Abstract. Ghrelin has a stimulating effect on arginine vasopressin (AVp). however, it is not known whether GhRp-2, a synthetic ghrelin receptor agonist, also has a stimulating effect on AVp release in men. to determine whether the GhRp-2 test is useful for assessing AVp secretion, blood Acth, Gh, FSh, Lh, pRL, tSh and AVp levels, as well as glucose, osmolality, sodium and hematocrit, were measured before and 15, 30, 45 and 60 min after an intravenous bolus of 100 µg GhRp-2 in 10 healthy men with and without fasting. blood pressure was measured at 15-min intervals. AVp secretion was not stimulated by the GHRP-2 test with and without fasting. There were no significant differences in hematocrit, blood pressure and plasma osmolality before and after GFRP-2 injection, although significant (p<0.001) peak blood Gh, and Acth and pRL levels were observed 30 and 15 min after GhRp-2 injection with and without fasting, respectively, and the maximal peaks were significantly (p<0.05) higher with fasting than without fasting. these results suggest that AVp secretion is not stimulated by the GhRp-2 test both with and without fasting, though Gh, Acth and pRL levels were higher with than without fasting.

BackgroundPheochromocytomas are rare catecholamine-producing neuroendocrine tumors. Hypertension secondary to pheochromocytoma is often paroxysmal, and patients occasionally present with sudden attacks of alternating hypertension and hypotension. Spontaneous, extensive necrosis within the tumor that is associated with catecholamine crisis is an infrequent complication of adrenal pheochromocytoma, but its pathogenesis remains unclear.Case presentationA 69-year-old Japanese man developed acute-onset episodic headaches, palpitations, and chest pains. During the episodes, both marked fluctuations in blood pressure (ranging from 40/25 to 300/160 mmHg) and high plasma levels of catecholamines were found simultaneously. Radiological findings indicated a 4-cm left adrenal pheochromocytoma. These episodic symptoms disappeared within 2 weeks with normalization of plasma catecholamine levels. Two months later, the patient underwent adrenalectomy. Microscopic examinations revealed pheocromocytoma with a large central area of coagulative necrosis. The necrotic material was immunohistochemically positive for chromogranin A. Granulation tissue was adjacent to the necrotic area, accompanied by numerous hemosiderin-laden macrophages and histiocytes with vascular proliferation. Viable tumor cells, detected along the periphery of the tumor, demonstrated pyknosis, and the Ki-67 labeling index was 2 % in the hot spot. No embolus or thrombus formation was found in the resected specimen harboring the whole tumor. The Pheochromocytoma of the Adrenal gland Scaled Score was 2 out of 20. The patient’s postoperative course was unremarkable for > 7 years.ConclusionsPresumed causal factors for the extensive necrosis of adrenal pheochromocytoma in previously reported cases include hemorrhage into the tumor, hypotension induced by a phentolamine administration, embolic infarction, high intracapsular pressure due to malignant growth of the tumor, and catecholamine-induced vasoconstriction. In the present case, histopathological and clinical findings suggest that under conditions of chronic ischemia due to catecholamine-induced vasoconstriction, an acute infarction occurred after sudden attacks of alternating hypertension and hypotension. Over the subsequent 2 weeks, repetitive massive release of catecholamines from the infarcts into circulation likely accelerated infarction progression by causing repeated attacks of alternating hypertension and hypotension and resulted in the large necrosis. This case highlights the need for physicians to consider acute spontaneous tumor infarction accompanying episodic catecholamine crisis as a rare but severe complication of pheochromocytoma.

BackgroundsThe association between cigarette smoking and hypertension is controversial. The aim of this study is to investigate the association between smoking and incident hypertension.MethodsThis is a post-hoc five-year follow-up study in a general Japanese population. Logistic regressions were performed using incident hypertension as an outcome and smoking status as an independent predictor adjusting for sex, age, body mass index (BMI), total cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides, fasting plasma glucose (FPG), drinking status, and diabetes in 1,297 subjects without hypertension at baseline.ResultsThe incidence of hypertension was 16.9% vs. 27.6% (smokers vs. nonsmokers, P = 0.01) in men and 0.0% vs. 16.9% (smokers vs. nonsmokers, P = 0.03) in women. The odds ratio (OR) (95% confidence interval (CI)) of incident hypertension was 0.38 (0.19 - 0.76) (P = 0.006) for smokers at baseline, 0.33 (0.16 - 0.68) (P = 0.003) for continuing smokers, and 2.11 (0.33 - 13.45) (P = 0.4) for ex-smokers. Age (OR = 1.52, P < 0.0001), BMI (OR = 1.46, P < 0.0001), and FPG (OR = 1.23, P = 0.007) were other independent predictors of incident hypertension.ConclusionsSmoking was a possible significant negative predictor of incident hypertension in a general Japanese population.

BackgroundGraves’ disease is an autoimmune thyroid disorder characterized by hyperthyroidism, and patients exhibit thyroid-stimulating hormone receptor antibody. The major methods of measuring circulating thyroid-stimulating hormone receptor antibody include the thyroid-stimulating hormone-binding inhibitory immunoglobulin assays. Although the diagnostic accuracy of these assays has been improved, a minority of patients with Graves’ disease test negative even on second-generation and third-generation thyroid-stimulating hormone-binding inhibitory immunoglobulins. We report a rare case of a thyroid-stimulating hormone-binding inhibitory immunoglobulin-positive patient with Graves’ disease who showed rapid lowering of thyroid-stimulating hormone-binding inhibitory immunoglobulin levels following administration of the anti-thyroid drug thiamazole, but still experienced Graves’ hyperthyroidism.Case presentationA 45-year-old Japanese man presented with severe hyperthyroidism (serum free triiodothyronine >25.0 pg/mL; reference range 1.7 to 3.7 pg/mL) and tested weakly positive for thyroid-stimulating hormone-binding inhibitory immunoglobulins on second-generation tests (2.1 IU/L; reference range <1.0 IU/L). Within 9 months of treatment with oral thiamazole (30 mg/day), his thyroid-stimulating hormone-binding inhibitory immunoglobulin titers had normalized, but he experienced sustained hyperthyroidism for more than 8 years, requiring 15 mg/day of thiamazole to correct. During that period, he tested negative on all first-generation, second-generation, and third-generation thyroid-stimulating hormone-binding inhibitory immunoglobulin assays, but thyroid scintigraphy revealed diffuse and increased uptake, and thyroid ultrasound and color flow Doppler imaging showed typical findings of Graves’ hyperthyroidism.ConclusionsThe possible explanations for serial changes in the thyroid-stimulating hormone-binding inhibitory immunoglobulin results in our patient include the presence of thyroid-stimulating hormone receptor antibody, which is bioactive but less reactive on thyroid-stimulating hormone-binding inhibitory immunoglobulin assays, or the effect of reduced levels of circulating thyroid-stimulating hormone receptor antibody upon improvement of thyroid autoimmunity with thiamazole treatment. Physicians should keep in mind that patients with Graves’ disease may show thyroid-stimulating hormone-binding inhibitory immunoglobulin assay results that do not reflect the severity of Graves’ disease or indicate the outcome of the disease, and that active Graves’ disease may persist even after negative results on thyroid-stimulating hormone-binding inhibitory immunoglobulin assays. Timely performance of thyroid function tests in combination with sensitive imaging tests, including thyroid ultrasound and scintigraphy, are necessary to evaluate the severity of Graves’ disease and treatment efficacy.