To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Ethological and ecological studies of wild animals are producing evidence for metabolic stress during courtship, breeding and parental care comparable with that of domestic livestock. Resistance to disease may be compromised by the demand for fatty acids and proteins during reproduction and even more during lactation. The adipose tissue around major lymph nodes is indistinguishable histologically from that in larger depots. In vitro and in vivo studies reveal that it is specialized to respond to lipolytic agonists secreted by lymphoid cells but is insensitive to the endocrine conditions of short-term fasting. These properties enable it to provision adjacent immune cells. Such adipose tissue may act as a forum for competing demands of mammary glands, muscles etc. and local defences against pathogens. Glutamine is essential to the nutrition of the immune system and is used by the mammary gland. Muscle is the best known source but adipose tissue also participates in glutamine metabolism and may become more important in animals in which the musculature is wasted through prolonged lactation.
A three week low calorie diet significantly reduced both total plasma tryptophan and the ratio of tryptophan to competing amino acids in a group of 15 healthy volunteers. Despite a similar percentage weight loss the reduction in plasma tryptophan was greater in women than men. In addition, only in women was dieting associated with increased prolactin secretion following intravenous tryptophan, a measure of brain 5-hydroxytryptamine (5-HT) function. These results suggest that dieting reduces the availability of circulating tryptophan for brain 5-HT synthesis. Women appear more vulnerable than men both to this effect and to its consequences for brain 5-HT function. Altered brain 5-HT function may play a part in some of the psychological consequences of dieting, including the development of clinical eating disorders.