The study of the role of lipids in various physiological functions was made indirectly for the most part, using the tests previously mentioned which were interpreted in terms of dualistic patterns. These were related to the general offbalances A and D and, through them, attributed ultimately to a predominance of sterols or fatty acids.

Sleep in itself, without relation to night or day, was found to induce a marked change, comparable to a type A offbalance with predominance of sterols. Subjects with pain of an acid pattern often correlate the appearance of pain with sleep, the pain occurring uniformly at the moment they wake up. In these cases, the urine shows a low specific gravity with a high pH and a high surface tension, corresponding to an A type off balance. As we will see, in subjects with an intensive A type offbalance, nocturnal polyuria and pollakiuria occur.

Sexual intercourse in males was seen to induce, in analyses, transitory changes similar to an offbalance of type D, corresponding to a predominance of fatty acids. In females the change corresponds to a transitory off balance of type A, manifested by changes at the systemic level. Muscular exercise was seen to induce, in a first phase during the exercise itself, changes comparable to an offbalance type D. This phase is followed by a much longer phase of type A, indicating sterol predominance. Intensive mental exercise produces a marked change similar to offbalance A, with all urinary tests showing the patterns found with predominance of sterols.

 The disappearance time for the wheal induced by the intradermic injection

Fig. 68. The disappearance time for the wheal induced by the intradermic injection of 0.2 cc saline, varies with the age. In old age, the wheal often persists for more than 90 minutes.

The responses attributed to influences exerted by external factors could be integrated in the same dualistic mechanism. All the data indicate the manifest influence exerted by the time of day. Two marked changes are seen, one around four o'clock in the morning and the other usually around eight or nine o'clock in the evening. The morning change corresponds to a predominance of sterols, the evening to predominance of fatty acids. These changes together with the clinical manifestations related to time of day appear in a new light when interpreted not as being the direct results of time changes but rather of patterns of diurnal activity and nocturnal rest. This explains why in rats and mice, which are nocturnal animals, most of the analyses show variations related to the time of day opposite to those in humans. Other variations could be recognized more strongly related to time of day. Variations with a 24-hour rhythm could be seen, for instance, for urinary surface tension in mice. But, when rats and mice were maintained for a length of time under artificial conditions, with light during the night and dark during the day, the animals changed their habits, becoming active during the day and sleeping during the night. After a certain time, most of their analytical patterns such as urinary pH, blood leucocytes, eosinophiles etc. changed, acquiring the type of variation seen in humans. Urinary surface tension remained unchanged for a long time. (Note 8 Chapter IV) Even more interesting were other changes which could be related to changes in external temperature. The urinary surface tension measured in rats in the morning for long periods of time showed variations related to changes in the temperature of the environment. (Note 26) (Fig. 69)

The importance of temperature led to its more detailed investigation. Variations in lipidic balance have been found to parallel variations in body temperature. The blood of normal individuals is richer in sterols than the blood of those with hypothermia. Furthermore, in moments of high temperature, more sterols are found than in moments of low or normal temperatures. An increase of fatty acids occurs in conditions with hypothermia. These changes were confirmed also by the correlation between blood content in lipids and temperature in different abnormal conditions. In shock with hypothermia the blood is rich in fatty acids, while in infections with fever, it is rich in sterols.

The role of temperature was also investigated by studying the influence upon the lipidic balance by externally applied heat or cold. Characteristic variations could be seen in human analyses under the influence of hot and cold days, and of local applications of heat and cold. Manifestations corresponding to predominance of lipids with positive character were induced by heat, while others corresponding to predominance of lipids with negative character were induced by cold. Variations were seen in animals kept in an incubator or in a refrigerator. (Note 27) We will see below, by studying their influence at different levels, the importance of these variations produced by temperature.

The influence exerted by barometric changes could be seen in changes in total blood potassium, the two curves being parallel. Similar changes could be observed related to the atmospheric humidity. Other tests as well, such as urinary pH, calcium excretion, etc., show a similar relationship but to a much lesser degree. (Note 28) The influence exerted by the environment could explain the changes seen from one day to the other in various analyses. (Note 28)

The curves of the average values of surface tension of two groups of 20 male rats each

Fig. 69. The curves of the average values of surface tension of two groups of 20 male rats each, and two groups of female rats each, show parallel changes with the inverse curve of the temperature of the environment.

The influence exerted by changes in seasons was studied. An increase in fatty acids in winter and of sterols in summer could be noted. These increases also could be largely related to the seasonal variations in temperature. Very hot days were marked by analyses indicating intervention of lipids with a positive character. The influence exerted by the seasons was seen even in the responses of organisms to pathological conditions such as tumors; variations in character and growth of experimental cancer could be noted. (Note 29) The relationship of many viral infectious diseases to seasonal changes which has been noted in many epidemiological studies could be related to the changes in lipids. (Note 30)

Effect Of Antagonistic Lipids At Different Levels

A more complete study of lipids under the dualistic concept was made by considering their activity at different levels of hierarchic organization. This research was greatly facilitated by the degree of individuality which different biological levels exhibit when they are part of the hierarchic organization of complex organisms. It was also aided by the availability of lower organisms in nature which correspond to various hierarchic levels. Through this double approach, the information obtained showed the importance of the relationship between the levels of the complex organism and the influence exerted by lipoids. If high doses of the agents are applied, the influence is exerted upon all the levels. A preferential influence is exerted upon a single level if reduced doses are used. When medium size doses are administered, to the preferential effect upon one level a reactional response at other levels is added. This results often in concomitant opposite effect at these levels.