Vocative Intestinal PolyPEPTIDE (VIP), has been found in different neurotransmitter systems and exists in various nerve tracts in the brain. Potential role of this PEPTIDE in physiological processes such as regulation of sleep and wakefulness, and biological rhythms has been confirmed in several reports. In the present research effects of intracerebroventricular (ICV) injection of a VIP antagonist, 4-CID- Phe6/leu 17, at different circadian time on rest-activity cycle of rats during free- run, has been investigated. Results of this study showed that brain clock in definite time of its endogenous rhythmic activity is sensitive to the antagonist and presents this sensitivity through phase advance following ICV injection at CT 6. While injection of same drug at other circadian time and also injection of artificial cerebrospinal fluid has no effect on this rhythm. According to our experiment and considering the results of others, the sensitivity of locomotor, rhythms to VIP ergic system is revealed. In previous studies, effect of this antagonist on sleep homeostasis has also been demonstrated. Regarding difference in type and distribution of known VIP receptors in sleep homeostasis and biological rhythm of locomotor, activity, it is clear that above mentioned synthetic antagonist has no speciftcity for known VIP receptors.

Background: VASOACTIVE intestinal PEPTIDE (VIP) plays an important role in modulating coronary blood flow and heart rate. The purpose of the present study was to investigate the effect of eight weeks of low intensity aerobic exercise on plasma levels of VIP hormone, blood pressure and heart rate in healthy elderly men and women, and patients with coronary artery disease (CAD).Methods: In this study, 15 healthy women and 15 healthy men and 15 female and 15 male with CAD disease were randomly chosen as the experimental and control groups.Subjects did aerobic exercises tree days/week, for eight weeks, with the heart rate of 100±10 beats per minute. Blood samples were taken from each subject in three stages, (before, immediately after and 24 hours after the 8 weeks of exercising).Results: The results showed that there was a significant difference among plasma VIP levels in the four groups. Moreover, a significant difference was observed between the systolic blood pressure in the four groups (P=0.01) and the systolic blood pressure in male patients and healthy women (P=0.03) while there was no meaningful difference the systolic blood pressure in the two other groups. There was also a significant difference in the heart rate of the three rounds of sampling in the three of groups (P=0.002) but no significant difference was observed in healthy men.Conclusion: According to the above results, it seems that the duration and intensity of each workout should be considered to reach the VIP stimulation threshold. It may bring about considerable changes in VIP levels.

Background: Although tracheostomy is not performed as frequently as in adults, it is also used in children. There is no clear consensus on timing and risk factors, especially in early infancy and in cases who underwent cardiac surgeries. In the early infancy period, pediatric cardiac surgery patients have to receive an inotropic agent after the cardiac surgery due to poor general condition or hemodynamic instability. As a result of prolonged intubation, tracheostomy is required to be performed in some of these patients. Objectives: The present study aimed to investigate the relationship between VASOACTIVE inotropic scores (VIS) and tracheostomy in pediatric cardiac surgery patients. Methods: A total of 47 patients, 21 with tracheostomy and 26 without tracheostomy, who underwent cardiac surgery were included in this retrospective study. The VIS and inotrope score (IS) values were calculated and recorded hourly for 48 h postoperatively. Scores were calculated by multiplying the inotropes infusion rate of the patients with certain coefficients. It was attempted to determine objective formalized models and cut-off values that may benefit the relationship between VIS values and tracheostomy. Results: The median weight was 3, 630 g (range, 2, 040-13, 400), and the median age was 69 days (range, 1-1, 081) on the surgery day. The majority (93. 6%) of the patients were aged < 1 year. Preoperative C-reactive protein measurements were significantly higher by 50% in patients who underwent tracheostomy (P=0. 005). The albumin levels in the tracheostomy group (TG) were low, although not significantly (P=0. 057). The VIS values of TG had 50% higher values than the non-tracheostomy group (NTG) (P<0. 001). In addition, formula 1 predicted with 57% accuracy that a tracheostomy could be performed (VIS =18. 170-0. 170* HOUR,P < 0. 001), and formula 2 predicted with 72% accuracy that a tracheostomy could not be performed (VIS =17. 170-0. 170* HOUR,P < 0. 001). Hospital stay (P<0. 001), mechanical ventilation duration (P<0. 001), and the number of ongoing intubation on the 7 th day post-surgery were significantly higher in TG. Conclusion: After pediatric cardiac surgery, VIS values can predict tracheostomy status and help intensive care professionals make decisions.