Hyperlipoproteinemia in experimental chronic renal insufficiency in the rat

Lipid metabolism was studied in experimental uremia. Uremic (U) rats were compared with sham-operated, pair-fed (PF) controls and with ad-lib-fed (AL) controls. In U animals, fasting glucose concentrations were normal, immunoreactive serum insulin (IRI) levels were decreased, and immunoreactive glucagon levels were increased. A significant increase in the serum concentration of all lipid classes was observed: triglycerides were elevated 10-fold above the values in PF and AL controls; phospholipids, twofold; total cholesterol, threefold; and free cholesterol, sixfold. Cholesterol concentration was increased in beta- and pre-beta-lipoproteins and even more so in alpha- and pre-alpha-lipoproteins. There was an increase in the ratio of free cholesterol/total cholesterol. The fatty acid composition of serum lipoproteins was unchanged. Concomitantly, in liver tissue, there was no change in lipid content (triglyceride, cholesterol) and fatty acid composition. These findings argue against glucose- or insulin-mediated changes in hepatic de novo fatty acid synthesis, chain elongation, or poly-desaturation. In U animals, the HMG-CoA-reductase activity of liver microsomes was slightly, but not significantly, reduced as was tritiated water incorporation into cholesterol in isolated perfused liver preparations. In adipose tissue, there was a decrease in triglyceride content. The results provide evidence against insulin-mediated hepatic overproduction as a major cause of hyperlipoproteinemia in this model of experimental renal insufficiency and point to peripheral under-utilization of lipoproteins.

[Simultaneous determination of free cholesterol and total cholesteron on an AA I Technicon autoanalyzer (authors transl)]

A procedure for the simultaneous enzymatic determination of free cholesterol and total cholesterol on a 2 channel AA I Technicon autoanalyzer system is described. The quantitation of free cholesterol is compared with the determination by gas chromatography. The investigation reveals a high correlation between both methods. In contrast to classical procedures the proposed quantitation of free cholesterol can be performed easily and quickly for routine analyses.

[Ernst Mach and the development of the physiology of the retina (author's transl)]

This article gives an evaluation of Ernst Mach's contribution during the period from 1865-1868 to the field of sensory physiology with special reference to the development of retinal neurophysiology.

Effect of prolonged glucose infusion on total serum fatty acids and free fatty acids in the rat

This investigation evaluates the effect of prolonged glucose infusion on triglycerides and the composition in total serum fatty acids and free fatty acids in the rat. Glucose infusion over a period of 4 days leads to the following changes: serum triglyceride concentrations are two to three times elevated and serum insulin levels rise 10 times after 12 hours, followed by a steady decrease. Chain elongation is depressed in serum free fatty acids and even more in total serum fatty acids. In serum free fatty acids monodesaturation is unaltered whereas it is highly stimulated in total serum fatty acids. These alterations correlate with the changes of hepatic total fatty acids and do not correlate with changes of fatty acids from epididymal fat pads. The alterations reflect a specific carbohydrate-induced effect on hepatic fatty acid desaturation and chain elongation. They do not support the idea that serum free fatty acids are mainly secreted from the storage pool of adipose tissue; yet, they may have been newly synthesized in fat cells or even in the liver.

Automatic potentiometric titration and gas-liquid chromatography of underivatised free fatty acids

A rapid and precise method is described for the determination of total free fatty acids (FFA) in the serum followed by the separation of individual FFA by gas-liquid chromatography (GLC). After the extraction the FFA are directly injected into the gas-liquid chromatograph without esterification. DEGS-PS serves as stationary phase. The esterified fatty acids such as cholesterol esters, phospholipids or triglycerides do not interfere with the FFA determined by the GLC method. This method is compared to other commonly used titrimetric and gas-chromatographic procedures. The changes of the composition of individual FFA during and after ergometer work is reported.

[Copper-7 intrauterine device (Gravigard). Report of experience]

Within 2 years 258 women aged 16 to 42 years were fitted with a copper-7-IUD (Gravigard, Searle). 45% of these patients were nulliparous women. Follow-up studies were provided in 236 cases in a total of 2717 women-months according to an average time of observation of 11.5 women-months per patient. Altogether there occurred 5 unwanted pregnancies with a Pearl-Index of 2.3. Partial or total expulsion occurred in 27 cases (11%). Fourteen out of 27 expulsions were noticed within the first 2 months after insertion. Removals for medical reasons were requested in 36 cases-in the majority (26 cases) because of bleeding and pain. Thirteen women desired removal of the IUD in order to get either pregnant or sterilized. The continuation rate after 2 years was 73%. The highest number of drop-outs occurred within the first year after insertion (60 cases = 23%) whereas only 4% drop-outs occurred in the 2nd year. It was suggested that the low continuation rate might be partially due to the high number of physicians (19) participating in this study. The most important side effects of the copper-7-IUD in situ were irregular bleeding, intermenstrual pain and discharge. Irregular bleeding and pain decreased markedly after the first year, while slightly prolonged periods persisted in 30 to 50% of all patients. Compared with oral contraceptives copper IUDs hav less severe side effects but less safety at the same time-especially for the younger fertile age group. Therefore they should be offered to young nulliparous women only for a limited period of time.