E. F. Taskier in collaboration with the author, has studied the intervention of adrenals in the defense against various fatty acids. (231)

It is known that the adrenals have an important role in the defense of the organism against noxious agents, a normal animal being more resistant to toxic effects than an adrenalectomized one. Systematic study of adrenal intervention has shown that it occurs with a certain degree of specificity.

The method of investigation used was the following: inbred Wistar rats of the same sex and approximate body weight of 150 gr. were adrenalectomized. The surgical procedure was carefully standardized, lasting less than two minutes, and producing a minimum of trauma. This was made possible by the Noyes Fixation Forceps which is utilized in ocular surgery and is well suited to pick out the adrenal gland without damage to it or to neighboring tissue. As controls, animals of the same weight and sex were sham operated. On the third postoperative day, the agent to be tested was injected intraperitoneally. At this time, the organism had recovered from the immediate traumatic effects of the operation and no manifest adrenal deficiency symptoms were as yet present. Only those deaths occurring up to 48 hours postchallenge were considered to be due to the direct toxic effects of the substance. Deaths occurring more than 5 days after adrenalectomy could be attributed to effects of the adrenal deficiency itself, and for this reason, were not included in the experiment.

The minimal Lethal Dose for each agent was determined by using progressively increasing doses. This was done separately for adrenalectomized and for control animals. It was the difference in the toxicity in sham operated and in adrenalectomized animals that was considered rather than the toxicity of the substance itself.

The ratio of the Minimal Lethal Dose for the two groups of rats, sham operated and adrenalectomized, was calculated. It furnished a numerical representation of the degree of adrenal intervention and was called the "Adrenal Defense Index" or A.D.I. We utilized this index. MLD Sham operated /MLD Adrenalectomized, as a measure of the reIative adrenal participation in the body defense against different substances. A low index points to a general nonspecific response; a higher index indicates a more significant intervention.

We obtained the adrenal defense index for various groups of fatty acids. They included homologous series of saturated, unsaturated, alpha OH and conjugated fatty acids. Over 900 rats were used in this study.

For the saturated fatty acids we found:

FATTY ACID

A.D.I.

Caproic acid

2.5

Caprylic acid

5

Capric acid

5

Lauric acid

1.5

Myristic acid

2

Palmitic acid

12

Stearic acid

6

We interpret this to mean that the defense capacity of the organism against these fatty acids was only slightly more effective in the sham operated than in the adrenalectomized animals. The adrenals did not seem to be especially active in the defense against these substances.

For the unsaturated fatty acids we found:

FATTY ACID

A.D.I.

Oleic

6

Linoleic

9

Linolenic

5

These values indicate more active adrenal intervention agamst these fatty acids.

For the saturated alpha OH fatty acids the results were:

FATTY ACID

A.D.I.

alpha OH Caproic Acis

4.5

alpha OH Caprylic Acid

4

alpha OH Capric Acid

3

alpha OH Laurie Acid

20

alpha OH Myristic Acid

9

alpha OH Palmitic Acid

3

alpha OH Stearic Acid

50

We choose this series of substances because Camien and Dunn, and others, have shown the importance of these fatty acids for bacterial growth, as well as the presence of alpha OH lauric and alpha OH myristic acids as part of the lipido polysaccharide fraction of bacteria.

Through related research, we were particularly interested in the A.D.I, value of fatty acid molecules with conjugated double bonds. As conjugated diene, we administered conjugated linoleic acid. The A.D.I, of this substance was similar in value to that of its nonconjugated isomer. The index was 5. For the conjugated triene, we used eleostearic acid obtained from tung oil. The results were striking. We found an A.D.I, value of 120. The A.D.I, of this acid thus showed a 24-fold increase over the index of its nonconjugated isomer.

The data indicate a degree of specificity for the adrenal defense mechanism. A.D.I, values of 3 or less could be interpreted to correspond to a nonspecific adrenal intervention toward fatty acids in general, while higher values indicate a larger, probably specific adrenal activity. In the case of alpha OH lauric and alpha OH stearic acids, the high A.D.I, values could be releated to the fact that these fatty acids have been found to be part of the constitution of bacteria.

The intensive defense evidenced by the high A.D.I, value for eleostearic acid is related to the appearance of conjugated trienes during the course of certain pathological conditions, especially trauma. The continuous increase, especially of conjugated trienes, in the adrenalectomized animals suggests that these fatty acids appear in the organism but are destroyed under normal conditions. They accumulate, however, in adrenalectomized animals and may contribute to death when they reach a certain critical concentration. It is possible that with additional administration of these conjugated trienes their critical concentration would be reached and the animals would die.

In the light of these data, we investigated the role of different adrenal factors in these responses. Cortisone, deoxycorticosterone acetate (DOCA), and sodium chloride were tested for their protective action against the toxic effects of oleic and eleostearic acids. Groups of rats were treated immediately after adrenalectomy with daily doses of 1 mg. of cortisone, two tenths of a cc. of DOCA, or 1 % NaCl drinking water ad libitum. Control adrenalectomized rats were given no sustaining therapy. Three days after adrenalectomy, a challenging intraperitoneal dose of 1 cc. of 10% oleic acid per 150 gr. of body weight was administered.

Whereas the mortality of the control rats was 90%, it was 25% in the cortisone treated animals. DOCA administration decreased the mortality only to 65% and NaCl had little effect, decreasing it only to 85%.

The protective effect against oleic acid in adrenalectomy is seen in the following table:

AGENT

% MORTALITY

Control

90

Cortosone

25

DOCA

65

NaCl

85

This suggests that the neoglucogenic hormone plays a significant protective role in the defense of the organism against the noxious effects of fatty acid. The mineralocorticoid, on the other hand, seems to play a lesser role in this mechanism, a fact which is confirmed by the ineffectiveness of sodium administration.

A similar preliminary experiment carried out for eleostearic acid shows the same protective effectiveness of cortisone, lesser effectiveness of DOCA and almost no effect at all of sodium chloride.

Chapter 6, Note 19. Bonds Of Glucuronic Acid

The study of the detoxifying excretion of different agents led to the following conclusions. Primary aliphatic alcohols—except methyl alcohol —are eliminated coupled by glucuronic acid; the same for the secondary aliphatic alcohols; tertiary aliphatic alcohols and glycols from propylene glycol up. Of the aliphatic aldehydes only a few are coupled and only after transformation in vivo. While most of the aliphatic ketones are coupled, phenol and more emphatically the cresols and salicylic acid are in part excreted as sulfo coupled, and only in part as glucurono coupled. Resorci nol, catechol, orcinol, phenolphthaleine, phloridzin are mostly eliminated as glucurono coupled, while adrenaline almost solely as sulfate. Most of the aromatic hydrocarbons are also bound to glucuronic acid, but only after having been changed in vivo.

For the aromatic acids, the bond to glucuronic acid is conditioned by the presence of second polar groups, usually one or more hydroxyls. The aromatic nitrogen compounds are first changed into amino groups before they are coupled with the glucuronic acid. Only relatively small amounts of sulfonamides were excreted bound to glucuronic acid.

Many of the heterocyclic compounds are bound to glucuronic acid with the condition to have amino or hydroxyl groups; the same for the sex hormones, the estrogens being the group especially excreted as such.

The general characteristic of the substances excreted as coupled with glucuronic acid is the presence in their molecule of one or more positive polar groups hydroxyl or amino. As with few exceptions all these substances have also lipoidic properties, the excretion coupled to glucuronic acid appears as a means to eliminate positive lipoids.