Search PubMedSearch

Biomedical subjects

L Halmy

Publications and source records attributed to L Halmy.

At least 19 recordsLinked to original sources

Obesity induced by kainic acid microlesion in the ventromedial hypothalamus in rats.

The neurotoxin kainic acid was injected bilaterally into the ventromedial hypothalamus of female rats in doses of 100 or 200 ng. The injections produced microlesions which led to progressive body weight gain and fat deposition in dose dependent manner. The histological examination revealed that the lesions were mainly located in the region between the ventromedial hypothalamic nuclei and the fornix.

Animals

High serum bile acid level in obesity: its decrease during and after total fasting.

Elevated serum bile acid levels were observed in overweight subjects as compared to those with an ideal weight. Fasting for 14 days resulted in a gradual decrease to the normal level of serum cholic, chenodeoxycholic and deoxycholic acid concentrations. There was no change in the serum bile acid level during a two days refeeding period. The findings suggest that, in addition to the beneficial weight reduction, normalization of bile acid homeostasis can be achieved by fasting in obesity.

Adult

Dehydroepiandrosterone concentration in adipose tissue of normal and overweight subjects.

Unconjugated dehydroepiandrosterone has been isolated from human abdominal adipose tissue and identified by double isotope derivatization and recrystallization to constant isotope ratio. Gas chromatography with electron capture detection revealed an actual dehydroepiandrosterone concentration between 0.32 to 2.82 mug/g in adipose tissue of normal and overweight subjects. The approximate dehydroepiandrosterone content of the total adipose tissue mass varied between 30 and 173 mg in subjects with severe obesity.

Adipose Tissue

Dynamic appearance of [4-14C] dehydroepiandrosterone and [7 alpha-3H] dehydroepiandrosterone sulphate metabolites in urine of normal and obese female subjects.

[4-14C]-Dehydroepiandrosterone and [7 alpha-3H]-Dehydroepiandrosterone sulphate were injected simultaneously to normal and obese female subjects. The percentage recovery of 14C and 3H radioactivies in dehydroepiandrosterone sulphate, androsterone sulphate, etiocholanolone sulphate, androsterone glucuronoside and etiocholanolone glucuronoside was determined in the day-to-day urine collections for 72 hr. Results showed a normal total 3H recovery and a poor 14C recovery in urinary conjugates of obese patients. The rate of appearance of 3H activity was not identical in the individual metabolites of normal subjects, and it was not normal in obesity. Overweight subjects exhibited an acceleration in [7 alpha-3H]-Dehydroepiandrosterone sulphate metabolism to androsterone glucuronoside. The observation regarding the rate of appearance of urinary conjugates bearing 14C isotope correlate with our previous finding in which a glandular overproduction of free dehydroepiandrosterone was found and an uptake of this steroid by the adipose tissue was suggested. Our results showed that the poor recovery of 14C radioactivity in urine of obese female subjects was not an aspecific consequence of illness.

Adult

Dehydroepiandrosterone and dehydroepiandrosterone sulfate dynamics in obesity.

Dehydroepiandrosterone (D) and dehydroepiandrosterone sulfate (DS) dynamics were studied in three obese female subjects following a single injection of [4-14-CA1D and [7 alpha-3-H]-DS tracers. Dynamic parameters were calculated simultaneously by both the urinary and blood method of compartmentalization; Estimates for the urinary secretion and production rates of D were found to be high, and those of DS varied within normal range. Calculation of the conversion factors, rho DDS and rho DSD, by the urinary method revealed a noraml extraglandular DS yields D conversion, while that for D yields DS appeared deficient in obese female subjects. Estimates of inner and outer pool distribution volumes were extremely increased for free D; in contrast to this, moderately increased inner and decreased outer pool volumes of DS were observed. The metabolic clearance rates of D were normal or decreased and those for DS were greater than normal. The blood production rates of both B and DS were higher in obese female subjects than those estimated for normal women in our previous study; These observations suggest a considerable uptake of unconjugated D by adipose tissue, an overall poor D yields DS conversion and an accelerated DS metabolism in obese female subjects.

Adult

Growth hormone and prolactin content of hyperplastic anterior pituitary of dehydroepiandrosterone treated rats.

30 days after implantation of 80 mg dehydroepiandrosterone (androst-5-en-3betaol-17-one) hyperplastic enlargement of the anterior pituitary has been observed in about 80 per cent of the female rats. There was an important increase of prolactin content, growth hormone content remained unchanged. The mentioned alterations were found to be reversible, since regression was observed after DEA treatment exceeding 30 days. In females developing no hyperplasia pituitary growth hormone contentration and content has been decreased, prolactin content remained unchanged. In male rats on identical treatment no change of pituitary weight, growth hormone and prolactin concent has been found. The results suggest that, under physiological conditions, DEA does not affect pituitary growth hormone and prolactin content, however response to pharmacological doses was different in male and female rats.

Animals