The first objective of this research was to define the capacity of corpora lutea of pig to secrete estradiol in the presence of an androgen substrate which was testosterone. The second objective was to define the synergism between gonadotropic hormones such as LH, FSH, and PRL and testosterone as measured by estradiol and progesterone secretion by two types of porcine luteal cells. Luteal cells were collected from newly forming corpora lutea (0-3 days after ovulation) and from mature corpora lutea (8-10 days after ovulation). After dispersion, luteal cells were suspended in medium M199 supplemented with 10% of calf serum and grown as monolayers at 37°C. Control cultures were grown in medium alone while other cultures were supplemented with either testosterone alone at a concentration of 1×10^-7M or with 10, 100, 500ng LH plus testosterone, 10, 100, 500ng FSH plus testosterone or 10, 100, 500ng PRL plus testosterone. After 2 days of cultivation all cultures were terminated and media were frozen at 20°C for further steroid analysis. Testosterone added to the culture medium in the absence of gonadotropins was without effect on estradiol and progesterone secretion by luteal cells collected in the corpora lutea of the early luteal phase. On the other hand testosterone added to the medium significantly increased progesterone and estradiol secretion by cultured luteal cells collected in the midluteal phase of the cycle. No additive stimulatory action of gonadotropins and testosterone on progesterone secretion was observed in cultures of luteal cells from the early luteal phase but this was not the case in cultures of luteal cells from the midluteal phase. The stimulatory action of PRL and FSH added with testosterone to the culture medium on estradiol secretion by luteal cells collected was observed. Luteal cells from midluteal phase responded only to FSH and testosterone in terms of estradiol secretio
In conclusion, testosterone alone or together with gonadotropins changed luteal steroidogenesis which was different in cultures from early and midluteal cells. This suggests the involvement of different cellular mechanisms responding to gonadotropins of luteal cells from each of the two luteal phases. Pig corpus luteum which is initialy responsive to PRL and FSH alone later becomes unresponsive unless androgen is available.

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Histidyl-proline diketopiperazine [cyclo (His-Pro)] has recently been shown to inhibit prolactin (PRL) secretion in vitro and in vivo. This peptide is well known as a metabolite of thyrotropin-releasing hormone (TRH), which is one of the endogenous secretagogues of PRL. In this study, we investigated the effect of cyclo (His-Pro) on the cytosolic Ca²⁺ concentration ([Ca²⁺] i) in cultured lactotrophs by using a lactotroph-enriched fraction separated from female rat pituicytes by centrifugal elutriation. TRH (10nM) induced a rapid rise in [Ca²⁺] i in the lactotrophs, followed by a plateau phase of prolonged increase in [Ca²⁺] i. In contrast, the addition of 100μM of cyclo (His-Pro) caused no changes in the basal level or the TRH-induced plateau response of [Ca²⁺] i. Although pretreatment with cyclo (His-Pro) tended to decrease the biphasic increase in [Ca²⁺] i induced by TRH, the inhibitory effect was not statistically significant. These results demonstrated that cyclo (His-Pro) has no effect on [Ca²⁺] i in lactotrophs, and does not affect the TRH-induced increase in [Ca²⁺] i, indicating that the inhibition of PRL secretion by cyclo (His-Pro) may be primarily mediated by other intracellular messengers such as cyclic nucleotides and secondarily involved in other inhibitory systems including that of dopamine.

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By using an in situ rat hindquarter perfusion, we evaluated ketone body utilization and its metabolic effects in the resting muscle of 24h fasted normal and streptozotocin (STZ)-diabetic rats. Under the perfusion with ketone body-supplementation (1 mM each of acetoacetic acid (AcAc) and 3-hydroxybutyric acid (3-OHB)), the AcAc and 3-OHB uptake of STZ-diabetic rats was significantly (P<0.05) smaller than that of normal rats. This might be explained by the low enzyme activity of 3-oxoacid CoA transferase demonstrated in the hindlimb muscles of STZ-diabetic rats and this reduced ketone body uptake would be one of the causes of the development of diabetic ketoacidosis. The glucose uptake and the phosphofructokinase (PFK) activity of normal rats were significantly (P<0.05) higher than those of STZ-diabetic rats. In both normal and STZ-diabetic rats, the glucose utilization and PFK activity of the muscles in the ketone body-supplemented condition were significantly (P<0.05) lower than those in the non-supplemented condition. This inhibition of glucose utilization by ketone bodies should be due to the mechanism by which the oxidation of ketone bodies inhibits PFK in the muscle.

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In order to know the contribution of adrenal and gonadal androgens to the development of the side gland of Suncus murinus, we studied the effects of gonadectomy and adrenalectomy on gland thickness and the plasma levels of testosterone, androstenedione (Δ⁴-dione) and dehydroepiandrosterone (DHA). In males, castration decreased gland thickness to 71% of the control. The plasma level of Δ⁴-dione and testosterone were also decreased from 4.16±0.50 and 0.65±0.10ng/ml to 1.44±0.17 and 0.12±0.02ng/ml, respectively. Adrenalectomy following castration caused no notable additional decrease in gland thickness, although the plasma levels of Δ⁴-dione and DHA were further decreased by this treatment. In females, ovariectomy affected neither gland thickness nor plasma androgen levels, except for a peculiar rise in the plasma concentration of Δ⁴-dione. In contrast, adrenalectomy in addition to ovariectomy decreased gland thickness to 63% of the control and the plasma concentrations of Δ⁴-dione and DHA from 1.43±0.26 and 0.43±0.05ng/ml to 0.37±0.11 and 0.10±0.04ng/ml, respectively. Therefore, testicular androgens are required for the male side gland to fully develop, whereas in the female adrenal androgens are important for the maintenance of sebaceous gland activitiy and Δ⁴-dione is quantitatively more important than DHA. One hour after the intraperitoneal administration of [³H]Δ⁴-dione, dihydrotestosterone was found to be the major androgen bound to nuclei of the side gland. Thus, the side gland can utilize Δ⁴-dione as a precursor of a more active androgen. The side gland seems to be a useful model for understanding the role of adrenal androgens in target tissues.

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It has been demonstrated that hyperprolactinemia is sometimes present even in patients with idiopathic diabetes insipidus (DI). In this study, we examined the responses of serum prolactin (PRL) to hypertonic saline infusion and TRH injection in 11 patients with idiopathic DI diagnosed by clinical examinations. Serum sodium in these patients (147.5±3.2mEq/L) was significantly higher at baseline than in normal subjects (139.7±2.4mEq/L). The plasma arginine vasopressin (AVP) level was significantly lower in DI (0.42±0.24pg/ml) at baseline than in normal subjects (2.53±1.03 pg/ml). However, the serum PRL level in both groups did not differ significantly except in one patient with idiopathic DI (35.6ng/ml). There was no significant correlation between the basal serum sodium and basal serum PRL in either group. After an infusion of hypertonic saline, the serum sodium level gradually increased to 155.6±3.4mEq/L in DI and to 146.5±4.3mEq/L in the normal subjects. However, this increase did not affect PRL secretion in either group. PRL response to TRH was essentially normal in all patients with idiopathic DI. These results indicate that the secretion of PRL is not generally affected by chronic mild hypernatremic hypovolemia in the patients with idiopathic DI.

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We have examined a patient with progressive systemic sclerosis (PSS) who had increased serum T3 (235ng/d/) and T4 (13.2μg/dl) and low 24-h thyroidal 1231-uptake (1.2%). A diagnosis of silent thyroiditis was made on the basis of the clinical course and laboratory and histopathologic findings. Simultaneous measurement of serum anti-thyrotropin receptor antibody (TRAb) showed a negative value (-49.0%) which suggested the presence of and-TSH antibody. Further examination by immune precipitation with 125I-bovine TSH (bTSH) and also with 1251-human TSH (hTSH) revealed the presence of and-bTSH antibody but not anti-hTSH antibody in his serum y-globulin. The significance of the association of PSS, silent thyroiditis, and anti-bTSH in one individual is discussed.

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The authors report a very rare case of pituitary adenoma producing both GH and ACTH. A 29-year-old female was admitted with obesity, amenorrhea, acromegaly, hirsutism, excessive pigmentation, acne, and diabetes mellitus. Computed tomography revealed an intrasellar tumor 16mm in height, with a destroyed sellar floor. The blood concentrations of GH, ACTH and cortisol were increased (GH: 92ng/ml, ACTH: 94pg/ml, cortisol: 18.3μg/dl). No diurnal variation in the amount of cortisol was observed. The urinary 17-OHCS was suppressed by 8 mg but not by 2mg of dexamethasone. A subtotal adenomectomy was then performed through the transsphenoidal approach, which led to a sufficient reduction of both blood GH and ACTH (cortisol). Histologically the tumor was an acidophilic pituitary adenoma. Immunoperoxidase staining showed diffuse GH and sporadic ACTH producing cells, but failed to show any cells producing both hormones. The electron micrograms of neoplastic cells showed the ultrastructural characteristics of respective GH and ACTH cells. Another increase in both GH and cortisol, which occurred 19 months after the operation, has been controlled by bromocriptine administration. This case may be the first reported case of a pituitary adenoma producing both GH and ACTH, not accompanied by prolactin (PRL) hypersecretion, which has been fully confirmed endocrinologically and histopathologically.

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We have previously reported that human placental cytotrophoblasts (C-cells) contain nuclear 3, 5, 3'-triiodo-L-thyronine (T₃) receptors. Using a C-cell culture system, the present study wa undertaken to clarify some of the effects of T₃ and EGF on trophoblastic cells. C-cells were purified from human term placenta by treatment with trypsin-DNAse and percoll gradient centrifugation aggregated, then fused, differentiating into multinuclear syncytiotrophoblasts (S-cells) with incubation times up to 96 h in vitro. As the incubation time increased, the number of immunocytochemically reactive cells with antibodies to hCG-α, hCG-β and hPL increased. Anti-EGF antibody reacted only with the initial C-cells, while anti-EGF receptor antibody reacted only with fused S-cells. Maximum secretion of hCG and hCG-cv by the cultured cells was evident only when the cells were cultured in T₃ (10^-8 M) or EGF (10 ng/ml) containing medium. When the initial cells were exposed to 10^-8M T₃ from 0 to 48 h of incubation, the secretion in 48-96 h was significantly accelerated. However, exposure from 48 to 96 h had no effect on peptide excretion. Although an exposure of these cells to 10 ng/ml EGF during 48-96 h of incubation stimulated the secretion of hCG and hCG-α, 0-48 h exposure did not produce any positive effect regardless of incubation time. These results indicated that the main target cell of T₃ is the C-cell, while that of EGF is the S-cell. Furthermore, it is suggested that the interaction between T₃ and its receptor facilitated functional cell differentiation. It is possible to propose a paracrine/autocrine control mechanism in which EGF synthesized by C-cells acts on S-cells.

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The effects of microinjection of naloxone, an opiate receptor antagonist, into the medial preoptic area (MPO) and diagonal band of Broca (DBB) on luteinizinghormone (LH) and prolactin (PRL) secretion were examined in the intact male rat and female ratin diestrus 1. In both the male and female rats, the injection of 50 μg naloxone at 1300h produced an acute, two- to three-fold increase in serum LH, attaining the peak at 20min. The PRL concentration in the female 20 min-2h after the injection was significantly lower than in the saline-injected rat. In the male rat, naloxone caused a decrease in the PRL concentration in the late afternoon when a small rise occurred in the saline-injected rat, although it caused no immediate changes. In addition to these hypophysiotropic effects, naloxone injected in the MPO and DBB unexpectedly had seizurogenic actions. More than 40% of the animals of both sexes given an injection of naloxone had behavioral seizures, which began after about 20 min and were repeated intermittently at 15-20 min intervals through the sampling period of 6 h. In the LH and PRL response to naloxone, there was no significant difference between animals with and without seizure response in both sexes. The results suggest that in the preoptic opioid system there is no difference according to sex in the control of LH, and only a small one, if any, in the control of PRL. Further, on the basis of previous reports, there is a GABAergic system in the preoptic region, that is antagonized by naloxone and causes the activation of cortical neuronal activity.

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To evaluate the effect of perinatal factors and sampling methods on thyroid stimulating hormone (TSH) and thyroid hormone levels in cord blood, serum TSH, free thyroxine (FT₄) and free triiodothyronine (FT₃) concentrations were measured in 124 healthy term neonates. Eighty-eight infants were born in normal vaginal deliveries, 25 were delivered by vacuum extractor and 11 by Cesarean section. There was no significant difference among the three infant groups in the mean TSH levels. Birth weight, the infant's sex, duration of labor and uterotonic agents had no effect on cord serum TSH and free thyroid hormone levels in the neonates born by normal vaginal delivery. To assess the adequacy of specimen collection, mixed cord blood samples, obtained by a direct application of cord on a filter paper, and venous blood withdrawn with a plastic syringe were collected in another 200 infants. There was a significant linear correlation in the TSH concentration in mixed cord blood and cord venous serum from the same individuals, while a poor correlation was found in T₄ values from two specimens. Our results suggest that the TSH value in cord blood is less influenced by perinatal factors, including the sampling method, and the mixed cord blood collected by this technique might be a feasible alternative specimen for a TSH screening program with cord blood which is useful in countries where neonatal blood is not available.

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Urinary N-acetyl-β-D-glucosaminidase (NAG) activity was measured longitudinally in 12 patients with Graves' disease, 5 patients with subacute thyroiditis, and 1 patient with silent thyroiditis, and compared with that of 36 normal controls. The patients with Graves' disease and subacute thyroiditis were treated with anti-thyroid drug (methimazole or propylthiouracil) and prednisolone, respectively. On the other hand, no treatment was given to the patient with silent thyroiditis. Since two patients with Graves' disease clearly showed transient deterioration of the thyroid function during the treatment period, data from these two patients were separately investigated. Urinary levels of NAG in the remaining ten patients with Graves' disease before, 1, 3, 6 and 12 months after the treatment were 15.59±7.93 (SD), 8.96±6.82, 4.39±2.33, 3.46±2.24, and 3.63±2.38 U/g.creatinine (g.Cr.), respectively. Those obtained before, 1 and 3 months after the treatment were significantly higher than those of the controls (2.85± 1.12 U/g.Cr.). Free thyroid hormone levels became normal or low 3 months after the treatment. The two Graves' patients mentioned above showed a transient increase in urinary NAG with concomitant changes in free thyroid hormone levels. Urinary NAG levels in the patients with subacute thyroiditis before, 2, 4, and 6 weeks after the treatment were 16.56± 10.97, 6.76±2.79, 3.14±0.48 and 3.70± 1.44 U/g.Cr., respectively. Those obtained before and 2 weeks after the treatment were significantly higher than those of the controls. Free thyroid hormones were normal 2 weeks after therapy. Urinary NAG in the patient with silent thyroiditis was 9.60 U/g.Cr. on the first visit and gradually decreased. Urinary NAG was still high 1 month after the first consultation while thyroid function became normal. A positive correlation between the levels of urinary NAG and free thyroid hormones was also observed in each group. These results indicate that excessive thyroid hormones may induce urinary excretion of NAG and the fall in serum thyroid hormone levels precedes that in the urinary NAG level. The present results also suggest that urinary NAG activity is a useful tool to use in assessing thyroid function in patients with thyroid disorder.

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Two cases of acute attack of pseudogout associated with primary hyperparathyroidism are reported. Case 1 suffered from acute pain and swelling of the right ankle and dorsal of the right foot. Case 2 suffered from unknown fever and pain of the bilateral jaw, shoulder, elbow, wrist and knee joints. Postoperative radiological studies revealed the association of chondrocalcinosis in both cases. Synovial fluid in case 2 was aspirated and analyzed for calcium pyrophosphate dihydrate crystal by microscopic examination.

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We report a rare case of a 57-year-old female patient with Cushing's disease who had clinically and biochemically proven cyclicity. There were periodic increases in plasma ACTH and cortisol and urinary free cortisol and 17-OHCS. Plasma CRH was undetectable and plasma ACTH responded to exogenous CRH when basal plasma cortisol was relatively low. Neither plasma ACTH nor cortisol responded to dexamethasone (oral and intravenous) but plasma ACTH was clearly suppressed by cortisol infusion. With 40mg/day bromocriptine, the periodic hypercortisolemia disappeared and the patient was maintained on remission. The response of plasma cortisol to dexamethasone suppression test was also normalized.

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We found symptomatic hyponatremia in four elderly patients in which serum sodium (Na) levels ranged from 101 to 122 mEq/l. All 4 patients had low levels of plasma adrenocorticotropic hormone (ACTH), serum cortisol, and urinary excretion of 17-OHCS, and poor responses of ACTH to exogenous insulin and antidiuretic hormone (ADH). Other pituitary hormones were all normal. They were therefore diagnosed as having isolated ACTH deficiency. Plasma ADH was relatively high despite hypoosmolality which was associated with the hyponatremia. Water loading test revealed impaired water excretion and poor suppression of plasma ADH. Replacement with 20-30 mg hydrocortisone completely restored the serum Na level and restored the plasma ADH level to the normal range in all 4 patients. Other factors such as decreased glomerular filtration, enhanced urinary Na loss and decreased Na intake were also included. These results indicate that there is marked hyponatremia and that in the presence of hypoosmolality the sustained secretion of ADH is the key factor in causing the impaired water excretion and hyponatremia in isolated ACTH deficiency.

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A 46-year-old man, presenting with headache, nausea, and lassitude, was diagnosed as having diabetes mellitus and hyponatremia, and admitted to Tohoku University Hospital. Insulin treatment improved the hyperglycemia but aggravated hyponatremia, which was proved to be elicited by the inappropriate secretion of antidiuretic hormone (SIADH). An acute water load failed to suppress ADH release in the supine posture but slightly increased plasma atrial natriuretic peptide (ANP). On the other hand, plasma ADH markedly increased in response to an upright posture, accompanied by a fall in blood pressure and a rise in heart rate. After treatment with droxidopa “a sympathomimetic drug”, ambulatory blood pressure gradually increased and hyponatremia disappeared. However, blood pressure and ADH responses to upright posture were not improved by treatment with the drug. Moreover, plasma ADH was still not sufficiently suppressed by acute water loading in the supine position, but plasma ANP markedly increased, thereby resulting in urinary dilution and natriuresis. These results suggest that exaggerated ADH release (SIADH) was brought about by the baroreceptor reflex stimulated by the postural hypotension, and also by the impaired osmoregulation associated with diabetic neuropathy, and that droxidopa improved cardiovascular function and increased ANP release with resultant urinary dilution and natriuresis in spite of slightly increased ADH release.

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The in vitro effects of endothelin-1 (ET-1) and endothelin-3 (ET-3) on the release of prostaglandin (PG) E₂ from the rat median eminence were investigated. The addition of ET-1 from 10^-9M to 10^-6M stimulated PGE₂ release in a dose-dependent manner (from 10.5±2.1 to 54.4±5.6pg/ME fragment/ 30 min; mean±SEM, p<0.001). ET-3 also stimulated the release of PGE₂ from 10^-7 M to 10^-5 M dose dependently (from 18.1±0.7 to 60.9± 17.4pg/ME fragment/30 min p<0.05). The time course effect of ET-3 (10-6 M) showed that PGE₂ release was stimulated within five minutes (control, 1.5±0.5; ET-3, 15.8±3.0pg/ME fragment/5 min, p<0.01). These results suggest that ET-1 and ET-3 have some physiological effects on the rat median eminence.

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