Modulation of nociception by medial pre-optic area orexin a receptors and its relation with morphine in male rats

INTRODUCTION

Recent studies have shown that medial pre-optic area (MPOA) of hypothalamus are involved in nociception. Orexin A (hypocretin 1) has been found to have numerous applications including pain modulation. However, the role of orexin A receptors in the MPOA on the nociception has not been yet studied. Therefore, the aim of the present study is to investigate the effect of orexin A microinjection on MPOA on the nociception transmission and morphine induced analgesia in adult male rats.

METHODS

Using stereotaxic surgery, a cannula was implanted at a site 1mm above the MPOA in the anesthetized rats. After the recovery period, tail-flick (TF) latency was measured as 0, 15, 30, 45 and 60min following the onset of two experimental protocols. Two experiments were carried out. Experiment 1: The male rats received intra-MPOA of 25, 100, 1000, 10000pmol/0.5μl orexin A or 0.5μl of aCSF (control, just 5min before the TF assay. Experiment 2: The aim of this experiment was to examine the effect of orexin microinjection into MPOA on morphine analgesia (3mg/kg,s.c). Morphine was administered 30min before orexin A intra-MPOA microinjection (four doses similar to experiment 1) or aCSF, then TF latency was measured.

RESULTS

The results indicated that microinjection of orexin A into the MPOA showed anti-nociceptive effect in a time-dependent manner. Dose response curve results also revealed that the maximum effective dose of orexin A injection into MPOA for pain inhibition is 1000pmol/0.5μl. Co-administration of systemic morphine and orexin into the MPOA has additive analgesia with different time course compared morphine or orexin alone.

CONCLUSION

It can be concluded that MPOA OrexinA receptors play an important role in the modulation of pain in normal and morphine treated male rats.

Prevalence of tobacco use among adult and adolescent females in Egypt

Egypt assessed tobacco use among young people and adults through implementation in 2009 of the Global Youth Tobacco Survey (GYTS) among school students aged 13-15 years and the nationally representative Global Adult Tobacco Survey (GATS) among adults aged 15+ years. Both surveys employed cluster sampling to produce nationally representative samples and used standard core questionnaires with optional, country-specific questions. The results indicated that a higher percentage of adolescent girls in Egypt used tobacco than did adult females. Overall, 3.8% of girls aged 13-15 years used some form of tobacco compared with 0.6% of women aged 15+ years. Adolescents were over 14 times more likely than adult women to currently smoke cigarettes and 11 times more likely to smoke waterpipes. Moreover, the prevalence of cigarette smoking among adolescent girls had increased from 1.4% in the 2005 GYTS to 2.8% in 2009, indicating that social and cultural norms may be changing.

Public opinion on smoke-free policies among Egyptians

SETTING

A smoke-free law was passed in Egypt in 2007. In 2010 a bylaw was issued, leading to a drive by the Ministry of Health and Population (MOHP) to launch a smoke-free initiative in Alexandria, the second largest city.

OBJECTIVE

To assess public opinion with regard to 100% smoke-free legislation and its implementation in the Alexandria governorate.

DESIGN

The Union Middle-East Office, in collaboration with the Central Agency for Public Mobilization and Statistics and the MOHP, conducted a cross-sectional survey among 427 randomly selected adults (206 males and 221 females), covering the seven major districts of the Alexandria governorate.

RESULTS

The majority of the interviewed subjects (98%) expressed support of the government in enacting 100% smoke-free indoor legislation in all public places and public transport. Respondents endorsed the government plan to implement legislation imposing 100% smoke-free public places. More than one third (33.5%) of all respondents indicated that they would increase visits to restaurants if they were smoke-free, and 63% indicated no impact at all.

CONCLUSION

The results of the poll clearly support results from different countries worldwide that smoke-free policies are popular and supported by the public.