1. Rats were fed on diets enriched with starch, sucrose, corn oil or beef tallow for 3 weeks and the activities of various enzymes in the liver were measured. 2. The mitochondrial glycerol phosphate acyltransferase activity was lower in rats fed on the starch diet than on the two high-fat diets. 3. The non-microsomal (presumably peroxisomal) dihydroxyacetone phosphate acyltransferase activity was higher in rats fed on the starch diet and corn-oil diets than in those fed on the sucrose and beef-tallow diets. Urate oxidase activity was higher in rats fed on the starch diet than in the three other groups. There were no significant differences in the activity of acyl-CoA oxidase among the groups. 4. The activity of soluble phosphatidate phosphohydrolase was not significantly different among the dietary groups. There were increases of 3.3--4.3-fold in this activity in the dietary groups 6h after injection of corticotropin. The equivalent increases for the mitochondrial glycerol phosphate acyltransferase were 1.4--1.6 fold. 5. The corticosterone responses to the corticotropin injection were not significantly different between dietary groups. However, the corticosterone response of the rats fed on the two high-fat diets was prolonged when the rats were given an acute load of fructose [Brindley, Cooling, Glenny, Burditt & McKechnie (1981) Biochem. J. 200. 275--283]. 6. Rats fed on the high-fat diets had higher concentrations of circulating cholesterol than those fed on the starch and sucrose diets. Serum triacylglycerol concentrations were lower in the rats fed on the starch diet than in the three other groups. 7. The results are discussed in terms of the relationship between diet, hormonal balance and hepatic glycerolipid metabolism.

Adrenocorticotropic Hormone↗

PubMed1981

The activities of lipoprotein lipase and of enzymes involved in triacylglycerol synthesis in rat adipose tissue. Effects of starvation, dietary modification and of corticotropin injection.

1. The effects of dietary modification, including starvation, and of corticotropin injection on the activities of acyl-CoA synthetase, glycerol phosphate acyltransferase, dihydroxyacetone phosphate acyltransferase, phosphatidate phosphohydrolase, diacylglycerol acyltransferase and lipoprotein lipase were measured in adipose tissue. 2. Lipoprotein lipase activities in heart were increased and those in adipose tissue were decreased when rats were fed on diets enriched with corn oil or beef tallow rather than with sucrose or starch. The lipoprotein lipase activity was lower in the adipose tissue of rats fed on the sucrose rather than on the starch diet. 3. Rats fed on the beef tallow diet had slightly higher activities of the total glycerol phosphate acyltransferase in adipose tissue than did rats fed on the sucrose or starch diet. The diacylglycerol acyltransferase and the mitochondrial glycerol phosphate acyltransferase activities were higher for the rats fed on the tallow diet than for those fed on the corn-oil diet. 4. Starvation significantly decreased the activities of lipoprotein lipase (after 24 and 48 h), acyl-CoA synthetase (after 24 h) and of the mitochondrial glycerol phosphate acyltransferase and the N-ethylmaleimide-insensitive dihydroxyacetone phosphate acyltransferase (after 48 h) in adipose tissue. The activities of the microsomal glycerol phosphate acyltransferase, diacylglycerol acyltransferase and the soluble phosphatidate phosphohydrolase were not significantly changed after 24 or 48 h of starvation. 5. The activities of lipoprotein lipase and phosphatidate phosphohydrolase in adipose tissue were decreased 15 min after corticotropin was injected into rats during November to December. No statistically significant differences were found when these experiments were performed during March to September. These differences may be related to the seasonal variation in acute lipolytic responses. 6. These results are discussed in relation to the control of triacylglycerol synthesis and lipoprotein metabolism.

Adipose Tissue↗

PubMed1981

Stimulation of the activities of phosphatidate phosphohydrolase and tyrosine aminotransferase in rat hepatocytes by glucocorticoids.

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Animals↗

PubMed1977

The effects of acute ethanol feeding and of chronic benfluorex administration on the activities of some enzymes of glycerolipid synthesis in rat liver and adipose tissue.

Rats were treated for 5 days with benfluorex [1-(3-trifluoromethylphenyl)-2-[N-(2-benzoyloxyethyl)amino]propane] or with suspending medium (controls). They were then intubated with an acute intoxicating dose of ethanol or with glucose of equivalent energy content. Treatment of the control rats with ethanol specifically increases the hepatic activity of the soluble phosphatidate phosphohydrolase by about 5-fold in 6 h. The equivalent increase for the benfluorex-treated rats were about 2-fold. The results are discussed in relation to the effects of ethanol and benfluorex on glycerolipid synthesis.

Adipose Tissue↗

PubMed1974

Identification of a ventral scent marking pheromone in the male Mongolian gerbil (Meriones unguiculatus).

Sebum from the ventral scent marking gland of the male Mongolian gerbil was fractionated and tested for its ability to elicit behavioral response in a conditioning task and in a stimulus preference situation. The active fraction was identified as phenylacetic acid; both it and a synthetic sample elicited the same behavioral response. Phenylacetic acid appears to be a major pheromone of the male Mongolian gerbil.

Animals↗

PubMed1973

Fresh autologous blood transfusions with extracorporeal circulation.

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Adolescent↗

PubMedDate not supplied

The myelotoxicity of carboplatin is influenced by the time of its administration.

Previous studies have demonstrated that there are circadian rhythms in susceptibility to a range of commonly used cytotoxic drugs. In this study we have compared the pharmacokinetics and myelotoxicity of carboplatin administered at 18.00 and 06.00 in random order in patients with advanced ovarian carcinoma. Carboplatin treatment at 06.00 is associated with significantly greater thrombocytopenia than at 18.00 (platelet nadir 95,000 versus 180,000, p less than 0.05). There was no pharmacokinetic difference in the patients' handling of ultrafilterable platinum therefore it is possible that there is an intrinsic rhythm of susceptibility of bone marrow to carboplatin.

Blood Cell Count↗

PubMedDate not supplied

Laboratory studies in cross-species lung transplantation.

The lack of sufficient suitable human donor lungs for the many patients requiring pulmonary transplantation as life-saving therapy for end-stage lung diseases has generated extensive interest in cross-species lung transplantation. Ethical concerns and those of animal rights advocates have prompted studies of nonprimate species as potential solid organ donors for humans. This paper provides an overview of some of the laboratory studies of cross-species pulmonary transplantation performed over the past 20 years and focuses, in particular, on more recent work (from our laboratory and others) in the area of porcine-to-primate pulmonary xenotransplantation.

Animals↗

PubMedDate not supplied

Platelet behaviour and haemostatic variables in type 1 (insulin-dependent) diabetic patients with and without albuminuria.

Abnormalities of haemostasis have been implicated in the development of both large and small vessel disease in diabetes. Platelet behaviour and coagulation factors were studied in 28 non-diabetic control subjects and 81 Type 1 diabetic patients with different degrees of albuminuria. Twenty-four (30%) patients had macro- or micro-albuminuria. These patients had elevated levels of beta-thromboglobulin compared with normo-albuminuric patients and control subjects (macro-albuminuric 113 (range 60-314), micro-albuminuric 88 (50-220), normo-albuminuric 55 (13-273), control 52 (18-210) micrograms l-1, p less than 0.001). Similar results were found for platelet factor 4 (macro-albuminuric 57 (9-350), micro-albuminuric 78 (12-205), normo-albuminuric 10 (2-135), control 9 (3-95) micrograms l-1, p less than 0.001). There were decreased beta-thromboglobulin:platelet factor 4 ratios in the albuminuric patients compared with control subjects and normo-albuminuric patients (p less than 0.001). There is abnormal platelet activity in Type 1 diabetic patients with elevated albumin excretion rates.

Adult↗

PubMedDate not supplied

Effects of dietary N-3 and saturated fats on growth rates of the human colonic cancer cell lines SW-620 and LS 174T in vivo in relation to tissue and plasma lipids.

Ninety nude mice were inoculated subcutaneously with 1 x 10(7) cells of the human colonic cancer cell lines, SW-620 and LS174T. Tumour growth was assessed weekly for three weeks whilst the animals were receiving one of three diets: control (4.6% fat), coconut (20% fat, saturated fatty acids) and Maxepa (20% fat; n-3 fatty acids). At the end of the study SW-620 tumour weights (mean +/- SD, gm) were: control = 0.38 +/- 0.22, coconut = 0.43 +/- 0.31, Maxepa 0.20 +/- 0.16; the LS174T tumour weights were control = 1.33 +/- 1.27, coconut = 0.47 +/- 0.74, Maxepa = 0.38 +/- 0.56 (p less than 0.001, analysis of covariance). The Maxepa diet produced significant retardation in tumour growth (p less than 0.001). This was associated with reduced levels of linoleic acid and arachidonic acid in adipose tissue and tumour lipids with incorporation of n-3 fatty acids (all p less than 0.01 at least, analysis of variance). Moreover, the Maxepa diet produced significant reductions of plasma cholesterol, phospholipids and triglycerides (all p less than 0.01).

Adipose Tissue↗