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Biomedical subjects

L Srivastava

Publications and source records attributed to L Srivastava.

At least 55 records · Page 3Linked to original sources
PubMed1981

Patterns of spontaneous LH release in normo- and hyperprolactinaemic women.

Hyperprolactinaemia may be associated with functional amenorrhoea. In order to evaluate the possible role of abnormal spontaneous LH secretion in hyperprolactinaemic amenorrhoeic women, plasma LH was measured at 15 min intervals for 300 min in 12 normal women during the early follicular phase of the menstrual cycle and compared to that observed in 11 hyperprolactinaemic amenorrhoeic subjects. Mean plasma prolactin was 9.1 +/- 3.6 ng/ml (X +/- SEM) in the euprolactinaemic and 168 +/- 32 ng/ml in the hyperprolactinaemic group. Sex steroids including oestrone, oestradiol, progesterone and 17-hydroxyprogesterone were similar in the 2 groups. Mean plasma LH levels over the 300 min sampling period were 9.4 +/- 1.6 mIU/ml in the normal subjects and 7.5 +/- 1.0 mIU/ml in the hyperprolactinaemic patients (P greater than 0.10). Every normal woman exhibited at least one LH spike in excess of 10 mIU/ml. Five hyperprolactinaemic patients failed to exhibit any LH spikes above 10 mIU/ml (P less than 0.02 compared to controls). Thus, hyperprolactinaemia was associated with an absence of LH spike activity in 45% of patients studied and this abnormality may play an aetiologic role in the hypogonadism observed in these subjects; in those hyperprolactinaemic subjects with pulsatile LH secretion, however, other explanations for their amenorrhoea should be considered.

Adolescent↗
PubMed1980

The occurrence of hyperaldosteronism in infants with congestive heart failure.

Serum aldosterone and plasma renin were measured in 20 normal infants and 15 infants with congestive cardiac failure. Serum aldosterone was significantly increased (151 +/- 38 ng/dl mean +/- standard error of the mean) in patients before treatment when compared with aldosterone in normal infants (29 +/- 7 ng/dl). Increasing serum aldosterone was related to increasing plasma renin. The response to furosemide appeared to be inversely related to serum aldosterone concentrations. In four infants, administration of an aldosterone antagonist (spironolactone) resulted in improved diuresis and decreased serum aldosterone. Hyperaldosteronism is an important factor contributing to fluid and sodium retention in infants with heart failure.

Aldosterone↗
PubMed1980

Differential lipemic and proteinemic response to oral ethinyl estradiol and parenteral estradiol cypionate.

Oral synthetic estrogen administration to normal women has been shown to result in both a lipemic and a proteinemic response. To determine whether parenteral estrogen administration would have similar results, the effects of intramuscular depo-estradiol cypionate on serum lipids and ceruloplasmin were examined. The oral and parenteral estrogens chosen for this study are frequently used therapeutically and varying doses in the range of those commonly employed clinically were given to the experimental subjects. Following oral ethinyl estradiol (20, 50, and 100 micrograms every 12 hr) comparable and significant increases in triglyceride (73 +/- 6 to 128 +/- 10 mg/dl, p < .001), ceruloplasmin (87 +/- 4 to 188 +/- 11 mg/dl, p < .001), and HDL-cholesterol (60 +/- 2 to 74 +/- 3 mg/dl, p < .001) were observed. In contrast, despite substantial increases in serum estrogens, parenteral estrogen administration (depo-estradiol cypionate, 5 and 10 mg) failed to result in alterations in any of the measured parameters. Thus, the route and/or type of estrogen administered may determine the proteinemic and lipemic effects of estrogen in man.

Administration, Oral↗
PubMed1977

Insulin, obesity, and triglyceride interrelationships in sixteen children with familial hypertriglyceridemia.

Sixteen children with familial hypertriglyceridemia were studied to determine whether there were any distinctive insulintriglycerid-obesity relationships in pediatric familial hypertriglyceridemia. Eleven of 16 children had calculated fat mass greater than the 97th percentile for age, height, and sex. When compared with 16 normal control subjects matched for degree of obesity immunoreactive insulin and glucose response during oral glucose tolerance was similar for normal and hypertriglyceridemic children. By either simple correlation or multiple regression analysis, plasma, triglycerides did not correlate significantly with measurements of insulin or obesity in hypertriglyceridemic or normal children. Within the limits of a small sample size, and in the presence of obesity, insulin does not appear to play a predominant role in the genesis of hypertriglyceridemia in children with familial hypertriglyceridemia. With a small mean weight loss of 1.8 kg and adherence to a diet with 20% of calories as protein, 40% each as fat and carbohydrate, polyunsaturate to saturate ratio of 1.5:1, mean plasma triglycerides were reduced from 238 to 140 mg/100 ml in the 11 obese children with familial hypertriglyceridemia (P less than 0.02). Speculation In spite of the complicating role of obesity, adolescence, and the small sample size, it is interesting to note that the correlation coefficients between triglyceride and insulin/glucose area (0.36), and insulin area (0.30), although not significant (P less than 0.1), were considerably higher in hypertriglyceridemic children than in normal subjects in whom comparable correlation coefficients were 0.08 and 0.08. This infers that the potential role of insulin in triglyceride metabolism in children with familial hypertriglyceridemia might be discerned with longitudinal follow-up into adulthood.

Adolescent↗
PubMed1976

Dissociation between LH release and pituitary cyclic nucleotide accumulation in response to synthetic LH-releasing hormone in vivo.

In order to clarify the role of cyclic nucleotides in the mediation of LH-releasing hormone (LH-RH) action on LH release, the effect of LH-RH on LH release and pituitary cyclic AMP and cyclic GMP accumulation was studied in vivo. Pituitary cyclic AMP levels were increased 10 min after the intraveneous injection of 2 mg dibutyryl cyclic AMP (db-cyclic AMP) or 25 mg aminophylline. However, serum LH levels were not altered at 10, 30 or 60 min after the administration of either agent. Synthetic LH-RH (100 ng/rat) increased serum LH levels as measured 10 min after injection, but no effect on either pituitary cyclic AMP or cyclic GMP was seen 1, 5 or 10 min after LH-RH administration. These in vivo results are contradictory to the second messenger hypothesis for either cyclic AMP or cyclic GMP in the mediation of LH-RH-induced LH released and suggest that further work must be done in order to confirm or reject this hypothesis.

Aminophylline↗
PubMed1975

The in-vitro and in-vito effects of diethylstilbestrol on testicular synthesis of testosterone.

The effect of diethylstilbestrol (DES) on the percent conversion of a 14C-progesterone (14C-P) substrate to 14C-testosterone (14C-T) when added to incubates fo rat testicular homogenates has been measured. Similarly the effect of DES administered parenterally to intact adult rats at 9 dose regimens on such conversion has been evaluated. In addition, in the latter group serum luteinizing hormone (LH) levels were assessed simultaneously. DES added in-vitro significantly reduced T formation at every level. Only the large parenteral dose of DES affected T synthesis after 24 hours, while every parenteral dose significantly reduced T synthesis with 4 and 8 day regimens. Mean serum LH levels failed to reflect a significant decrease at the 1 and 4 day dose level, but did decrease significantly in 2 of 3 groups on the 8 day regimen. These results suggest that there is a direct effect of DES at a testicular level inhibiting T synthesis not associated with a simultaneous drop in mean serum LH levels. A measurable decrease in LH concentration does occur with continued treatment.

Animals↗
PubMed1975

Plasma renin activity in juvenile diabetes mellitus and effect of diazoxide.

Low plasma renin activity (PRA) has been reported in patients with long-term diabetes mellitus complicated by hypertension and nephropathy. We have assayed PRA in twelve normal subjects and in eight age- and sex-matched juvenile diabetics of greater than twelve years' duration without hypertension and nephropathy under control conditions and following stimulation with diazoxide. During control conditions PRA did not decrease with time in the diabetics as it did in the normals. Following diazoxide infusion, PRA increased in both groups, and although the levels were often higher in diabetics than in normals, the mean differences were not statistically significant. The findings are consistent with the suggestion that PRA is normal or possibly elevated in clinically uncomplicated insulin-dependent diabetes mellitus and decreases with establishment of hypertension and nephropathy.

Adult↗