) was observed for 23 hr in unanesthetized, unrestrained cynomolgus monkeys (Macaca fascicularis). The respiration rate, tidal volume, and minute volume in the light period (7:00 to 19:00) reached approximately 30% to 50% higher values than in the dark period (19:00 to 7:00), thus clearly exhibiting circadian variation in the cynomolgus monkey respiratory functions. Administration of morphine (10 mg/kg, s.c.) resulted in sustained reduction in tidal volume and minute volume, and ketamine (30 mg/kg [sub-anesthetic dose], i.m.) also produced sustained reduction in respiration rate, tidal volume, and minute volume. With dimorpholamine (1 mg/kg, i.v.) or caffeine (10 mg/kg, s.c.), respiration rate, tidal volume, and minute volume increased. Physiological saline (1 ml/kg, s.c. and 0.1 ml/kg, i.v.) and chlorpromazine (10 mg/kg, s.c.) produced no clear-cut changes in respiration rate, tidal volume, or minute volume. From the above results, we conclude that our custom-made whole-body plethysmograph is useful for measuring respiratory function in unanesthetized and unrestrained monkeys.
1984-10-01·Journal of pharmacological methods
A new method for measuring respiration in the conscious mouse.
作者: K Kigasawa ; K Saitoh ; A Tanizaki ; K Ohkubo ; O Iirino
A highly sensitive apparatus and method for measuring respiratory changes in conscious mice and rats is described. The apparatus is constructed from readily available components and consists of three sections: 1) mouse housing capsule and respiratory-sensitive part; 2) air supplying part; and 3) data recording part. Changes in the respiration of an encapsuled mouse can be accurately detected by means of changes in pressure exerted on the respiratory-sensitive part attached to the capsule. In our study, the rapid increases and decreases in the respiratory rates of these animals after the i.v. administration of respiratory depressing agents (morphine and arachidonate) and a respiratory stimulant (dimorpholamine) were recorded with exceptional accuracy by this procedure.