Sebaceous gland response in man to prolonged total caloric deprivation.
TL;DR: The response of the sebaceous gland to total caloric deprivation was studied in 18 obese patients undergoing fasts for periods of four to eight weeks and was found to decrease in each individual, with an average reduction of 40%.
About: This article is published in Journal of Investigative Dermatology.The article was published on 1970-11-01 and is currently open access. It has received 95 citations till now. The article focuses on the topics: Sebaceous gland & Triglyceride.
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TL;DR: This review seeks to present an update on the physiology of the sebaceous glands, with particular emphasis on the production ofsebaceous lipids.
314 citations
Cites background from "Sebaceous gland response in man to ..."
...The uptake of circulating lipids is also suggested by the observation that upon beginning a fast, the incorporation of free fatty acids into sebum is reduced by 20% (24, 25)....
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TL;DR: Understanding the factors and mechanisms that regulate sebum production is needed in order to identify new targets that could be addressed to achieve a selective modulation of lipid biosynthesis as a novel therapeutic strategy to correct lipid disregulations in acne and other disorders of the pilosebaceous unit.
Abstract: The principal activity of mature sebaceous glands is producing and secreting sebum, which is a complex mixture of lipids. Sebum composition is different among species and this difference is probably due to the function that sebum has to absolve. In human sebum there are unique lipids, such as squalene and wax esters not found anywhere else in the body nor among the epidermal surface lipids. Moreover, they correspond to major components supplying the skin with protection. However, the ultimate role of human sebum, as well the metabolic pathways regulating its composition and secretion rate, are far from a complete understanding. Increased sebum secretion is considered, among all features, the major one involved in the pathophysiology of acne. Along with increased sebum secretion rate, quali- and quantitative modifications of sebum are likely to occur in this pathology. Understanding the factors and mechanisms that regulate sebum production is needed in order to identify new targets that can be addressed to achieve a selective modulation of lipid biosynthesis as a novel therapeutic strategy to correct lipid disregulations in acne and other disorders of the pilosebaceous unit.
253 citations
Book•
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08 Dec 1992
TL;DR: This enlarged and revised edition covers all aspects of acne, acne-like disorders and rosacea and places special emphasis on their histopathologic examination.
Abstract: This enlarged and revised edition covers all aspects of acne, acne-like disorders and rosacea. It is designed for those physicians - general practitioners, paediatricians, gynaecologists, pharmacologists, surgeons and dermatologists - who must identify and treat the many different forms of these diseases. It not only covers the physiology, pathology, bacteriology and endocrinology of these disorders, but also places special emphasis on their histopathologic examination. The text is supplemented by selected references and an illustrated portfolio of gross and histopathological pictures. The latest therapeutic strategies as well as conventional options are covered. The spectrum of pharmacological and physical methods of controlling acne, acne-like diseases and rosacea are critically examined.
215 citations
TL;DR: This review summarises the latest advances in understanding the role of sebaceous gland cells in the pathomechanism of acne and highlights the importance of knowing the carrier and removal of canine coronavirus.
Abstract: The pathogenesis of acne, a disease of the pilosebaceous follicle and one of the most common chronic skin disorders, is attributed to multiple factors such as increased sebum production, alteration of the quality of sebum lipids, inflammatory processes, dysregulation of the hormone microenvironment, interaction with neuropeptides, follicular hyperkeratinisation and the proliferation of Propionibacterium acnes within the follicle. In particular, the sebaceous gland plays an exquisite role in the initiation of the disease as it possesses all the enzyme machinery for the production of hormones and cytokines. In addition, in response to the altered tissue environment in the pilosebaceous follicle as well as in answer to emotional fret, stress response system mechanisms with induction of central and local expression of neuropeptides, are also initiated. This review summarises the latest advances in understanding the role of sebaceous gland cells in the pathomechanism of acne.
207 citations
Cites background from "Sebaceous gland response in man to ..."
...On the other hand, extreme caloric restriction dramatically decreases the sebum excretion rate and these changes can be reversed when a normal diet is resumed.(14,15) Other studies have demonstrated that increased consumption of dietary fat or carbohydrate increases sebum production and modifications to the type of carbohydrate can also alter sebum composition....
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TL;DR: Findings indicate that sebum lipid fractions with proinflammatory properties and inflammatory tissue cascades are associated in the process of the development of acne lesions.
Abstract: Hyperseborrhoea has been considered as a major aetiopathogenetic factor of acne. However, changes in sebaceous gland activity not only correlate with seborrhoea but also with alterations in sebum fatty acid composition. Current findings indicate that sebum lipid fractions with proinflammatory properties and inflammatory tissue cascades are associated in the process of the development of acne lesions. The oxidant/antioxidant ratio of the skin surface lipids and alterations of lipid composition are the main players in the induction of acne inflammation. Nutrition may influence the development of seborrhoea, the fractions of sebum lipids and acne. Acne is an inflammatory disease probably triggered, among others, by proinflammatory sebum lipid fractions.
196 citations
References
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TL;DR: In this article, it was shown that decreased levels of active T3 may play a role by sparing otherwise obligated calories by decreasing metabolic needs, but this can be nullified by amino acid or protein supplementation.
Abstract: Starvation entails a progressive selection of fat as body fuel. Soon after a meal glucose utilisation by muscle ceases and fatty acids are used instead. Ketoacid levels in blood become elevated over the first week, and the brain preferentially uses these instead of glucose. The net effect is to spare protein even further, as glucose utilisation by brain is diminished. Nevertheless, there is still net negative nitrogen balance, but this can be nullified by amino acid or protein supplementation. Insulin appears to be the principal regulatory hormone. Recent data suggest that decreased levels of active T3 may play a role by sparing otherwise obligated calories by decreasing metabolic needs.
1,293 citations
TL;DR: Over 50 years ago, Benedict published his extensive monograph on the metabolism of fasting in man, in which he demonstrated that carbohydrate stores provide a small but significant component of the body's fuel for only the first few days.
Abstract: Over 50 years ago, Benedict (2) published his extensive monograph on the metabolism of fasting in man, in which he demonstrated that carbohydrate stores provide a small but significant component of the body's fuel for only the first few days. Thereafter, protein and fat are the sole sources of fuel, the former contributing 15% of the calories and the latter the balance. The primary role of fat as fuel was apparent to Benedict and his contemporaries; it is plentiful and expendable. The significance of the protein requirement, however, was less clear; in fact, it was not fully understood until nearly 20 years later when the obligatory dependence of the central nervous system on glucose was firmly established (3). Since glycogen stores in man were known to approximate only 200 g, it was readily apparent that glucose has to be derived from protein in order to maintain cerebral metabolism during a prolonged fast. More recently, our understanding of the fasted state has been further clarified by the demonstration that free fatty acid is both the major transport form of lipid leaving adipose tissue (4, 5) and a substrate that is
996 citations
TL;DR: This study quantifies the concentrations of circulating insulin, growth hormone, glucose, free fatty acids, glycerol, beta-hydroxybutyrate, acetoacetate, and alpha amino nitrogen in 11 obese subjects during prolonged starvation.
Abstract: This study quantifies the concentrations of circulating insulin, growth hormone, glucose, free fatty acids, glycerol, beta-hydroxybutyrate, acetoacetate, and alpha amino nitrogen in 11 obese subjects during prolonged starvation. The sites and estimated rates of gluconeogenesis and ketogenesis after 5-6 wk of fasting were investigated in five of the subjects. Blood glucose and insulin concentrations fell acutely during the 1st 3 days of fasting, and alpha amino nitrogen after 17 days. The concentration of free fatty acids, beta-hydroxybutyrate, and acetoacetate did not reach a plateau until after 17 days. Estimated glucose production at 5-6 wk of starvation is reduced to approximately 86 g/24 hr. Of this amount the liver contributes about one-half and the kidney the remainder. Approximately all of the lactate, pyruvate, glycerol, and amino acid carbons which are removed by liver and kidney are converted into glucose, as evidenced by substrate balances across these organs.
797 citations
TL;DR: The results indicate that lipid produced by the epidermis is an insignificant fraction of the total extractable surface lipid on areas rich in sebaceous glands, but can affect surface lipid composition on the limbs and on the trunk away from the midline.
277 citations
TL;DR: A procedure for photodensitometric quantitation of thin-layer chromatograms is described which can give a complete analysis of a mixture of neutral lipids in a single chromatogram without the necessity for reference mixtures.
270 citations