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Nonpolar and polar lipids extracted from denervated rat gastrocnemius, plantaris, and soleus muscles were measured 7-9 days after unilateral sciatic nerve transection. The contralateral muscle (CCON) was used to obtain control lipid levels. After denervation changes in lipid concentrations were found in all three muscles. These alterations in lipid levels were generally in same direction but not to the same extent. The change in total nonpolar lipids (NL) was an increase in soleus greater than gastrocnemius greater than plantaris concentration. This change in lipid concentration was more apparent than real since the wet weight of muscle was decreased after denervation. Since polar lipid (PL) concentrations were not increased under these conditions of muscle weight loss, an actual decrease of polar lipids after denervation may be inferred. In contrast to the other two muscles, a marked difference was noted for polar lipids of denervated gastrocnemius muscle. An unidentified spot near the origin was detected. This area is the location of a nerve sprouting factor(s). The compound(s) was not detectable for the other two muscles. When the gastrocnemius from an unoperated animal rather than a CCON muscle was used as a benchmark, slight increases were found for total nonpolar, polar, and plasmalogen fractions following denervation. The changes for individual lipid fractions were less definable, except for the significant increase for the unknown polar compound near the origin. This spot was noted in extracts from CCON and DEN muscles but not in untouched control muscle. The CCON gastrocnemius muscle is therefore a poor control for determining effects of denervation on lipid levels and perhaps other biochemical parameters as well.

Crude lipids extracted from Naja naja were separated by column, thin-layer and gas-liquid chromatography. Cholesterol was found to be the chief neutral lipid (10 per cent of total). Phosphatidyl choline (lecithin) represented 83 per cent of the total and was the only phospholipid detected. The fatty acid content of neutral lipids represented saturated acids, while the phospholipids had a predominance of unsaturated fatty acids.

SummaryMouse brains were extracted with a variety of solutions composed of inorganic salts, organic solvents, or mixtures of each. During these experiments, it was noted that a differential effect of certain salts and solvents on isozyme patterns could be demonstrated. These effects of isozyme systems [lactic dehydrogenase (LDH) and nonspecific esterase] could best be explained on the basis of lipid-enzyme complexes. Circumstantial evidence is provided for viewing LDH as a lipoprotein catalyst.

SummaryThe amount of cholesterol in brain tissue of male mice (5–10 weeks old) can be lowered by intraperitoneal injection of small amounts of Ritalin. Maximum effect occurs twenty-four hours after the initial dosage. Adjustment to normal levels occurs in the ensuing 48 and 72 hour periods. It is hypothesized that the stimulating effect of analeptics is related to brain sterol metabolism.

Dietary lipids, in particular unsaturated fat, promote the development of many experimental tumors. However, no mechanisms to fully explain these effects have been elucidated. Recent reports, which we summarize here, suggest a role for gap junction-mediated intercellular communication in the process of tumor promotion. We also review tumor-promoting effects of dietary fat on experimental, particularly mammary, carcinogenesis. Our main focus is to review recent data examining the inhibitory effects of unsaturated fatty acids on metabolic cooperation in Chinese hamster V79 cells. These data suggest that inhibition of junctional communication may be involved mechanistically in the promotion of tumors by high levels of dietary unsaturated fat. Finally, potential mechanisms by which unsaturated fatty acids inhibit metabolic cooperation are examined.

Twenty-four-hour urine was collected from normal and dystrophic mice and hamsters for catecholamine determinations. A new method of analysis was used whereby 3,4-dihydroxyphenylalanine (DOPA), dopamine (DA), norepinephrine (NE), and epinephrine (E) were measured simultaneously. The procedure is based on a combination of liquid-solid extraction, cation exchange chromatography, and controlled potential electrochemistry. The results of these experiments indicated that while DA levels were similar in both normal and pathological animal urine, DOPA levels decreased slightly in the dystrophic mouse but not the hamster, and NE and E levels in dystrophic groups were two and four times greater than normal in both species. The data supports the concept of biochemical alterations in tissue other than muscle. While not necessarily supportive to catecholamine abnormality as the primary cause of muscular dystrophy, the present data cast doubt that this disease is a primary muscle disease.

SummaryThe effect of a single injection of methylphenidate (Ritalin, 4 mg/kg) on precursor ([2-3H]acetate and [U-14C]glucose) incorporation into brain cholesterol was studied. The drug caused a steady decrease in the concentration of brain cholesterol during the 24-hr period examined. Incorporation studies during this time with [U-14C]glucose indicated higher than normal incorporation for all time periods studied. The most significant incorporation increases took place 2 and 4 hr after drug injection. Experiments using [2-3H]acetate as the sterol precursor gave incorporation values which tended (not significantly) to be lower than control values at 2 and 4 h. The values after 12 hr were less than normal, while the 24-hr group indicated an increase to or slightly higher than normal values.These data suggest that the pharmacological effect of methylphenidate may be due to lowering of brain cholesterol levels directly or on some more basic metabolic process leading to a decreased level of membrane sterols.

SummaryThree genetic groups of mice (DyDy, Dydy, and dydy) were studied at intervals of 6–14 wk. TCA intermediates were extracted, separated, and measured. Data indicate that mice with genetically induced muscular dystrophy (Strain 129) show alteration in several body tissues as well as in muscle itself. Of particular interest were changes measured in the brain of dystrophic mice. Support, but not proof, is given to the neurogenic concept of mouse muscular dystrophy.

Isozyme patterns of cholinesterase (ChE) from heart, tongue, and skeletal muscle of normal and dystrophic hamsters are presented. Two principal bands, bands 1 and 2, were evaluated. Band 1 migrates faster towards the anode than does band 2. While bands 1 and 2 stain for AChE and were found in control muscles, only band 2 was stained by a pseudocholinesterase (BuChE) and was decreased in samples from dystrophic hamsters. The decrease in BuChE was most pronounced in dystrophic heart muscle. The low level of BuChE measured for dystrophic animal tissue was similar to isozyme patterns found in embryonic tissue and in denervated muscle. BuChE obtained by acrylamide gel electrophoresis along with 16S AchE appears to be a useful biochemical marker of nerve-muscle interactions.

The low molecular weight components of Elapidae venoms were investigated. The first separations of snake venom toxins by thin-layer chromatography (TLC) on silica gel were achieved. Sixteen Elapidae venoms were compared by starch gel electrophoresis and TLC. Almost three-quarters of the venom was dialyzable. The adsorption of toxins onto the larger protein molecules in snake venoms was demonstrated by measuring dialysis rates as well as showing that homogeneous electrophoretic bands yielded multiple spots by TLC. The feasibility of separating the low particle weight toxins of Elapidae venoms by silicic acid TLC and column chromatography was demonstrated. A low molecular weight toxic principle of Naja naja was isolated, partially characterized, and shown to be one of the most lethal materials isolated from biological sources (ld50 = 0·03 mg per kg).

Glucose-1 and glucose-6 labeled with tritium or carbon-14 were incorporated in vivo into brain and liver sterol. Differential incorporations of glucose labeled in both positions were compared. A higher than expected incorporation of C-1 from glucose was noted.

Clofibrate can both inhibit and stimulate the oxidation of succinate by mouse liver mitochondria, depending on whether the salt or the esterified form of the drug is used. Sodium clofibrate is a strong inhibitor whereas clofibrate ethyl ester is an active stimulator of succinate oxidation by mouse liver mitochondria.

The appearance of methyl esters of fatty acids in lipid extracts was studied. Experimental evidence indicates that these esters are both natural components of tissues as well as products of technical manipulation. Effect of temperature on the latter process was studied. The results of these experiments show that the post-mortem increase of fatty acid methyl esters could best be explained by postulating an enzymatic rather than a chemical process.

During the past decade, our laboratory has been involved in studying the biosynthesis of brain cholesterol under various conditions. As a result of these studies, we feel that the hypothesis of metabolic stability of cholesterol in adult life is untenable. Our data suggest that there are several compartments of sterol metabolism ranging from extremely fast to metabolically very slow. It is our hypothesis that (a) brain function is more nearly associated with fast turnover compartments than with metabolically slow ones; (b) these compartments can be altered by a variety of stress conditions.

Conclusions1. Various resorcinol derivatives of a non-toxic nature have been shown to be active against EEE virus under in vitro conditions. 2. Some factors affecting inactivation of EEE virus by 2,7-diiodotetraiodofluorescein have been presented and their importance in an in vitro study on compound-virus interaction stressed. 3. An in vitro screening technic has been demonstrated permitting the study of the effect of compound configuration on virus activity.