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Plasma FSH concentrations in rats have been determined by radioimmunoassay under a variety of experimental conditions to see whether any evidence could be obtained of an acute divergence in LH and FSH secretion rates which would support the idea of separate, specific hypothalamic releasing factors for these two hormones. During the normal ovarian cycle and after the administration of progesterone to female rats on the morning of the day of pro-oestrus increased secretion of both LH and FSH began simultaneously but FSH concentrations were later maintained or increased slightly while LHING EARLY PREGNANCY FSH concentrations were higher than at the corresponding stage of the cycle at a time when LH concentrations had been shown to be lower. Progesterone injected at the dioestrous stage of the cycle reduced both LH and FSH concentrations though the effect on LH was more marked. After ovariectomy at any stage of the oestrous cycle or on day 4 of pregnancy there was a rapid and significant increase in plasma FSH concentration which was quite different from the delayed increase in LH concentration observed in these animals. In contrast, the early increase in FSH concentration in male rats after castration was less than the increase in LH concentration. The final FSH concentration in castrated males was only about four times the basal level in contrast to the 10- to 15-fold increase in LH in males and both LH and FSH in females. Anovulatory adult females that had received 1-25 mg of testosterone propionate on day 4 of postnatal life showed the rapid and sustained increase in plasma FSH after ovariectomy that was seen in normal females. None of these results strongly support the idea that separate and specific hypothalamic releasing factors for LH or FSH are secreted in the rat although the differences in the early response to gonadectomy could be explained on this basis.

A 1.6-yr-old Hispanic boy with sparse hair, muscle weakness, severe growth retardation, and rickets was found to have hypocalcemia, secondary hyperparathyroidism, and high circulating 1,25-dihydroxyvitamin D [1,25-(OH)2D] levels. One year of treatment with a high dose of 1,25-(OH)2D3 (20 micrograms, orally, daily) resulted in marked subjective and radiological improvement; there was a parallel improvement in serum calcium, phosphorus, PTH, alkaline phosphatase, and osteocalcin concentrations. Soluble extracts from cultured skin fibroblasts did not bind [3H]1,25-(OH)2D3 using standard methods. To evaluate the possibility of receptors with abnormally low affinity, we tested for binding with [3H]1,25-(OH)2D3 concentrations higher than those usually used. In one experiment, there was a suggestion of low affinity binding. Hormone receptors with abnormally low affinity for 1,25-(OH)2D may explain this patients resistance to 1,25-(OH)2D. Therapy to maintain extremely high serum 1,25-(OH)2D3 concentrations markedly improved mineral homoeostasis, but did not affect the hair disorder.

Percutaneous transluminal renal angioplasty (PTRA) has been infrequently used in the treatment of children with hypertension due to renal artery stenosis. We report our results in five patients aged 4 to 22 years with hypertension diagnosed at ages 1 1/2 to 10 years. Four of the five patients had been on antihypertensive medication prior to angioplasty. Four had fibromuscular disease and one had probable Takajasu's arteritis; two had solitary kidneys. Following angioplasty, a prompt decrease in blood pressure was observed in all patients. Further, four of five patients after PTRA were normotensive without antihypertensive medications, and in all PRA declined. PTRA can be a safe and effective alternative to surgical treatment in the management of renovascular hypertension in childhood. We suggest that PTRA should be the first procedure attempted to correct renovascular hypertension in children.

A male infant with partial duplication of the long arm of chromosome 11 (11q22----qter) is described with a hitherto unreported translocation. In most cases 11q trisomy is associated with 11q/22q translocation and a 3:1 meiotic disjunction with 47 chromosomes. In a few cases the 11q translocation is associated with a partial deletion of other autosomes and a total of 46 chromosomes. In the present case, translocation to 9p is involved and no apparent deletion of 9p was noted, providing an opportunity to delineate the phenotypic features due to duplication of 11q. A comparison is made between the findings of partial 11q trisomy and 11q/22q translocation.

The response of the adrenal glomerulosa to renin stimulation was determined in 10 patients with dexamethasone-suppressible hyperaldosteronism. The patients were treated continuously with 2 mg/day dexamethasone (DEX) and were studied on a regular sodium diet (87 meq/m2 . day) and on a 10 meq/day sodium diet. With DEX treatment all patients showed a prompt suppression of adrenal fasciculata function as evidenced by suppression of serum cortisol, corticosterone, desoxycorticosterone, and urinary 18-OH-desoxycorticosterone. The complete suppression of urinary pH 1 aldosterone (aldo) by DEX, unique to this disorder, was paralleled by a prompt suppression of urinary 18-OH-corticosterone. With continued DEX administration, plasma renin activity rose to the normal or supranormal range. Dietary sodium restriction resulted in a further rise in plasma renin activity and a rise in urinary pH 1 aldo and 18-OH-corticosterone. We conclude that in DEX-suppressible hyperpaldosteronism, although ACTH appears to be the primary stimulus for aldo secretion in the untreated state, when ACTH is suppressed, the adrenal glomerulosa responds normally to the stimulation of renin-angiotensin II.

A syndrome of low renin hypertension in childhood with apparent mineralocorticoid excess associated with a defect in the peripheral metabolism of cortisol has been described previously in 2 patients. In these patients, decreased secretion rates of glucocorticoids, mineralocorticoids, and sex steroids have been demonstrated. In a 10(10/12)-yr-old girl with this disorder, continuous iv administration of hydrocortisone in doses of 5, 10, 15, and 20 mg/day resulted in an increase in blood pressure and a decrease in serum potassium concentration. The addition of spironolactone during the continued administration of 20 mg/day hydrocortisone did not result in a decrease in blood pressure. Withdrawal of hydrocortisone and continued administration of spironolactone alone resulted in a decrease in blood pressure, a rise in serum potassium concentration, and a fall in serum sodium concentrations. These studies suggest that an abnormality in cortisol action or metabolism causing cortisol to behave as a potent mineralocorticoid may account for this syndrome of apparent mineralocorticoid excess.