The existence of fatty acid binding protein in chicken ovarian granulosa cells was investigated using a fluorescent assay based on the ability of cis-parinaric acid to fluoresce as a result of its interaction with proteins. Cytosolic fractions were prepared from granulosa cells obtained from the first (F1), second (F2), and third (F3) largest preovulatory follicles as well as from a pool of small yellow follicles of the chicken ovary, and each fraction was incubated with different concentrations of cis-parinaric acid. Total fluorescence increased (but fluorescence per milligram protein decreased) as the quantity of cytosolic protein from all follicle types was increased. Cis-parinaric acid fluorescence (which was also dose-dependent) was observed within 2 sec and increased with time reaching a plateau at about 10 sec. It was greater (p < 0.001) in the cytosolic fraction from F3 and small yellow follicle groups compared with F2 and F1 groups. Arachidonic, palmitic, oleic and stearic acids attenuated the fluorescence in dose-dependent fashion in cytosol from all follicle types presumably by displacing cis-parinaric acid from protein. Whereas arachidonic acid was most effective in suppressing fluorescence in fractions from F1 follicles, arachidonic acid lost part of its suppressive potency in fractions from F3 or small yellow follicles, and in these fractions palmitic acid was the most potent suppressor of fluorescence. These results indicate the existence of fatty acid binding protein-like activity in chicken granulosa cells and demonstrate that its concentration is greatest in the immature follicles. This protein could play an important role in the transport of fatty acids within granulosa cells.

The thyroid status was investigated in 26 pregnant African women at term delivery in an iodine-deficient region (Jengere) of Nigeria, West Africa including the measurement of serum T4, T3, TSH, thyroxine binding capacity, TBG, free thyroxine index (FT4I) and the results were matched with those obtained in a corresponding group of 46 women at delivery in Jos, the non-iodine-deficient region which was used as a control. Corresponding cord-blood samples were obtained from all the neonates of the two groups. Twenty-three urinary samples in the former and 14 in the latter group were analysed for iodide levels to ascertain the degree of iodine deficiency. The results demonstrate that compared to the values seen in the Jos group the maternal serum T4, T3 and FT4I levels were significantly reduced in the iodine-deficient group, while TSH, TBG and thyroxine binding capacity were elevated. Cord serum samples showed a corresponding fall in T4 and FT4I levels in the group from the iodine-deficient region, while the T3 levels were significantly elevated with a concurrent significant rise in TSH and TBG levels. Significant correlations were found between the maternal and cord serum T4, TSH, TBG, thyroxine binding capacity and FT4I levels, but not T3. From these findings we suggest that fetal T3 plays an important defensive role against the danger of long-standing environmental iodine deficiency.

The expression of insulin-like growth factors and their binding proteins in normal human peripheral lymphocytes was studied using the reverse transcriptase polymerase chain reaction method and Western ligand blotting. A quantitation of RT-PCR products was used to study the differences between normal and PHA stimulated lymphocytes. Normal freshly collected lymphocytes expressed mRNAs for both IGF-I receptor and IGF-II receptor but no expression of the corresponding growth factors was detectable. After stimulation with phytohemagglutinin the lymphocytes, however, expressed both IGF-I and IGF-II. Of the five IGFBPs examined, unstimulated lymphocytes expressed only IGFBP-2 and -3. Stimulated lymphocytes expressed IGFBP-4 and -5, in addition to IGFBP-2 and -3, whereas IGFBP-1 mRNA remained undetectable. The ligand blotting of lymphocyte conditioned media revealed production of 34K, 43K and 49K IGFBPs. The addition of estrogen, progesterone, IGF-I or growth hormone did not affect secretion of IGFBPs by lymphocytes.

In several animal species the catecholamines stimulate the release of alpha-MSH from the melanotrope cells of the pituitary neurointermediate lobe through beta-receptors. The human hypophysis does not include a well-defined intermediate lobe and the methods for measuring alpha-MSH are often poorly sensitive. Neuroregulation of this hormone in man has thus received little attention. To see whether the adrenergic system is involved in the control of alpha-MSH secretion and whether the latter is independent of that of other peptides derived from proopiomelanocortin, such as ACTH, we studied the effects on plasma alpha-MSH-like immunoreactivity (alpha-MSH-LI), ACTH, and cortisol of some adrenergic drugs active on the beta-receptors. Six normal volunteers underwent the infusion of the following drugs: isoproterenol (0.03 microgram.kg-1.min-1 for 60 min), propranolol (1 mg.min-1 for 5 min followed by 0.1 mg.min-1 for 115 min), propranolol+isoproterenol (infused between 30 and 90 min of propranolol infusion), placebo (saline solution). Isoproterenol increased alpha-MSH-LI at 15 min (p < 0.001). Propranolol induced a fall of alpha-MSH-LI between 30 and 60 min (p < 0.001), followed by a return to preinfusion concentrations beginning at 75 min, and completely prevented the stimulatory effect of isoproterenol. Plasma ACTH and serum cortisol were always unaffected. These results indicate that in man the adrenergic system stimulates alpha-MSH-LI release through beta-receptors, and that alpha-MSH-LI secretion is dissociated from that of ACTH and cortisol. This in turn suggests that separate neuroregulatory mechanisms exist for the melanotrope and corticotrope cells.

Urinary GH excretion reflects average plasma levels. Using a highly sensitive sandwich enzyme immunoassay we determined GH concentrations in the 24 h accumulated urine samples of 54 healthy persons (aged 1.5-90 years), 8 acromegalic patients, 4 acromegalic patients after enucleation of a GH-producing adenoma, 8 patients with partial hypopituitarism and in first morning urine and 12 h accumulated daytime urine of 4 healthy children and 3 children with growth failure. GH secretion is age-dependent, with high rates between ages 1 and 20 (ages 0-20 years: 10.4 ng/g creatinine +/- 6.3 vs age > 20-75 years: 3.1 ng/g creatinine +/- 1.6). An age-dependent increase in urinary GH is found in the pubertal age group (10 ng/24 h +/- 6.8 vs prepubertal group: 4.6 ng/24 h +/- 2.95). GH excretion of patients with acromegaly differs significantly from healthy subjects (72 ng/24 h +/- 49 vs 3.9 ng/24 h +/- 2.3). After a successful operation, acromegalic patients do not differ from the collective norm. Six of 8 patients with partial hypopituitarism show lower GH concentrations in urine than healthy subjects (1.2 ng/l +/- 0.2 vs 2.6 ng/l +/- 1.2), but daily GH output does not differ, since significantly more urine is then excreted. At night, healthy children secrete significantly more GH than during the day (night: 0.16 ng.kg-1 x (12 h)-1 +/- 0.02 vs day: 0.07 ng.kg-1 x (12 h)-1 +/- 0.03), while output is the same for GH-deficient children. Both groups have similar GH daytime output, but GH-deficient children have significantly less nocturnal output.(ABSTRACT TRUNCATED AT 250 WORDS)

We have evaluated the effect of exogenous administration of IGF-I on the thyroid axis in four separate studies: (1) iv bolus injection; (2) single sc injection; (3) seven days' sc treatment, and (4) four months' treatment. Thirteen patients with Laron-type dwarfism (LTD) participated in the investigations. In studies 1 and 2, 10 healthy subjects were also included. Before and during long-term treatment (study 4) six LTD patients underwent a TRH test. IGF-I was administered in a dose of 75 micrograms.kg-1 iv or 120-150 micrograms.kg-1 sc. Single injections of IGF-I caused significant decreases of serum TSH in LTD patients (iv: 1.7 +/- 0.2 to 1.1 +/- 0.1 mU/l; sc: from 2.1 +/- 0.4 to 1.1 +/- 0.2; p < 0.0005). In controls the decrease was for iv from 1.2 +/- 0.2 to 0.8 +/- 0.2 mU/l (p < 0.02) and for sc from 2.0 +/- 0.5 to 0.8 +/- 0.2 mU/l (p < 0.05). Long-term administration of IGF-I induces a transitory decrease of both serum TSH and fT4, followed by a spontaneous rise to pretreatment or even higher values. No changes in T3 were observed. TSH stimulation by TRH was significantly augmented after four months of IGF-I treatment (p < 0.005). The effects of IGF-I can be explained by an early stimulation of somatostatin release causing a decrease in TSH and followed by the development of compensatory mechanisms. All changes were within the normal ranges, not causing abnormal thyroid function.(ABSTRACT TRUNCATED AT 250 WORDS)

Sixteen normally lactating women underwent a double-blind randomized placebo-controlled trial of recombinant human growth hormone (hGH) to assess the effect of hGH on milk production in early lactation. Milk volumes were measured by test weighing procedures of the infants and removal of residual milk on a control day and after 7 days of treatment with recombinant hGH (0.1 IU.kg-1 body weight.d-1) or placebo treatment. Although all women were lactating normally before the study commenced, milk volume in 8 hGH treated mothers was increased (p < 0.02) by 18.5 +/- 1.4% (mean +/- SEM) compared to 11.6 +/- 2.0% in the placebo-treated group (N = 8). No adverse effects were seen with hGH treatment and no major changes noted in milk constituents. The hGH concentrations in milk were low and did not change with therapy. Plasma concentrations of IGF-1 increased significantly within 24 h of hGH treatment and increased further towards the end of the trial to values of 2.6-fold above the pretreatment values. The concentration of IGF-1 in milk was approximately 100-fold lower than those observed in plasma and could only be reliably measured after size exclusion chromatography to remove the interfering influence of IGF binding proteins in the radioimmunoassay. All women treated with hGH showed a small increase in milk IGF-1 concentrations but the values remained within the range of values observed in women receiving the placebo treatment (1.2-4.4 micrograms/l). Growth hormone treatment increased milk volume in normal lactating women during early lactation.(ABSTRACT TRUNCATED AT 250 WORDS)

Six healthy women were examined three times a week during the second trimester. The aim of the study was to test the existence of a monthly cycle in plasma GnRH. Because the kidney plays a dominant part in the elimination of small peptides from the circulation by filtration, the filtered load (P-GnRH x GFR) of GnRH was estimated and tested for a cycle. A mathematical model (parabolas overlaid with a cosine curve and containing parameters for cycle length, cycle amplitude and phase) was used in a multivariate analysis of changes in plasma GnRH, creatinine clearance and GnRH filtered load. We found significant monthly cycles in plasma GnRH (p = 0.003) and in GnRH filtered load (p = 0.004), but no significance for a cycle in creatinine clearance. As an intermediate result we demonstrated that the tubular reabsorption of GnRH was unsaturated for all values of plasma GnRH and GnRH filtered load in question. The increased pregnancy level of plasma GnRH originates in part in the placenta, but we assume that the cycle generator is contained in the maternal neuroendocrine system.

To investigate whether malformations in the offspring of diabetic rats are related to a disturbed embryonic glucose metabolism, lactate production, lactate content and glucose oxidation in embryos of normal and manifestly diabetic rats were measured in vitro during the period of organogenesis. The embryonic production and content of lactate decreased by 90% between gestational days 10 and 11. On both gestational days the embryos of diabetic rats showed increased lactate production and content compared to the embryos of normal rats. The embryonic oxidation of glucose decreased slightly from gestational day 10 to day 11, and the embryos of diabetic rats exhibited a lower glucose oxidation rate than those of normal rats on both days. The lactate production and content in the embryos increased with increasing concentrations of glucose in the incubation medium, whereas the oxidation of glucose was unaffected by the glucose concentration. The results suggest that the embryonic metabolism of glucose is only marginally affected by changes in the availability of glucose. The lactate production rate was higher and the glucose oxidation rate lower in the embryos of diabetic than in those of normal rats, even when the values for these metabolic variables were normalized to the embryonic DNA content. Thus, a causative role for a disturbance of the glucose metabolism in diabetes-induced embryonic dysmorphogenesis could be envisaged.