Asscorbic acid portects against male infertility in a teleost fish

An animal unable to synthesize ascorbic acid uniquely minicks human and non-human primates. Therefore, in this study we used the rainbow trout, a teleost fish, as the model animal to study the importance of dietary ascorbic acid on the fertilizing ability of sperm. A high concentration of ascorbic acid in semen plays a key role in maintaining the genetic integrity of sperm cells, by preventing oxidative damage to sperm DNA. This study will show that the concentration of asorbic acid in seminal plasma refelcts the dietary fed either an ascorbate-free diet (from 4.74±0.9 to 0.16±0.08 g ml^–1) or an ascorbate-rich diet (from 37.9±4.7 to 17.7± 3.2 g ml^–1) during the sperimnation season. The relationship between ascrobate status and fertility was studied in six groups of fish fed graded levels of ascorbic acid, which sperimated over a 150-day-period. Sperm from individual males was used to fertilize several batches of eggs. When the seminal plasma ascorbate concentration decreased to 7.3 g ml^–1 a significant decrease of fertilization rate and the hatching rate of embryos resulted. This is the first evidence that dietary ascorbate level directly affected sperm quality and influenced male fertility in a scruvy-prone vertebrate.     

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.     

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.     

The effect of a low protein diet on the adipocytes of rat perigenital fat

Summary Weanling rats were fed a low protein diet for 6 weeks and their weights were 50% less than controls. There were significantly fewer adipocytes per g adipose tissue, but estimates of the number of adipocytes per rat indicated that the diet had much less effect on adipocyte number than on b.wt.     

Effect of substrates on the mechanical performance of rhesus monkey papillary muscle

Summary This study examines the effect of different substrates on mechanical performance of excised papillary muscles from rhesus monkeys which had been divided into a control group and an experimental group fed a high fat diet for 5 months prior to sacrifice. The results show that performance is affected by available substrate for both groups. The performance of the experimental group was depressed relative to control with the short chain fatty acid, butyrate (C4), producing a monotonically decreasing force-frequency response. Relative to other mammals, isolated rhesus papillary muscles exhibited a protracted treppe which was sensitive to -adrenergic blockade with propranolol.Acknowledgments. I would like to thank Dr R.M. Larson, Dr R.L. McCann and Dr O.F. Hagan for making available the papillary muscles used in this study. Support for this work was provided in part by a grant from the Walker P. Inman Fund and grants from the NIH HL 17391 and HL 15448.     

Inhibitory effect of fasting on the glucagon-induced increase of liver phosphorylase A activity in rats

Summary The increase of liver phosphorylase A activity observed 1, 2 and 3 min after i.v. administration of 0.1 g kg^–1 glucagon to fed rats was found to be completely absent in 24 h fasted animals, although there is even an exaggerated liver cAMP response to glucagon after fasting.Acknowledgments. We would like to thank Mrs M. Fritzová and Mr F. Kovai for expert technical assistance.     

Effect of tea consumption on the levels ofα-ketoglutarate and pyruvate dehydrogenase in rat brain

Summary Administration of tea to rats fed on a normal diet results in a marked drop in brain levels of total thiamine as well as of -ketoglutarate and pyruvate dehydrogenase activities. The patterns of decrease in both enzyme activities are similar to that of total thiamine content; they drop to about 65% of the control at 14–20 weeks after continuous consumption of tea.Supported by a grant from the International Foundation for Science (IFS), Sweden.     

Cholesterol feeding to rats does not modulate the expression of binding sites for HDL on liver membranes

Summary The binding of HDL, Apo-E-free, was studied in rats fed a cholesterol rich diet for 2, 4 and 7 days. Plasma cholesterol increased up to 16-fold (from 55 to 900 mg/dl); liver cholesterol was also raised, from 0.5 to 16 mg/g of tissue. The HDL binding to membrane preparations was not affected while the binding of VLDL was reduced to about 50% of the controls. These data show, therefore, that liver binding sites for HDL are refractory to regulation by dietary cholesterol.     

Quantitative Versuche zur Krebserzeugung mit 4-Dimethylamino-stilben an Ratten

Summary Quantitative experiments in rats fed with 4-dimethylaminostilbene proved that the induction of ear-duct cancer is an irreversible summation action, similar to the production of hepatomas with 4-dimethylaminoazobenzene.

---

---

Die Arbeiten wurden durch die Deutsche Forschungsgemeinschaft ermöglicht.     

The effect of dietary fibre on85Sr and47Ca absorption in infant rats

Summary The retention of bone-seeking radioisotopes⁸⁵Sr and⁴⁷Ca was about 20% lower in the femur of 6-day-old infant rats artificially fed on milk, milk supplemented with calcium and phosphorus, and milk supplemented with strontium when 6% cellulose type dietary fibre was added to the diet.Acknowledgments. This work was supported by a research grant from the Scientific Research Council of the Socialist Republic of Croatia. The authors wish to thank Mrs M. Buben, E. Herak, and K. Pribi for their technical assistance.     

Variation of glutamate decarboxylase activity andγ-amino butyric acid content of wheat embryos during ripening of seeds

Summary GAD activity and -ABA content of wheat embryos at 7 ripening stages were verified with the aim of studying the metabolic activity of embryo during dehydration and quiescence of caryopsis. Data showed that in the early stage of ripening GAD activity is very low, increases rapidly at dough-stage, remaining constant up to waxystage, and decreases in the last fully-ripe embryos. -ABA content appears to be roughly parallel to the variations of GAD activity.This work was supported by a grant from the Consiglio Nazionale delle Ricerche.     

Decreased incidence of renal cell carcinoma in rats with one kidney ingesting N-4-(4′-fluorobiphenyl) acetamide

Summary Buffalo strain male rats, 12 weeks of age, ingesting 0.04% N-4-(4-fluorobiphenyl)acetamide in a semisynthetic diet with both kidneys intact were more susceptible to the development of hyperplasia and carcinomas of the kidney than were rats with a uninephrectomy.     

Plasma and hepatic antioxidant control and vitamin A nutritional status

Twenty-seven rats were divided into three groups and fed on diets containing 0.3, 6 or 60 RE (retinol equivalent) retinyl palmitate/g food. After 7 weeks, hepatic vitamin A uptake was found to be more efficient in vitamin A-deficient rats than in rats given adequate vitamin A. We showed that during the metabolic adaptation of the animals to the level of vitamin A in the diet, extensive modifications occur in the antioxidant defences of the organism. In parallel with the increase in the level of vitamin A, the decrease in the level of -tocopherol in the plasma can bring about a greater susceptibility of the lipoproteins to oxidative stress. Similarly, the decrease in the hepatic -tocopherol level and in glutathione peroxidase activity leads to the weakening of the liver's antioxidant defences.     

Inhibition of steroidogenic activity in the adrenal cortex of rats fed benzene hexachloride (hexachlorocyclohexane)

Summary Feeding various dosages of benzene hexachloride (100, 250, 750 and 1500 ppm) in the diet to weanling male albino rats for 90 days resulted in marked hypertrophy of the adrenals with large, vacuolated cells in the cortex at 750 and 1500 ppm. Accumulation of cholesterol-positive lipids and marked reduction in the activities of steroidogenic enzymes such as ⁵ 3 HSDH, 11 HSDH, G-6-PDH and SDH were seen using histochemical methods in the adrenal cortex of rats fed 750 and 1500 ppm. The results are suggestive of steroidogenic inhibition at 750 and 1500 ppm of dietary BHC while 100 and 250 ppm did not produce any discernible changes in the adrenal cortex.Acknowledgments. The authors thank Dr Muralidhara, H.P. Ramesh and K. Nanjundiah for their help and Prof. H.B. Devaraj Sarkar, Department of Zoology, University of Mysore, for providing us facilities for histochemical work. We are grateful to Sri C.P. Natarajan, for his keen interest in this investigation.     

Darstellung von Derivaten des 6-Chlor-17β-acetoxy-Δ 5-androsten-7-on

Summary 6-Chloro-17-acetoxy-5-androsten-7-one and some of its derivatives have been prepared from ⁵-steroids by a synthesis involving elimination of the substituent from position 3, introduction of a 7-keto group by allyloxidation and chlorination of the resulting compound with sulphuryl chloride.     

The participation of kinins in the pathogenesis of early disturbances in the skin capillary permeability in localβ-ray irradiation

, - Sr⁹⁰ + Y⁹⁰, , . - () . , , - .     

Mass spectrometric determination of the amino acid sequence in cystine- and cysteine-containing peptides

, - , , S-- S- .     

Steroidal effect in the resistance offered by wheat varieties toTribolium castaneum (Herbst)

Summary The steroids present in the resistant, susceptible and intermediate wheat varieties toTribolium castaneum (Herbst) were estimated quantitatively; -sitosterol shows significant differences in these varieties. The contents of -sitosterol in 4 varieties of wheat is hence correlated to the resistance of the varieties to the flour beetle.The authors are thankful to the Department of Zoology, University of Rajasthan, Jaipur, India, for providing necessary facilities. Our sincere thanks are due to Dr S.M. Gandhi, Wheat Specialist, Government Agricultural Experiment Station, Durgapura, Jaipur, India, for providing us with the wheat varieties.     

A study of the mechanism of polymyxin M inactivation

.I.NH₄OH , N N - - ,-. , .     

A study of the mechanism of lowering the sensitivity of smooth muscle to noradrenalin with sympathetic hyperinnervation

, , , , . . , .