The response of luteinizing hormone to a single injection of synthetic LRH was established in 6 women and 7 men following an intramuscular dose of 0.2mg or 0.1mg. Significant increases of serum LH were observed in 30 min. Pretreatment with metyrapone for one day (4.5 g/sugject injection of synthetic LRH (0.1 MG/SUBJECT). Seven women, 21-48 years of age who were treated with prednisolone for a least 11/2 months were examined for responsiveness of the anterior pituitary to a single injection of synthetic LRH (0.2 MG). The secretion of LH was markedly suppressed and maximal serum levels of LH WERE OBSERVED 90 MIN FOLLOWING LRH injection.
Dynamics of insulin and glucagon secretion were investigated by using a new model of spontaneous diabetes rats produced by the repetition of selective breeding in our laboratories. The perfusion experiments of the pancreas showed that the early phase of insulin secretion to continuous stimulation with glucose was specifically impaired, although the response of the early phase to arginine was preserved. The glucose-induced insulin secretion in the nineth generation (F8) which had a more remarkably impaired glucose tolerance was more reduced than in the sixth generation (F5). No significant difference of glucagon secretion in response to arginine or norepinephrine was noted between the diabetes rats and control ones. The present data indicate that the defective insulin secretion is a primary derangement in a diabetic state of the spontaneous diabetes rat. This defect in the early phase of glucose-induced insulin secretion suggests the specific impairment of the recognition of glucose by the pancreatic beta-cells. The spontaneous diabetes rats are very useful as a model of disease for investigating pathophysiology of non-insulin dependent diabetes mellitus.
It is almost generally accepted that an acute-phase ACTH response induced by interleukin (IL)-1 is mediated principally by CRH release from the hypothalamus. However, the precise cellular site of action of IL-1 in activating the CRH neuronal system remains to be determined. Two likely candidates comprise the paraventricular nucleus (PVN) where CRH neuronal cell bodies are located, and the median eminence (ME) where their nerve endings are terminated. Therefore, in this study we performed a comparative perfusion of the ME and the PVN with increasing concentrations of recombinant human IL-1β utilizing the push-pull perfusion technique in freely moving rats. We measured the plasma ACTH and ME and PVN levels of CRH, and also of AVP, because AVP, another secretagogue of ACTH, has its cell body in the PVN and axon terminals partly in the ME. In control groups, the ME or the PVN was perfused with artificial cerebrospinal fluid between 12:00 and 15:00 h, and perfusates and blood samples were collected every 20 min. In the other groups, either the ME or the PVN was perfused with three increasing concentrations (0.1, 1.0, and 10 nM) of recombinant human IL-1β dissolved in artificial cerebrospinal fluid only between 13:00 and 14:00 h with all the other procedures run in the same way as in the controls. In the control perfusions, the hypothalamic release of CRH and AVP and the plasma ACTH did not change significantly during the entire period of observation. In the ME perfusion with IL-1β, 1.0 and 10 nM, but not 0.1 nM, of the cytokine significantly and dose-dependently stimulated CRH and AVP secretions in the ME and the plasma ACTH. ACTH responses during the PVN perfusion with IL-1β were similar to those during the ME perfusion, except that at the PVN the lowest concentration (0.1 nM) of the cytokine was already effective in stimulating ACTH secretion. These in vivo data suggest that IL-1β may act on both the ME and the PVN to stimulate CRH and,’ thereby, ACTH secretions. The secretory response of hypothalamic AVP to IL-1β, which was similar to that of CRH, suggests that not only CRH but also AVP may mediate the IL-1β stimulation of ACTH secretion.
OBJECTIVE To evaluate the effect of gastric emptying on postprandial insulinrequirement in insulin-dependent diabetes mellitus (IDDM) patients with and without gastroparesis. RESEARCH DESIGN AND METHODS Postprandial insulin requirement and gastric emptying were simultaneously evaluated in five IDDM patients with gastroparesis and in six control IDDM patients without gastroparesis. Postprandial insulin requirement after test-meal intake was assessed by measuring the insulin infusion rate during a 4-h feedback control with an artificial endocrine pancreas device (Biostator, Life Science Instruments, Miles, Elkhart, IN). Gastric solid and liquid emptyings were evaluated during the Biostator study by measuring the disappearance rate of 99mTc in the stomach and in the time course of plasma acetaminophen concentration, respectively. RESULTS Total insulin requirement during the first 120 min after the test-meal intake was significantly lower in the gastroparetic patients than in the control patients. The gastroparetic patients showed no apparent postprandial peak for insulin infusion rate during the 4-h study, although the peak rate was observed within 120 min after the test-meal intake in the control patients. The disappearance of 99mTc in the stomach was significantly slower, and plasma acetaminophen concentrations were significantlylower in the gastroparetic patients compared with those in the control patients, respectively. CONCLUSIONS The results suggest that IDDM patients with gastroparesis, accompanied by impaired solid and liquid emptying, have an altered postprandial insulin requirement.
We describe a case with unilateral chorea associated with thyrotoxicosis. A 23-year-old female with no family history of neurological diseases acutely developed choreic movements of the left extremities during gross thyrotoxicosis. CT scan and MRI study demonstrated no abnormality. Single-photon emission CT with technetium Tc 99m-labeled hexamethylpropyle neamine oxime revealed normal cerebral perfusion. Although the choreic movements were partially improved by dopamine antagonist, they persisted for two months until successful treatment of the thyrotoxicosis finally abolished these movements. Increased sensitivity of dopamine receptors may be responsible for persistent choreic movements in thyrotoxicosis.
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