3-Hydroxy-3-methylglutaric acid and triton-induced hyperlipidemia in rats.

3-Hydroxy-3-methylglutaric acid (HMG) significantly decreased cholesterol, triglyceride and phospholipid levels in whole serum, serum beta-lipoproteins and liver of Triton-induced hyperlipidemic rats. Therapeutically 50 mg HMG/kg is equivalent to 200 mg nicotinic acid/kg in lowering all these lipid parameters. HMG may exert its hypolipidemic effect through inhibition of lipoprotein synthesis.     

3-Hydroxy-3-methylglutaric acid and experimental atherosclerosis in rats

Summary In rats 3-hydroxy-3-methylglutaric acid effectively counteracts the lipemic and atherosclerotic response of massive doses of vitamin D₂. It regressed the formation of atheromatous arterial lesions. Furthermore the significant decrease in serum -lipoprotein levels on HMG treatment could be due to decrease in VLDL triglyceride and cholesterol levels.Acknowledgments. The authors are indebted to Dr.W. Drell, President, Calbiochem, San Diego, California, USA, for generous gift of HMG and Lady Tata Memorial Trust, India, for providing financial assistance to one of us (S.Y.K.Y.).     

Formation of indolyl-3-acetylaspartic acid in rats

Summary Indolyl-3-acetylaspartic acid (IAAsp) was detected in the urine of rats given indolyl-3-acetic acid (IAA) i.p. It was ascertained that the conversion of IAA into IAAsp could be carried out not only in plants but also in animals.     

Alpha-amylase inhibitor increases plasma 3-hydroxybutyric acid in food-restricted rats

The effect on energy metabolism of delayed absorption of starch by inhibition of -amylase was examined by considering levels of plasma glucose and 3-hydroxybutyric acid (3-OHBA) in rats. Addition of -amylase inhibitor (AI) to a high starch diet delayed the plasma glucose response after feeding: peak plasma glucose levels in the control group occurred 15 min after feeding, whereas in the AI group this peak did not occur until 30 min after. The total plasma glucose response was not different between the two groups. Plasma 3-OHBA levels 1 day after food restriction increased approximately five-fold in both groups. After 3 days of food restriction, the AI group maintained the same level of plasma 3-OHBA as after 1 day of food restriction, while the control group showed significantly decreased levels of 3-OHBA. After 3 days of food restriction, plasma insulin levels were significantly decreased in the AI group compared with the corresponding levels of the control group and with levels before the restriction. There was no significant difference in body weight between the two groups. These findings suggest that delayed hyperglycemia due to delayed absorption of starch following AI loading may attenuate insulin secretion, leading to altered metabolism of 3-OHBA during the delayed response to energy deficit.     

Effect of 3-hydroxy-3-methylglutaric acid on blood lipids in normal and cholesterol-fed rats

Zusammenfassung Intraperitonale Verabreichung von 3-Hydroxy-3-Methylglutarsäure setzt bei normalen Ratten den Serumspiegel von Cholesterin, Cholesterinestern, Esterfettsäuren und Triglyceriden signifikant herab. Bei einer cholesterinreichen Diät werden die Konzentrationen von Cholesterin und seinen Estern, bei hyperlipämischen Tieren die des Cholesterins im Serum nicht herabgesetzt. Die übrigen Lipidfraktionen verhalten sich wie im ersten Versuch.     

Tissue distribution and nucleic acid binding of chlorambuci-3H in tumor-bearing rats

Summary In tumour and normal rat tissues prolonged alkylation of DNA and RNA by chlorambucil-³H occurs over periods of 24 h. It is suggested that this may indicate the slow release of an alkylating moiety from an intracellular drugmacromolecule complex.     

The biliary excretion of [3H] lysergic acid diethylamide in Wistar and gunn rats

Summary The biliary excretion of [³H] LSD was studied in Wistar and homozygous Gunn rats. In Wistar rats approximately 46% of the given dose was recovered from bile in 2.5 h whilst in the homozygous Gunn rat 26% was recovered in the same time period. In both strains the main metabolites were glucuronides.     

3-Hydroxy-4-methoxyphenethylamine,the cardioactive constituent of a soft coral

Summary Intravenous administration to rats of the aqueous extract of the soft coralNephthea sp. caused an increase in heart rate and blood pressure. The cardioactive constituent was isolated and shown to be 3-hydroxy-4-methoxyphenethylamine.     

The biliary excretion of [3H] lysergic acid diethylamide in Wistar and Gunn rats.

The biliary excretion of [3H] LSD was studied in Wistar and homozygous Gunn rats. In Wistar rats approximately 46% of the given dose was recovered from bile in 2.5 h whilst in the homozygous Gunn rat 26% was recovered in the same time period. In both strains the main metabolites were glucuronides.     

Absorption and biotransformation of L(+)-tartaric acid in rats

Summary Oral or parenteral doses of monosodium¹⁴C-L(+)-tartrate (400 mg/kg) are rapidly excreted by rats and a proportion completely metabolized to CO₂. The oral dose was well-absorbed.     

Nicotine and ascorbic acid effects on cold-restraint ulcers in rats

Summary Rats were orally administered 1-ascorbic acid, nicotine, 1-ascorbic acid and nicotine, or distilled water for 10 days. Following this treatment they were fasted for 24 h and then restrained in a cold environment for 2h. Nicotine alone produced significantly more gastric ulcers than any other treatment. 1-Ascorbic acid increased ulceration relative to controls. The combined effects of 1-ascorbic acid and nicotine resulted in reduced ulcer incidence and severity. It appears that 1-ascorbic acid and nicotine do not act synergistically to augment stress-induced gastric ulcer. Supported by Natural Sciences and Engineering Research Council of Canada grant No. A 6312.