Jet-lag

Melatonin [73-31-4] C 2H N202 (31) has marked effects on circadian rhythm (11). Novel ligands for melatonin receptors such as (32) (12), C2yH2gN202, have affinities in the range of 10 Af, and have potential use as therapeutic agents in the treatment of the sleep disorders associated with jet lag. Such agents may also be usehil in the treatment of seasonal affective disorder (SAD), the depression associated with the winter months. Histamine (see Histamine and histamine antagonists), adenosine (see Nucleic acids), and neuropeptides such as corticotropin-like intermediate lobe peptide (CLIP) and vasoactive intestinal polypeptide (VIP) have also been reported to have sedative—hypnotic activities (7). 

In humans, poor sleep correlates with low plasma melatonin and can be improved by melatonin administration. This therapeutic approach has been tried especially in individuals whose sleep rhythms are disrupted by shift-work, blindness or jet-lag but its benefits are as yet unconfirmed and, in any case, the mechanisms by which it might reset sleep patterns are unclear. Of course, it must be remembered that other body... 

The most common CRDs include jet lag, shift-work sleep disruption, delayed sleep-phase disorder, and advanced sleep-phase disorder. Jet lag occurs when a person travels across time zones, and the external environmental time is mismatched with the internal circadian clock. Delayed and advanced sleep-phase disorders occur when bed and wake times are delayed or advanced (by 3 or more hours) compared with socially prescribed bed and wake times. 

Melatonin at doses of 0.5 to 5 mg taken at appropriate target bedtimes for east or west travel is becoming the drug of choice for jet lag. Melatonin significantly reduces jet lag and shortens sleep latency in travelers.50 Hypnotic agents with relatively short durations of action (3 to 5 hours) also may be used to sustain sleep during the initial adaptation to the new time zone. 

When I m steady I haul my bags upstairs and start unpacking. It was winter at home, and I ve brought too many sweaters even for an English summer. I unlock the tenant-proof cupboard, find our own clean sheets, and make up the bed. My jet-lagged flesh aches to lie down, and I mustn t I m only in England for a week, and there s a lot to do. 

We ve finished the wine rather quickly, and the jet-lag fog s creeping over me again. You said there are things for me to sign, to do with selling the Chantry ... 

How is Fergus I ask, getting up. I m sorry, I m horribly jet-lagged. I d better go home before I fall asleep. ... 

Jet lag loosens the moorings of your everyday mind. I m thinking about the ruins that are all I ve ever known of the chapel at the Chantry, the thick stumps of flint and stubby buttresses that were once walls the tarry beams and props supporting the wall of the house that once joined it the tiled floor, with the white harts and fleurs-de-lis still visible, though the grass creeps over them. Once I dug some tiles up in search of buried treasure, and found only earth and worms. 

No. I can t be thinking that. I won t think it. Some trick of jet lag, or grief, or the English air of my past. I won t think it. Of course I want to show him that he ought to be at the Chantry, that he s welcome—no, more than that that he s necessary. I need to make him think there s something there for him. But I won t say that, it s too close to the bone. 

A number of studies have investigated the potential of melatonin to alleviate the symptoms of jet lag. Melatonin has been found to be effective in 11 placebo-controlled studies in reducing the subjective symptoms of jet lag such as sleepiness and impaired alertness (Arendt 2005). The most severe health effects of jet lag occur following eastbound flights, since this requires a phase advancement of the biological clock. In a recent study, phase advancement after melatonin administration (using 3 mg doses just before bedtime) occurred in all 11... 

Herxheimer, A. Petrie, K. J. (2002). Melatonin for the prevention and treatment of jet lag. Cochrane Database Syst. Rev. CD001520. 

Breathing-related sleep disorder Circadian rhythm sleep disorder Delayed sleep phase type Jet lag type Shift work type Unspecified type... 

To mimic melatonin action and increase the half-life is the goal of melatonin receptor agonists, which are the more recent addition to the insomnia therapeutic armamentarium. These compounds, in addition to use for insomnia, may have potential application in the synchronization of disturbed circadian rhythms, sleep disturbances in the elderly, seasonal depression and jet lag, to name a few. Furthermore, studies have shown that melatonin receptor agonists do not induce any of the hypothermic, hypotensive or bradycardic effects caused by melatonin in humans [27,28]. 

I am walking in Hyde Park and here in London, April is being surprisingly kind. I am jet-lagged, but the London sun on the daffodils and forsythia in Hyde Park seems to sweep away the mental fog. No matter that a chain of mix-ups has preceded my arrival... 

Another common perturbation of the circadian clock is the jet lag, which results from an abmpt shift in the phase of the LD cycle to which the rhythm is naturally entrained. The molecular bases of the jet lag are currently being investigated [124]. The model for the circadian clock is being used to probe the various ways by which the clock returns to the limit cycle trajectory after a sudden shift in the phase of the LD cycle. 

The final category is termed the sleep-wake schedule disorders. These are seen in people who get their days and nights turned around. The most common examples are shift workers and travelers with jet lag. Additionally, in the elderly, especially those with dementia, a malfunction in the circadian biological rhythm that regulates sleep can leave them awake and alert at night but drowsy and sleeping during the day. 

The many circadian oscillators in the periphery are likely to have important influences on organ function, and circadian organization at the systems-level almost certainly has significant effects on overall health. Exciting developments at the intersection between clocks and human health support this belief. For example, cancers grow faster in arrhythmic animals (Filipski et al 2002), acute cardiovascular disease has a significant rhythmic component (Guo Stein 2003), and most of us have experienced first-hand the effects of jet lag and/or shift work. 

Reddy AB, Field MD, Maywood ES Hastings MH 2002 Differential resynchronisation of circadian clock gene expression within the suprachiasmatic nuclei of mice subjected to experimental jet-lag . J Neurosci 22 7326—7330 Schurov IL, McNulty S, Best JD, Sloper PJ, Hastings MH 1999 Glutamatergic induction of CREB phosphorylation and Fos expression in primary cultures of the suprachiasmatic hypothalamus in vitro is mediated by co-ordinate activity of NMDA and non-NMDA receptors. J Neuroendocrinol 11 43-51... 

Boulos Z. Bright light treatment for jet lag and shiftwork. In Lam RW, ed. Seasonal affective disorder and beyond light treatment for SAD and non-SAD conditions, 1st ed. Washington, DC American Psychiatric Press, 1998 253-287. 

There are several double-blind studies that support melatonin administration. For example, rapid deployment aviation groups sent to the Middle East demonstrated longer sleep duration and better test performance on melatonin than did the placebo group ( 174, 175). Arendt (173), who has had extensive experience with both controlled and uncontrolled studies, summarized the overall experience in 386 subjects, showing a 60% reduction in jet lag for eastern travel and a 40% reduction for western travel. 

Petrie K, Dawson AG, Thompson L, et al. A double-blind trial of melatonin as a treatment for jet lag in international cabin crew. Biol Psychiatry 1993 33 526-530. 

Travel and Equipment Transportation. Make travel arrangements that allow adequate time to accomodate unexpected events and allow for the unhurried setup of equipment at the survey site. The effects of jet lag become important when several time zones must be crossed and an intensive sampling schedule is planned. Avoid close connections between flights, especially when journeying to the survey site, since the equipment and luggage may... 

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