Myeloid progenitors from the bone marrow of patients with vitamin D resistant rickets (type II) fail to respond to 1,25(OH)2D3

The active metabolite of vitamin D, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), has been shown to enhance the growth of human granulocyte/macrophage haemopoietic progenitors in vitro and to induce these cells to differentiate along the monocyte/macrophage pathway. In order to evaluate the relationship between specific receptors for 1,25(OH)2D3 and the role of 1,25(OH2D3 in the regulation of haemopoietic cell differentiation, we examined the effect of haemopoietic cell differentiation, we examined the effect of 1,25(OH)2D3 on the in vitro growth and differentiation patterns of marrow myeloid progenitor cells from two patients with 1,25(OH)2D3 resistant rickets, resulting from defective receptors to vitamin D. A significant rise in the frequency of myeloid colonies in control marrow cell cultures was induced by 2 X 10(-9) to 2 X 10(-7)M 1,25(OH)2D3. This rise reached a plateau at 2 X 10(-9)_2 X 10(-8) M 1,25(OH)2D3, resulting in a maximal 54 +/- 9% increase in colony numbers. In contrast, no stimulatory effect could be detected when 1,25(OH)2D3 was added to cultured marrow cells from the patients with 1,25(OH)2D3 resistance. Analysis of colony composition revealed that 2 X 10(-8) and 2 X 10(-7) M, 1,25(OH)2D3 induced a 50 +/- 26% increase in the frequency of colonies composed only of monocytes/macrophages in control, but not in the patients' marrow cell cultures. The effect of 2 X 10(-8) and 2 X 10(-7) M 1,25(OH)2D3 on progenitor cell differentiation towards monocytes/macrophages was also observed in marrow cell suspension cultures. Whereas 1,25(OH)2D3 induced a 81-136% increase in the frequency of monocytes in control marrow cells, no effect could be detected on the generation of mature monocytes in marrow cells of the 1,25(OH)2D3 resistant patients. Our results show that marrow granulocyte/macrophage progenitor cells from patients with 1,25(OH)2D3 resistance fail to respond to 1,25(OH)2D3. We thus demonstrate that the effect of 1,25(OH)2D3 on the proliferation and differentiation of haemopoietic progenitor cells is mediated through its binding to specific cytoplasmic receptors.

Psychosexual outcome of assigned females and males with 46,XX virilizing congenital adrenal hyperplasia

Seven genotypic female (46,XX) patients with congenital adrenal hyperplasia, four reared as girls and three reared as boys were evaluated at 16-26 years of age with psychological interviews and testing. A small penis in the three young men produced a practical and psychological barrier that severely injured their personality. In spite of some degree of pre-adolescent tomboyism and a somewhat injured body image, the girls adjusted to their feminine gender identity. It is concluded that in cases of both early and late diagnosis, the genotypic female sex should be preferred.

Interrelated calcium ion and cyclic AMP inhibition of placental lactogen secretion by cultured human term trophoblast

Calcium ion has been shown to have a negative regulatory effect on the secretion of human placental lactogen (hPL). We report an inhibitory effect of cyclic AMP on hPL secretion in a model system of cultured human term trophoblast. Similar results were obtained by modulation of cyclic AMP-phosphodiesterase. The effects of ionophore A23187 and cyclic AMP were non-additive. In searching for the sequence of the common pathway, we found that the ionophore A23187 reduced cyclic AMP concentration and that the inhibitory effect of cyclic AMP was abolished by verapamil, a calcium channel blocker, and by trifluoperazine, a calcium-calmodulin inhibitor. Cyclic AMP seems to mobilize intracellular calcium, and the latter, by way of a calcium-calmodulin complex, modulates the secretion of hPL.

Prostatic ejaculate in assigned males with 46,XX congenital adrenal hyperplasia

Two assigned males with 46,XX congenital virilizing adrenal hyperplasia due to 11 beta-hydroxylase deficiency reported an ejaculation of thick fluid. Chemical analysis revealed that the fluids bore a resemblance to normal prostatic fluids. Extreme virilization in utero seems to have produced both complete virilization of external genitalia and development of a prostate.

Requirement of mineralocorticoid in congenital adrenal hyperplasia due to 11 beta-hydroxylase deficiency

Marginal salt loss occurs in patients with congenital adrenal hyperplasia due to 11 beta-hydroxylase (11-OHase) deficiency treated with dexamethasone and is accompanied by increased PRA. The present study was undertaken to evaluate the effect of the stimulated renin-angiotensin system on pituitary-adrenal suppression. Seven patients with 11-OHase deficiency were subjected to a series of treatments with dexamethasone, cortisol, and combined cortisol and 9 alpha-fluorohydrocortisone. The latter combination suppressed PRA and sodium excretion, and produced better control of the pituitary-adrenal axis, as measured by plasma ACTA and serum 11-deoxycortisol. We conclude that in children with 11-OHase deficiency, PRA needs to be monitored, and when it is elevated, mineralocorticoid replacement is indicated.

The dual effect of calcium on aromatization by cultured human trophoblast

To study the effect of calcium ion on aromatization of an androgenic precursor to estradiol by the placenta, cultured term trophoblasts were used as a model system. Secretion of estradiol into the culture medium was regarded as indicating aromatization, since cells cultured with no androgenic precursors produced only insignificant amounts of estradiol. EGTA, verapamil and ionophore A23187 inhibited aromatization, while trifluoperazine, an inhibitor of the calcium-calmodulin complex, interfered with the stimulatory effect of cyclic AMP on aromatization. We conclude that calcium ion has an essential role in the aromatization of 4-androstene-3,17-dione to estradiol. The calcium-calmodulin complex is required for activation of aromatase by cyclic AMP. However, when flooded with calcium by ionophore A23187, the trophoblast is unable to effectively buffer calcium, and aromatization is inhibited.

Low-set osmotic threshold for vasopressin release in a patient with prolactinoma

This report describes a 38-year-old patient with prolactinoma, without adrenal or thyroid insufficiency, with syndrome of inappropriate secretion of vasopressin due to downward resetting of the hypothalamic osmoreceptors. Random measurements of plasma and urine osmolality revealed an inappropriately high urine osmolality for a given plasma osmolality. Simultaneous plasma vasopressin levels were within normal limits. Urine dilution after water load was normal. During infusion of hypertonic saline, the osmotic threshold was demonstrated at plasma osmolality of 267 mosmol/kg, which is markedly lower than the normal 287.3 +/- 3.3 mosmol/kg. Thirst sensation seemed to be intact. The defect in the osmoreceptor function might have been induced by the tumor mass or by chronic hyperprolactinemia.

The effect of inhibitors on insulin regulation of hormone secretion by cultured human trophoblast

The effect of insulin in physiological concentrations on hormone secretion by human term trophoblast cell culture was studied in relation to insulin control of glucose transport and utilization. Specific inhibitors to these 2 functions were added to the culture, either alone to test for a dose response or with insulin. 2-Deoxy-D-glucose, which inhibits glycolysis, did not change the pattern of response of estradiol and placental lactogen (hPL) secretion to insulin. Phloridzin, an inhibitor of glucose transport, interfered with the stimulatory effect of insulin on hPL secretion, but stimulated insulin inhibition of estradiol secretion when added by itself. The results indicate that hPL response to insulin is dependent on glucose transport, but is independent of glycolysis. Estradiol response is dependent on glucose transport, but is independent of glycolysis.

Defective binding and function of 1,25-dihydroxyvitamin D3 receptors in peripheral mononuclear cells of patients with end-organ resistance to 1,25-dihydroxyvitamin D

Lectin-induced DNA synthesis by peripheral mononuclear cells from 17 normal donors was inhibited (40-60%) by 1,25-dihydroxyvitamin D3 (1,25[OH]2D3) at physiological concentrations (10(-10)-10(-9) M). The lymphocytes acquire specific receptors for 1,25(OH)2D3 upon activation by the lectins. This process precedes the inhibitory effect of 1,25(OH)2D3. We studied lymphocytes from six patients from four different kindreds with the syndrome of hereditary end-organ resistance to 1,25(OH)2D (the so-called vitamin D-dependent rickets type II). In five patients (three kindreds) peripheral blood mononuclear cells did not acquire receptors for 1,25(OH)2D3 upon phytohemagglutinin-induced activation. Moreover, in contrast to normal lymphocytes, the mitogenic stimulation of these patients' lymphocytes by phytohemagglutinin and concanavalin A was not inhibited by 1,25(OH)2D3. Activated lymphocytes of the sixth patient from a fourth kindred exhibited normal binding of [3H]1,25(OH)2D3 but the hormone failed to inhibit the mitogenic stimulation. A similar pattern of the vitamin D effector system was previously observed in fibroblasts cultured from skin biopsies of the same group of patients. The conclusions from these findings are: (a) the inhibition of mitogenic stimulation by 1,25(OH)2D3 is mediated by specific functional receptors to the hormone; and (b) the receptors for 1,25(OH)2D3 in mononuclear cells are probably controlled genetically by the same mechanisms as the effector system in well-characterized target organs of the hormone, such as intestine and kidney.

Hypocalcaemia induced by glucocorticoids in a child with hypoparathyroidism treated with 1-alpha-hydroxyvitamin D3

Glucocorticoids tend to lower the intestinal absorption of calcium, leading to a negative calcium balance. A 7-year-old girl with hypoparathyroidism was maintained as normocalcaemic on 1-alpha-hydroxyvitamin D3 (1 alpha D3) and calcium gluconate lactate. During an episode of aplastic anaemia she was treated with prednisolone, with a subsequent dramatic fall of serum calcium despite 1 alpha D3 treatment and serum 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) in the high-normal range. Glucocorticoids seem to have interfered directly with cellular events responsible for intestinal absorption of calcium.

Normal plasma-urine osmolality relationship in preterm infants on positive pressure mechanical ventilation

Mechanical ventilation with positive pressure has been implicated in the inappropriate release of vasopressin. To examine whether such a phenomenon occurs in infancy, 26 preterm neonates with Respiratory Distress Syndrome were studied. Simultaneous urine and plasma were collected for osmolality determination during mechanical ventilation with positive end expiratory pressure of 4-8 cmH2O. Results were plotted onto our previously described nomogram. The data show normal distribution of plasma to urine osmolality ratio in 25 out of 26 infants. These results do not support the common belief that positive pressure mechanical ventilation in the newborn with RDS provokes inappropriate secretion of vasopressin.

Calcitriol-resistant rickets with alopecia

Four children of two kindred had alopecia associated with severe rickets, resistant to treatment, and caused by defective cytoplasmic and nuclear receptors for the active vitamin D metabolite calcitriol (1,25-dihydroxyvitamin D3). Scalp biopsy specimen revealed a normal number and light microscopic features of the hair and hair follicles. Calcitriol-resistant rickets should be added to the list of inherited disorders of hair growth, and the association of rickets with alopecia needs to be considered in the differential diagnosis of hair loss.

Isolated ACTH deficiency with transitory GH deficiency

A nine-year-old girl, who presented with a severe hypoglycemic coma, proved to have isolated ACTH deficiency, a finding previously reported in only two children. On the initial evaluation, before any treatment, GH did not respond to provocative stimuli. On replacement therapy with hydrocortisone, normal linear growth was observed. Repeated testing while on glucocorticoids replacement four years after the initial attack revealed normal GH response to stimulation test. It is suggested that cortisol deficiency was responsible for the severe hypoglycemic coma and subnormal GH response. A similar mechanism is speculated for the normal growth observed in some patients with apparent deficiency of anterior pituitary hormones, including GH. The possibility of permanent ACTH deficiency and transitory GH deficiency following hypophysitis is discussed.

Does 1,25-dihydroxyvitamin D participate in the regulation of hormone release from endocrine glands?

The presence of receptors for 1,25-dihydroxyvitamin D3 in the pituitary, pancreas, testis, and ovary has raised the question of a possible direct role for 1,25-dihydroxyvitamin D (1,25(OH)2D) in the regulation of hormone synthesis and secretion. To evaluate this problem, six children with the syndrome of resistance to 1,25(OH)2D with rickets and alopecia underwent dynamic tests of insulin, TSH, PRL, GH, and testosterone secretion. Oral glucose loading resulted in normal glucose curves, subnormal peak insulin responses of 12-20 microU/ml in three hypocalcemic patients, and normal peak serum insulin values of 30-40 microU/ml in two normocalcemic patients. Basal serum, TSH, PRL, T4, and T3 concentrations were normal in all patients. Peak serum TSH values after TRH were 11-17 and 16-32 microU/ml in the hypo- and normocalcemic patients, respectively. The PRL response to TRH stimulation in either hypocalcemic or normocalcemic patients was normal [mean 26.2 +/- 5.1 (SD) ng/ml]. Peak serum GH levels were greater than 8 ng/ml in all five patients studied after one or more of the various stimuli. Serum testosterone concentrations after hCG stimulation were normal in the three patients studied (4.1-8.0 ng/ml). Thus, in children with resistance to 1,25(OH)2D, we could find no significant abnormalities in hormone secretion from the pituitary, pancreas, and testis apart from those presumably due to the hypocalcemia itself.

Salt loss in congenital adrenal hyperplasia due to 11 beta-hydroxylase deficiency

Nine patients with 11 beta-hydroxylase deficiency had 13 episodes of gastroenteritis requiring hospital admission and fluid administration. Eight episodes were accompanied by hyponatraemia and salt loss. The salt losing patients were treated with excessive glucocorticoid and those with normal serum sodium concentrations were treated with inadequate glucocorticoid. Excessive glucocorticoid suppressed deoxycorticosteroid secretion, resulting in salt loss.

Plasma and urine osmolality in full-term and pre-term infants

The purpose of the present study was to determine the normal relationship of urine and plasma osmolality in pre-term and full-term infants. Twenty-nine full-term and 35 pre-term babies were studied during the first week of life. Random simultaneous urine and plasma samples were measured for osmolality. Statistical analysis defined the normal relationship of plasma to urine osmolality. This suggests an osmotic threshold of 282 mOsm/kg and 291 mOsm/kg for full-term and pre-term babies, respectively. These values are different from the 285-290 mOsm/kg of adolescents and adults. The nomograms provided may serve as a useful aid in the bedside diagnosis of dysfunctional secretion of vasopressin.

1,25-Dihydroxyvitamin D resistance, rickets, and alopecia

Two unrelated kindreds with four affected children having 1,25-dihydroxyvitamin D resistance, rickets, and alopecia are described. The children exhibited early onset of severe rickets with hypocalcemia, hypophosphatemia, elevated serum alkaline phosphatase levels, and secondary hyperparathyroidism. Radiography showed diffuse demineralization and classic changes of rickets. All affected children had total-body alopecia. Serum levels of 1,25-dihydroxyvitamin D3 were elevated and rose to extremely high values during treatment, with no apparent change in the mineral disorder. However, secondary hyperparathyroidism and hypophosphatemia did remit during treatment despite persistently low calcium levels. Skin biopsy was performed in the parents and affected children in one kindred. Analysis of 1,25-dihydroxyvitamin D3 receptors in cultured fibroblasts indicated apparent normal receptors in the parents and undetectable receptors in both affected children. After long periods of treatment with vitamin D metabolites and mineral replacement, healing took place in the older child in each kindred. These data suggest that the healing occurred spontaneously as the children reached seven to nine years of age rather than as a result of the treatment. The biochemical lesion in these children appeared to be a genetically transmitted defect in the 1,25-dihydroxyvitamin D3 receptor. The mechanisms by which healing was initiated and maintained remain to be elucidated.

The modulation of placental lactogen secretion by calcium: studies with cultured human term trophoblast

Previous reports have documented the negative regulatory effect of calcium ion on the secretion of human placental lactogen by the placenta. Human term trophoblasts were dispersed from term placenta and maintained in monolayer cell culture. Incubation of the cultured trophoblast with EGTA produced a dose-dependent stimulation of placental lactogen secretion. The calcium ionophore A23187 inhibited hormone secretion. This inhibitory effect was eliminated by the addition of the calcium-calmodulin complex inhibitor trifluoperazine. It is concluded that calcium exerts a negative regulatory effect on the secretion of placental lactogen by a mechanism which requires the action of the calcium-calmodulin complex.

1,25-dihydroxyvitamin D resistance, rickets, and alopecia: analysis of receptors and bioresponse in cultured fibroblasts from patients and parents

To investigate further the cellular defects of vitamin D-dependent rickets type II with alopecia, we studied 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] receptors and the response to 1,25-(OH)2D3 in cultured skin fibroblasts from rachitic patients. Our studies included cells from four affected patients from three kindreds and their parents and cells from five normal subjects. We measured total 1,25-(OH)2D3 receptor binding in cell extracts and the capacity of 1,25-(OH)2D3 to induce the enzyme 25-hydroxyvitamin D3-24-hydroxylase (24-hydroxylase) as a marker of functional response. In normal fibroblasts, the 1,25-(OH)2D3 maximal binding capacity was 52 +/- 5 fmol/100 micrograms DNA (mean +/- SE), and the apparent dissociation constant (Kd) was 0.05 +/- 0.01 nM. The maximal induced 24-hydroxylase activity after 1,25-(OH)2D3 treatment was 11.5 +/- 1 fmol/10(6) cells X 30 min, and the dose of 1,25-(OH)2D3 that achieved half-maximal induction was 2.3 +/- 0.3 nM. Fibroblasts from all four rachitic patients had the same defect: no measurable 1,25-(OH)2D3 receptor binding and no detectable response above basal activity even after high doses of 1,25-(OH)2D3. Cells from all parents except one had normal 1,25-(OH)2D3 binding characteristics and normal 24-hydroxylase bioresponse to 1,25-(OH)2D3. One parent despite a normal phenotype had only half the normal level of binding sites and only half the normal bioresponse. In summary, the cultured fibroblasts from four affected children representing three different kindreds with 1,25-(OH)2D3 resistance failed to exhibit detectable 1,25-(OH)2D3 receptors. We postulate that this biochemical defect produced both the inability to respond to 1,25-(OH)2D3 in vitro and the 1,25-(OH)2D3 resistance in vivo. The obligate heterozygotic parents were normal, except for one who had both half the normal number of receptors and half the normal response to 1,25-(OH)2D3. The data confirm the critical role of the receptor in 1,25-(OH)2D3 action and the close coupling of receptor content and functional responsiveness.

Glomerulosa failure in congenital adrenocortical unresponsiveness to ACTH

We report two children of a family with congenital adrenocortical unresponsiveness to ACTH. Repeated stimulation of the adrenal by Synthetic 1-24 ACTH (Synacthen) failed to increase cortisol secretion, but produced significant rises of serum aldosterone. This was, however, associated with increased plasma renin activity. Only when the renin-angiotensin effect was eliminated, by a converting enzyme blocker, did Synacthen fail to affect serum aldosterone. These data support the view that glucocorticoid deficiency in this disorder results from unresponsiveness to ACTH and that development of the zona glomerulosa and normal aldosterone secretion is achieved by action of the renin-angiotensin system.

Salt loss in hypertensive form of congenital adrenal hyperplasia (11-beta-hydroxylase deficiency)

Studies in patients with congenital adrenal hyperplasia due to 11-hydroxylase deficiency (11-OHD) suggest a common defect in the adrenal zona fasciculate and zona glomerulosa. The hypertension in untreated 11-OHD patients is considered to be secondary to the accumulation of deoxycorticosterone as a consequence of inadequate 11-beta-hydroxylation in the biosynthesis of aldosterone, and is alleviated by glucocorticoid suppression. To investigate whether deoxycorticosterone suppression in these patients resulted in loss of salt, 11 patients with 11-OHD aged 4-26 yr were studied. Patients were evaluated during dexamethasone suppression (0.6 mg/m for 2 weeks) while receiving a normal diet and a low salt diet (10 meq Na/24 h). There was no significant change in serum electrolytes, cortisol, 11-deoxycortisol, and DOC during these two dietary regimens. PRA in the recumbent and upright positions on both diets was significantly higher in the patients than in normal subjects. Plasma or urinary aldosterone levels were significantly lower in the 11-OHD patients than in the normal controls. Moderate salt loss occurred during the low salt diet. It is concluded that sodium retention is incomplete in glucocorticoid-treated 11-OHD patients. Partial sodium retention is maintained by increased PRA and a subnormal aldosterone response. 11-OHD patients should be carefully monitored during acute disease states and, when electrolyte imbalance is suspected, treatment with mineralocorticoid should be considered.