Ovarian stimulation by exogenous gonadotrophins in fetal ethanol-exposed immature rats

Adult pregnant rats were given either an ad libitum liquid diet containing 5% ethanol, a pair fed liquid diet or an ad libitum diet of rat chow and water administered throughout pregnancy and during the nursing period. The female offspring received either pregnant mare's serum gonadotrophin (PMSG) or PMSG followed by human chorionic gonadotrophin (hCG) at 30 days of age. The ovaries of fetal ethanol-exposed animals responded greater to the exogenous gonadotrophins with enhanced ovarian weights, increased numbers of ova shed, greater numbers of corpora lutea and antral follicles, and higher serum progesterone levels than in animals exposed to the control diets during gestation.     

Ovarian stimulation by exogenous gonadotrophins in fetal ethanol-exposed immature rats

Summary Adult pregnant rats were given either an ad libitum liquid diet containing 5% ethanol, a pair fed liquid diet or an ad libitum diet of rat chow and water administered throughout pregnancy and during the nursing period. The female offspring received either pregnant mare's serum gonadotrophin (PMSG) or PMSG followed by human chorionic gonadotrophin (hCG) at 30 days of age. The ovaries of fetal ethanol-exposed animals responded greater to the exogeneous gonadotrophins with enhanced ovarian weights, increased numbers of ova shed, greater numbers of corpora lutea and antral follicles, and higher serum progesterone levels than in animals exposed to the control diets during gestation.     

Effect of diet on osmotic water flow across rat colon mucosa

Summary Osmotic water flow across colon mucosa was increased in rats adapted to a high protein diet (HP) compared to rats fed a high carbohydrate diet (HC). The diet-induced change of the osmotic permeability of the colon is probably a manifestation of a regulatory mechanism controlling intestinal water absorption.Supported by the Deutsche Forschungsgemeinschaft.The technical assistance of Miss Margitta Hosser is gratefully acknowledged.     

Dietary induced increase of lactase activity in adult rats is independent of adrenals

Adult rats fed 10 days a low starch-high fat diet were either adrenalectomized or sham-operated and force-fed the same diet another 5 days; 14 h before sacrifice, some animals were force-fed a sucrose diet. Activity of lactase, sucrase and maltase was increased in adrenalectomized and sham-operated rats.     

Dietary induced increase of lactase activity in adult rats is independent of adrenals

Summary Adult rats fed 10 days a low starch-high fat diet were either adrenalectomized or sham-operated and force-fed the same diet another 5 days; 14 h before sacrifice, some animals were force-fed a sucrose diet. Activity of lactase, sucrase and maltase was increased in adrenalectomized and sham-operated rats.Supported by the National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland, USA (AM 27624).     

Effect of a restricted diet on the in vitro glucose-induced insulin release of aging rats

To study the effect of a sudden loss of body weight on the -cell function of aging rats, basal and glucose-induced insulin secretion was measured in pancreatic islets obtained from young (2-month-old), adult (12-month-old) and aging (24-month-old) rats, either fed ad libitum or fed a restricted diet (50% caloric restriction). Basal insulin secretion was similar in islets of young, adult and older rats. Glucose stimulated insulin release was significantly reduced in aging rats as compared to young animals. Animals fed a restricted diet showed a prolonged and higher secretory rate during first phase release when compared to animals fed ad libitum.     

Primary liver carcinogenesis induced by the pesticide 2-(4-tert-butylphenoxy0-1-methylethyl 2-chloroethyl sulphite (Aramite)]

Wistar rats were fed, during 56 weeks, a diet containing 5 g/kg of Aramite. At the end of the treatment, all the surviving animals show, on anatomo-pathological examination, malignant proliferation of the hepatic tissue and, in certain cases, of biliary ducts. This compound, proposed in the past as acaricide in agriculture, can thus be considered as a model substance for induction of malignant liver tumors.     

Effect of a restricted diet on the in vitro glucose-induced insulin release of aging rats.

To study the effect of a sudden loss of body weight on the beta-cell function of aging rats, basal and glucose-induced insulin secretion was measured in pancreatic islets obtained from young (2-month-old), adult (12-month-old) and aging (24-month-old) rats, either fed ad libitum or fed a restricted diet (50% caloric restriction). Basal insulin secretion was similar in islets of young, adult and older rats. Glucose stimulated insulin release was significantly reduced in aging rats as compared to young animals. Animals fed a restricted diet showed a prolonged and higher secretory rate during first phase release when compared to animals fed ad libitum.     

Chromosomal abnormalities in starved and marginally malnourished rats and in utero upon rehabilitation

The effects of starvation and marginal malnutrition (MN) on the lymphocytes of rats were evaluated by chromosomal analysis before and after rehabilitation. The effect of parental starvation or malnutrition on chromosomal aberrations in the foetus was also studied. Wistar rats, 30–35 days old, were starved for 5 days or fed a minimally restricted or a severely restricted diet for three weeks. At the end of the period of starvation or malnutrition, lymphocytes were isolated and chromosomal analysis was performed. Starved and severely restricted rats showed significantly higher mean chromosomal aberrations than the controls. These aberrations returned to a normal level when the experimental groups were rehabilitated for a month, indicating that the damage was transient. A chromosomal aberration study done on foetal cells from rehabilitated rats which had previously been starved or fed a severely restricted diet showed significantly increased values, indicating that some damage was permanent. A low number of implantations was also recorded in these experimental groups. These observations clearly indicate that young animals exposed to conditions like starvation or chronic malnutrition are prone to permanent damage of the genetic system.     

Hypolipidemic effects of garlic oil in rats fed ethanol and a high lipid diet

Summary Feeding of ethanol and a high fat-high cholesterol diet to rats markedly increased the total lipids in the liver, and cholesterol and triglyceride levels in the serum, liver and kidneys. However, when ethanol mixed with 0.5% garlic oil was fed to animals maintained on the high fat-high cholesterol diet, these lipid levels were significantly reduced to levels near to those seen in untreated control rats. Garlic oil did not reduce the serum albumin or the total proteins of liver, kidneys or serum when fed along with ethanol. Probably the garlic oil enhances the catabolism of dietary cholesterol and fatty acids.The authors acknowledge with thanks the financial assistance of the University of Maiduguri for carrying out this project.     

Hepatic phosphatidylcholine synthesis in deficiency of lysine and threonine: effect of malathion

Rats fed on a rice diet deficient in lysine and threonine showed increased activities of CDP-Choline pathway enzymes and incorporation of (methyl-3H)-choline into hepatic microsomal phosphatidylcholine, compared to rats fed on the same diet supplemented with lysine and threonine. However, the amount of microsomal phosphatidylcholine was significantly decreased in rats fed a deficient rice diet. These results suggest an enhanced phosphatidylcholine catabolism in rats fed on a rice diet deficient in lysine and threonine. Malathion administration reduced the amount of phosphatidylcholine in all the groups.     

Hepatic phosphatidylcholine synthesis in deficiency of lysine and threonine: effect of malathion

Summary Rats fed on a rice diet deficient in lysine and threonine showed increased activities of CDP-Choline pathway enzymes and incorporation of (methyl-³H)-choline into hepatic microsomal phosphatidylcholine, compared to rats fed on the same diet supplemented with lysine and threonine. However, the amount of microsomal phosphatidylcholine was significantly decreased in rats fed a deficient rice diet. These results suggest an enhanced phosphatidylcholine catabolism in rats fed on a rice diet deficient in lysine and threonine. Malathion administration reduced the amount of phosphatidylcholine in all the groups.     

Increased sensitivity to pentobarbital in rats fed a diet lacking flavonoids.

Pentobarbital-sensitivity is highly increased in rats fed a diet lacking flavonoids; sleeping time was found to be increased by 42 and 30% as compared with rats fed a normal diet. These studies confirm our previous statement according to which for the rat, benzopyrones are vitamins.     

Suppression of the immune response by drugs interfering with the metabolism of serotonin

Summary The work was based on the assumption that neurohumoral control of the immune response, particularly in stressed animals, involves central serotoninergic mechanisms. Rats immunized with sheep erythrocytes were stressed by repeated restraints and/or treated with a precursor of serotonin (5-hydroxytryptophan, 5-HTP) or with an inhibitor of serotonin synthesis (parachlorophenylalanine, PCPA). As expected, repeated stresses reduced the plaque-forming cell (PFC) response. Treatment with 5-HTP also reduced the PFC response, and potentiated the immunosuppressive effect of stress. This was accompanied by increased metabolism of serotonin in the brain, as indicated by increased concentration of its metabolite, 5-hydroxyindoleacetic acid (5-HIAA), in cerebral tissue. Treatment with PCPA also suppressed the PFC response, but this suppression was accompanied by decreased levels of brain serotonin and of 5-HIAA. Plasma corticosterone levels were elevated in rats treated with PCPA. It seems that putative central effects of PCPA on serotoninergic regulation of the immune response were outweighed by its effects on corticosterone secretion and/or on lymphoid cells.     

Suppression of the immune response by drugs interfering with the metabolism of serotonin

The work was based on the assumption that neurohumoral control of the immune response, particularly in stressed animals, involves central serotoninergic mechanisms. Rats immunized with sheep erythrocytes were stressed by repeated restraints and/or treated with a precursor of serotonin (5-hydroxytryptophan, 5-HTP) or with an inhibitor of serotonin synthesis (parachlorophenylalanine, PCPA). As expected, repeated stresses reduced the plaque-forming cell (PFC) response. Treatment with 5-HTP also reduced the PFC response, and potentiated the immunosuppressive effect of stress. This was accompanied by increased metabolism of serotonin in the brain, as indicated by increased concentration of its metabolite, 5-hydroxyindoleacetic acid (5-HIAA), in cerebral tissue. Treatment with PCPA also suppressed the PFC response, but this suppression was accompanied by decreased levels of brain serotonin and of 5-HIAA. Plasma corticosterone levels were elevated in rats treated with PCPA. It seems that putative central effects of PCPA on serotoninergic regulation of the immune response were outweighed by its effects on corticosterone secretion and/or on lymphoid cells.     

Epithelial localization of pyruvate kinase L (ATP pyruvate phosphotransferase EC 2.7.1.40) in rat liver]

Using three methods: histoenzymatic and immunoenzymatic, stained with tetrazolium salt, and immunofluorescence, we have localized PK "L" in hepatocytes. This localization in the cytoplasm of the cells differs widely in intensity with diet or hormone administration. Maximal with animals fed on high carbohydrate diet, still elevated with a subsequent insulin administration, it decreases with a normal diet to become weaker in animals, which have fasted for 48 hrs.     

Effect of the type of diet on the distribution of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase in rat small intestine

Summary The jejunoileal gradient for the HMG-CoA reductase activity in the microsomal fraction of the epithelial cells of the small intestine of rats given commercial pellets was reserved within a few days after changing the ration to a semipurified diet. The response of the reductase was essentially the same in villus and crypt cells.     

Changes in serum proteins and in major liver constituents following carbon tetrachloride and a high-fat choline-free diet in rats.

Both carbon tetrachloride and a high-fat, low-protein choline-free diet cause hepatomegaly in rats due to an accumulation of both lipids and proteins with a concomitant increase in deoxyribonucleic acid content. CCl4 causes a decline in hepatic glycogen. Serum albumin level is decreased in CCl4-treated rats and increased in those fed the experimental diet.     

A synergistic interaction between the teratogenic effect of trypan blue and dietary deficiency in the rat.

There was an increased incidence, compared to controls, of exencephaly and microphthalmia in the offspring of rats fed a vitamin D deficient diet and injected with trypan blue on day 9 of gestation. Oral vitamin D did not reverse the effect.     

Physiological mechanism by which acetyl CoA carboxylase is regulated

Compared with rats fed a normal diet, the activity of the protein inhibitor of acetyl CoA carboxylase in rat liver doubled after 48 h of fasting. Conversely, acetyl CoA carboxylase activity was diminished by nearly one half. In animals fasted and then subsequently refed a fat free diet, acetyl CoA carboxylase activity was elevated by nearly 9-fold, with a concomitant decrease in the activity of the protein inhibitor by about 9-fold as compared to fasted rats. Hence it appears that the regulatory protein inhibitor for acetyl CoA carboxylase is of physiological significance for fatty acid biosynthesis.