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Naphthylmedetomidine could replace medetomidine for inducing immobilization and sedation. A combination of naphthylmedetomidine-ketamine is suitable for relocating animals to other cages or for painless medical examinations.

Alpha-2 adrenoceptors (alpha(2)-ARs) are critically involved in regulating neurotransmitter release from sympathetic nerves and neurons and play an important role in the regulation of awareness, arousal and vigilance. In our recent study, dexmedetomidine, a full alpha(2)-AR agonist, produced antiaggressive effects in the social conflict test in mice at doses that were twice smaller than those producing sedation. The aim of this study was to ascertain antiaggressive effect of a novel drug naphthylmedetomidine, with a more selective alpha(2)-AR activity. Behavioral effects of naphthylmedetomidine (150-1200 microg/kg i.p.) were studied in the activity cage and in the social conflict tests in mice. Naphthylmedetomidine dose dependently decreased aggressive behavior during social conflict in aggressive mice with significant reduction already at the lowest doses tested (150 microg/kg), whereas locomotion and social investigation were significantly decreased only after four times bigger dose of naphthylmedetomidine (600 microg/kg) in aggressive mice. Naphthylmedetomidine had no effect on aggression in nonaggressive mice. Naphthylmedetomidine reduced locomotion in the activity cage significantly only at the highest doses tested (600 and 1200 microg/kg), and this effect was only partially reversed by administration of high doses of an alpha-2 antagonist atipamezole (3 and 10 mg/kg). In nonaggressive mice, the difference between the dose reducing dominant social behavior (social investigation) and locomotion (150 and 300 microg/kg, respectively) was smaller than in aggressive mice. In conclusion, naphthylmedetomidine showed a very strong and selective antiaggressive effect in aggressive mice, which was devoid of locomotion-inhibiting/sedative effect. This study suggests that naphthylmedetomidine may have clinical potential as antiaggressive drug.

Our results suggest that naphthylmedetomidine can be used to induce sedation in primates and other small animals while avoiding the serious side effects observed after administration of the currently used full alpha(2)-AR agonists.

Inhalational anesthetics have demonstrated cardioprotective effects against myocardial ischemia-reperfusion injury. Clinical studies in cardiac surgery have supported these findings, although not with the consistency demonstrated in experimental studies. Recent investigations have questioned the advantages of inhalational over intravenous anesthetics with respect to cardiac protection. Ketamine has been shown to be comparable with sufentanil, and has even demonstrated anti-inflammatory properties. Dexmedetomidine has been established as a sedative/anesthetic drug with analgesic properties, and has also demonstrated myocardial protective effects. In this retrospective observational study, the influence of ketamine-dexmedetomidinebased anesthesia (KET-DEX group; n=17) on the release of cardiac biomarkers was compared with that of sevofluranesufentanil-based anesthesia (SEVO group; n=21) in patients undergoing elective coronary artery bypass grafting. Compared with the SEVO group, the KET-DEX group exhibited significantly reduced cardiac troponin I (2.22±1.73 vs. 3.63±2.37 µg/l; P=0.02) and myocardial fraction of creatine kinase (CK-MB) levels (12.4±10.4 vs. 20.3±11.2 µg/l; P=0.01) on the morning of the first postoperative day. Furthermore, cardiac troponin I release, evaluated as the area under the curve, was significantly reduced in the KET-DEX group (32.1±20.1 vs. 50.6±23.2; P=0.01). These results demonstrate the cardioprotective effects of ketamine-dexmedetomidine anesthesia compared with those of sevoflurane-sufentanil anesthesia.

Oxytocin is a hormone therapeutically used mainly for its peripheral effects during pregnancy in the uterus and breasts. However, additional central effects, i.e. anxiolytic effect, decreased level of social stress and increased empathy have been also observed. Hence, the aim of our study was to evaluate if nasal oxytocin can be used as anxiolytic substance in rhesus monkeys (n=20) and rabbits (n=20). Simultaneously, mean arterial blood pressure, arterial oxygen saturation of hemoglobin and pulse rate were monitored in all the evaluated animals. While rabbits lost righting reflex, monkeys developed a dose-dependent loss of aggressiveness and/or anxiety as evaluated by behavioral methods (aggressive behavior was classified as non-sedated ‒ sedated ‒ strongly sedated).