In an attempt to investigate the clinical significance of anti-pituitary antibodies in patients with hypopituitarism, anti-pituitary antibody in plasma was examined in 10 such patients (7 cases of isolated ACTH deficiency, 1 of partial hypopituitarism, and 2 of Sheehan's syndrome), on two or three occasions with an interval of more than 6 months (longitudinal study). In a total of 16 relatives of these 4 patients (2 cases of Sheehan's syndrome, one in each of partial hypopituitarism and isolated ACTH deficiency) and one patient not involved in the longitudinal study, anti-pituitary antibodies were also examined (family study). Anti-pituitary antibodies reacting with rat pituitary cytoplasmic antigens (pituitary cell antibodies: PCA) and pituitary cell surface antibodies (PCSA) reacting with GH3 cells and/or AtT-20 cells were measured with indirect immunofluorescence. The longitudinal study revealed the disappearance of antibodies in 3 patients, 2 PCA positive and one both PCA and PCSA positive. In 3 patients, altered antibody titers or a newly appearing antibody were found during the follow-up period. In 4 patients, the pituitary antibodies were negative during the follow-up periods. Of 16 family members studied, positive PCA was found in 3 members (2 in the families of patients with PCA positive Sheehan's syndrome, and 1 in the family of the patients with PCA positive partial hypopituitarism). Positive PCSA was found in 4 members (one in each of families of patients with partial hypopituitarism and isolated ACTH deficiency and of two cases of Sheehan's syndrome), and weakly positive PCSA was found in one family member of a patients with PCA positive Sheehan's syndrome. The longitudinal study indicated that anti-pituitary antibodies may disappear during the course of the disease. A family study suggested that some types of hypopituitarism might involve an autoimmune process with a hereditary background for their pathogenesis.

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A6 cells, a continuous cell line derived from kidney of Xenopus laevis, were incubated with [³H]-dexamethasone for 24h. When radioactive compounds in media were separated by reversed phase high pressure liquid chromatography, two radioactive fractions were found. The less polar fraction which contained 91-93% of total radioactivity cochromatographed with dexamethasone, whereas the polar fraction contained 5% of total radioactivity in media. In order to rigorously identify the polar metabolite, large scale cultures were carried out and the polar compound was separated and purified by reversed phase high pressure liquid chromatography. The purified material was analyzed by secondary ion mass spectrometry and nuclear magnetic resonance spectroscopy. By these procedures, this material was identified as 6β-hydroxydexamethasone.
To our knowledge these are the first data indicating that dexamethasone can be metabolized by transporting epithelia such as A6 cells.

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A 28-year-old woman had hypothalamic disorders (amenorrhea, obesity, psychiatric abnormalities, polydipsia and fever) and chronic glomerulonephritis. She alsosuffered from general edema associated with cyclical oliguria and polyuria. Her body weight and plasma osmolality increased during the oliguria phase lasting 2 to 8 days and decreased after paroxysmal polyuria accompanied by the natriuresis. These episodes occurred repeatedly, regardless of the treatment with or without diuretics. The release of arginine vasopressin in response to increased plasma osmolality was exaggerated, but changes in plasma volume did not affect arginine vasopressin release. Plasma atrial natriuretic hormone increased in response to a rise in plasma arginine vasopressin and plasma volume during the oliguria phase, thereby resulting in the diuresis and natriuresis. Therenin-angiotensinaldosterone system was secondarily activated by body fluid depletion and diuretics, and this might play an additive role in general swelling. Plasma gonadal hormones did not change to explain the edema. The mechanism of this cyclical edema remains unknown, but it is likely that hypothalamic dysfunction related to psychiatric abnormalities may exaggerate arginine vasopressin release, and enhanced renal sympathetic activity may cause retention of Na and water, and the increase in atrial natriuretic hormone release responding to the plasma volume expansion may bring about the diuresis and natriuresis.

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The present study was designed to clarify the effects of dietary calcium (Ca) intake on serum BGP (osteocalcin) levels. Twelve women with a mean age of 21.2 years participated in the study. After one week of normal Ca intake (mean±SE, 535±2mg/day), a low-Ca diet (163±1mg/day) was given for one further week. Additional asparagine Ca (3g as Ca/day) was also given to half of the subjects. Serum total and ionized Ca concentrations as well as BGP, PTH and 1, 25(OH)₂D₃ were measured at the end of each period. Amounts of Ca and hydroxyproline excreted in urine were also determined. The plasma level of ionized Ca was significantly increased without any change in total Ca in either group. Low and high Ca intake decreased and increased urinary Ca excretion by 28% and 56%, respectively. Serum levels of BGP and 1, 25(OH)₂D₃ were significantly augmente along with a transient increase in urinary hydroxyproline excretion after Ca deprivation. These results suggest that serum BGP is increased after one week of Ca restriction in healthy subjects.

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To clarify the maturation process of the pituitary-thyroid axis during the perinatal period, thyrotropin (TSH) response to thyrotropin releasing hormone (TRH) and serum thyroid. hormone levels were examined in 26 healthy infants of 30 to 40 weeks gestation. A TRH stimulation test was performed on 10 to 20 postnatal days. Basal concentrations of serum thyroxine (T4), free thyroxine (free T4) and triiodothyronine (T3) were positively correlated to gestational age and birth weight (p<0.001-0.01). Seven infants of 30 to 35 gestational weeks demonstrated an exaggerated TSH response to TRH (49.7±6.7μU/ml versus 22.1±4.8μU/ml, p<0.001), which was gradually reduced with gestational age and normalized after 37 weeks gestation. A similar decrease in TSH responsiveness to TRH was also observed longitudinally in all of 5 high responders repeatedly examined. There was a negative correlation between basal or peak TSH concentrations and postconceptional age in high responders (r=-0.59 p<0.05, r=-0.66 p<0.01), whereas in the normal responders TSH response remained at a constant level during 31 to 43 postconceptional weeks. On the other hand, there was no correlation between basal or peak TSH levels and serum thyroid hormones. These results indicate that (1) maturation of the pituitary-thyroid axis is intrinsically controlled by gestational age rather than by serum thyroid hormone levels, (2) hypersecretion of TSH in preterm infants induces a progressive increase in serum thyroid hormones, and (3) although there is individual variation in the maturation process, the feedback regulation of the pituitary-thyroid axis matures by approximately the 37th gestational week.

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The effect of suckling on vasoactive intestinal polypeptide (VIP) gene expression in the hypothalami was studied during the postpartum period in rats. Female rats were divided into two groups immediately after delivery. In one group, a mother was housed with 8 pups, and in the other, without any pups. The former group was named S (+) and the latter S (-). On days 0, 3, 6, 9 and 12 after delivery, the mothers were killed by decapitation. Hypothalamic VIP mRNA was measured by RNA dot hybridization. Although the VIP mRNA level showed no significant change after delivery in the S (-) group, VIP mRNA in the S (+) group on days 6, 9 and 12 increased to 1.6, 3.5 and 2.1 times higher than the level observed on day 0, respectively. These results suggest that suckling induces the synthesis of VIP after 6 postpartum days.

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The pharmacokinetics of total and free prednisolone (PSL) in six healthy men, with or without pretreatment with oral glycyrrhizin (GL), was investigated to confirm whether oral administration of GL influences the metabolism of PSL in man. Each subject received an intravenous administration of 0.096 mg/kg of prednisolone hemisuccinate (PSL-HS) with or without pretreatment with 50 mg of oral GL four times. Blood samples were taken from a peripheral vein at 5, 10, 15, 30, 45 min and 1, 1.5, 2, 3, 4, 6, 8, 10, 12 and 24 h after the start of PSL-HS infusion. The concentrations of total PSL in plasma were analyzed by high-performance liquid chromatography, and the free PSL was measured by an isocolloidosmolar equilibrium dialysis method. The pharmacokinetic parameters of PSL were determined by non-compartment analysis. Oral administration of GL was found to significantly increase the concentrations of total PSL at 6, 8 h, and of free PSL at 4, 6 and 8 h after PSL-HS infusion. Moreover, oral administration of GL was also found to modify the pharmacokinetics of both total and free PSL. After oral administration of GL, the area under the curve (AUC) was significantly increased, the total plasma clearance (CL) was significantly decreased, and the mean residence time (MRT) was significantly prolonged. However, the volume of distribution (Vdss) showed no evident change. This suggests that oral administration of GL increases the plasma PSL concentrations and influences its pharmacokinetics by inhibiting its metabolism, but not by affecting its distribution.

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The effect of phosphorylation of insulin receptor with adenosine 3', 5'-cyclic monophosphate-dependent protein kinase (A kinase) on its insulin binding activity was investigated by using insulin receptors prepared from rat liver in vitro. A 95 KDa protein was phosphorylated by stimulation of insulin receptor kinase. This protein was also phosphorylated by A kinase. Analysis of phosphoamino acid showed that tyrosine residue (s) was phosphorylated by activation of insulin receptor kinase, whereas phosphoserine and phosphothreonine were dominantly generated by activation of A kinase.[¹²⁵I] Iodoinsulin binding activity was decreased by prior phosphorylation of the receptor with A kinase. Scatchard analysis showed that the affinity for insulin was decreased by the phosphorylation with A kinase. Although the maximal activity of insulin receptor kinase was not affected by phosphorylation with A kinase, the insulin concentration which induced half maximal activity (ED₅₀) of the receptor kinase was increased by the phosphorylation with A kinase.
These results suggested that counter regulatory hormones whose actions are mediated by the generation of adenosine 3', 5'-cyclic monophosphate regulate the insulin binding to the a subunit through phosphorylation of the β subunit of insulin receptor.

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In a 30-year-old woman with amenorrhea due to hyperprolactinemia, serum PRL increased to twice the basal amount in response to growth hormone-releasing hormone (GHRH). Roentogenological studies revealed no pituitary adenoma but empty sella. Bromocriptine therapy normalized serum PRL and made the paradoxical response to GHRH disappear. The paradoxical response did not occur in any of eight other patients with hyperprolactinemia due to prolactinoma. Although this case is rare, GHRH stimulates PRL as well as GH release remarkably in some cases with hyperprolactinemia without a GH-producing tumor.

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In this study we investigated the response of the rat fetal hypothalamo-pituitary-adrenal (HPA) axis to an acute maternal stress in late gestation.
On day 20 of gestation, pregnant rats were exposed to forced immobilization stress for up to 60min. In mothers, a significant increase in plasma ACTH and corticosterone (B) was observed at 20 and 60min. The ACTH content in the maternal pituitary decreased significantly at 60min. Fetal blood pH was decreased by the maternal stress, showing a hypoxic condition of the fetus. Fetal plasma ACTH increased transiently at 20min. Fetal plasma B increased at 20 and 60min. ACTH in the fetal pituitary and the placenta did not show marked changes due to the maternal stress.
Pregnant rats on day 18-21 of gestation were subjected to a 20min maternal stress. In the basal condition without stress, fetal plasma ACTH and B showed parallel ontogenic patterns, having a peak value on day 19 of gestation. Fetal plasma ACTH as well as plasma B were increased significantly by the maternal stress at all points evaluated. These results indicate that fetal hypoxia is important in stress transmission to the fetal HPA axis in this type of maternal stress, and the fetal HPA axis responds to the stress as early as day 18 of gestation.

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The phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA), a potentactivator of Ca²⁺-and phospholipid-dependent protein kinase (C kinase), stimulates luteinizing hormone (LH) release from rat pituitary cells. The actions of TPA upon LH release were compared with those of the GnRH superagonist [D-Ala⁶] des-Gly¹⁰-GnRH N-ethylamide (GnRHa) in cultured pituitary cells. LH release was stimulated by 0.1nM TPA and the maximum response at 10 nM TPA was 50% of the LH response to GnRHa. The ED50 values for TPA and GnRHa were 1.2 and 0.037 nM, respectively, and the maximum stimulatory effects of TPA and GnRHa on LH release were not additive. GnRHa-stimulated LH release was decreased by calmodulin (CaM) antagonists including pimozide, trifluoperazine, W5 and W7, being most effectively reduced (by 70%) by 10μM pimozide. In contrast to their inhibition of GnRH action, these antagonists enhanced TPA-stimulated LH release, so that 10μM pimozide and W7 doubled the maximum LH response. The potent GnRH antagonist [Ac-D-p-Cl-Phe^1'2, D-Trp³, D-Lys⁶, D-Ala¹⁰] GnRH, which completely inhibited GnRHa-stimulated LH release with ID₅₀ of 6.8 nM, also reduced maximum TPA-stimulated LH release by about 50%. These results suggest that both Ca²⁺/CaM and C kinase pathways are involved in the LH release mechanism, and indicate that C kinase plays a major role in the action of GnRH upon gonadotropin secretion. The synergism between CaM antagonists and TPA suggests that blockade of CaM-mediated processes leads to enhanced activation of the C kinase pathway, possibly by removal of an inhibitory influence. Furthermore, the partial inhibition of TPA-stimulated LH release by a GnRH antagonist suggests that the pathway (s), specifically connected with LH release in the diverse effects of C kinase, might be locked by the continuous receptor inactivation by antagonist and indicates the complicated pathways which diverge from the receptor and converge into specific cellular response.

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Protein kinases were separated from rat kidney nuclear extract by hydroxylapatite column chromatography. Five (I-V) different protein kinases were isolated when histone was used as a substrate. Two (I and III) of them stimulated phosphorylation of c-erb A-β protein (50 kDa) expressed in Escherichza coli. The c-erb A product has an activity of high affinity T₃ binding. One (I) of the kinases was dependent on cyclic adenosine 3', 5'-monophosphate (cyclic AMP). The other kinase (III) was not dependent on cyclic nucleotides. The latter kinase was eluted from hydroxylapatite column with 0.05 M PO₄ at pH 7.4. The sedimentation coefficient (s) estimated by continuous sucrose density gradient centrifugation was approximately 6.0.Km values for ATP were estimated by double reciprocal analyses, which gave 110.0μM in the protein kinase I (in the presence of 10^-6M cyclic AMP) and 25μM in the protein kinase III, respectively. The data showed that 1.0 mol phosphate was incorporated into 80 mol of c-erb A protein (50kDa) either in the presence of protein kinase I (with 10^-6M cyclic AMP) or in the presence of protein kinase III. These results suggested that there are protein kinases for c-erb A protein, whose functional properties are similar to those of nuclear T₃receptor, in rat kidney nuclei.

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In order to ascertain the role of delta receptors in the control of gonadotropin secretion, a preferential delta receptor antagonist ICI 143, 129 was microinjected into the third ventricle through chronically implanted cannulae and the effects on the serum concentration of luteinizing hormone (LH) and prolactin (PRL) were determined in female rats in proestrus. When the injection was given at 1030 h, ICI 154, 129 (50μg) exerted no significant effects on either LH or PRL. However, in the rat given a microinjection of ICI 154, 129 at 1300h, an afternoon rise in LH occurred in advance and was of greater magnitude, with the peak time more than 1 h earlier and the peak amplitude approximately 100% greater than that in the control rat, respectively. The injection also suppressed the PRL rise during the plateau phase. The results indicate that delta receptors are involved in the mediation of the inhibitory influence of endogenous opioids on the surge of LH in proestrus, and that delta receptors mediate the facilitatory influence of opioids on the PRL surge during the plateau phase.

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An 11-year-old girl with silent thyroiditis associated with a transient increase in serum IgM and thyroid hormone is described. The levels of serum IgM decreased from 4.38g/L to 3.35g/L after 1.5 months at the same time as thyroid hormones returned to normal. An unidentified antecedent infection or exposure to antigen causing the increase in serum IgM might have triggered the occurrence of silent thyroiditis in this patient, although a search for viral antibodies revealed no significant titer changes during the course of the disease.

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This retrospective study serves as an inquiry into the common practice of long-term administration of small maintenance doses of either methyl-mercaptoimidazole (MMI) or propylthiouracil (PTU) to Graves' hyperthyroid patients who became euthyroid with primary large doses of the same drugs.
One hundred and two patients with Graves' hyperthyroidism treated with antithyroid drug (ATD) were studied. Sixty-one were treated with conventional long term therapy and 41 were treated with short-term therapy. Small maintenance doses of ATDs were not administered to the short-term therapy patients. The duration of long-term therapy was 28.6±20.2 months (from 12 to 48 months) and that of short-term therapy was 8.4±1.8 months (from 5 to 11). Post therapy and follow-up observation continued for 19.0±2.7 months (16-25 months) in both long-term and short-term patients. Of the 61 long-term therapy patients, 20 were relapsed and 41 (67.2%) continue to remain in remission. So too, of the 41 short-term therapy patients, 14 relapsed and 27 (65.9%) still remain in remission. There was no statistical difference between the long-term and short-term therapy group in age, sex, duration of symptoms before diagnosis, antithyroid antibodies, radioactive iodine uptake, free thyroid hormone levels or goiter size before treatment or in TBII levels at cessation of ATD.
It is concluded that ‘short-term ATD therapy’ without a maintenance dose is sufficient and saves several months of the patient's and clinician's time.

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