The influence of a new derivate of kisspeptin-10 - Kissorphin (KSO) on the rewarding effects of morphine in the conditioned place preference (CPP) test in male rats.

Kissorphin (KSO) is a new peptide derived from kisspeptin-10. Previous study has indicated that this peptide displays neuropeptide FF (NPFF)-like anti-opioid activity. Herein, we examined the influence of KSO (1; 3, and 10 nmol, intravenously [i.v.]), on the rewarding action of morphine (5 mg/kg, intraperitoneally [i.p.]), using the unbiased design of the conditioned place preference (CPP) paradigm in rats. To test the effect of KSO on the acquisition of morphine-induced CPP, KSO and morphine were co-injected during conditioning with no drugs treatment on the test day. To investigate the effect of KSO on the expression of morphine-induced CPP, morphine alone was given during the conditioning phase (1 × 3 days) and KSO was administered 5 min prior to the placement in the CPP apparatus on the test day. To estimate the influence of KSO on the reinstatement of morphine-induced CPP, KSO was given 5 min before a priming dose of morphine (5 mg/kg, i.p.) on the reinstatement test day. The results show that KSO inhibited the acquisition, expression and reinstatement of morphine-induced CPP. The strongest effect of KSO was observed at the dose of 10 nmol (acquisition and reinstatement) or 1 nmol (expression). KSO given alone, neither induced place preference, nor aversion. Furthermore, the morphine-modulating effects of KSO were markedly antagonized by pretreatment with RF9 (10 nmol, i.v.), the NPFF receptors selective antagonist. Thus, KSO inhibited the morphine-induced CPP mainly by involving specific activation of NPFF receptors. Overall, these data further support the anti-opioid character of KSO.

The Role of Inspiratory Muscle Training in the Process of Rehabilitation of Patients with Chronic Obstructive Pulmonary Disease.

Chronic obstructive pulmonary disease (COPD) adversely affects the quality of life and life expectancy of patients. Shortness of breath, cough, and fatigue in lower limbs are the main reasons limiting physical activities of patients. The lack of physical activity results in poorer muscle strength. The latest guidelines regarding breathing rehabilitation in COPD patients emphasize a significant role of inspiratory muscle exercises. The objective of the present study was to evaluate the effects of an 8-week long inspiratory muscle training, interval training on a cycle ergometer, and training combining both kinds of rehabilitation, on pulmonary function, health-related quality of life, and the tolerance to exercise in patients with COPD. The study was conducted in a group of 43 patients with diagnosed COPD stage II and III according to GOLD. They were randomly divided into four training groups: inspiratory muscle training (Group 1), cycle ergometer training (Group 2), cycle ergometer and inspiratory muscle training (Group 3), control group - patients who did not participate in any rehabilitation programs (Group 4 - control). Before the rehabilitation process and after its completion the patients were medically examined, they completed a health-related quality of life questionnaire, performed a 6-min walk test, spirometry, and a treadmill exercise test according to the modified Bruce protocol. The results demonstrate a significant improvement in the quality of life measured for Group 3 in comparison with the control group.