Thyrotropin-releasing hormone stimulates nitric oxide release from GH3 cells.

Constitutive nitric oxide synthase (NOS) is expressed in the rat adenohypophysis but the mechanisms regulating its activity at the cellular level remain to be elucidated. The effect of TRH on nitric oxide release from GH3 cells was studied by means of reverse-phase HPLC to measure NO-2 and NO-3 concentrations in the incubation medium, and by polarography using electrodes specific for NO. Medium NO-2 concentrations in the incubation medium were dependent on the incubation time, and were further increased by sodium nitroprusside (SNP) or high potassium. NO-3 was detectable only in the presence of 100 microM SNP. Addition of L-arginine increased medium NO-2 concentrations. Diamino-hydroxypyrimidine decreased medium NO-2 concentrations, which were restored by the addition of (6R)-5, 6, 7, 8-tetrahydro-L-biopterin (THB). TRH elicited dose-related increases in medium NO-2 concentrations and in nitric oxide-specific currents, which were abolished by Nomega-nitro-L-arginine methyl ester. TRH failed to increase medium NO-2 concentrations in cells loaded with an intracellular Ca2+-chelating agent. The findings suggest that mobilization of intracellular Ca2+ by TRH stimulation activates Ca2+-dependent NOS in GH3 cells.

Antihypertensive effect of insulin via nitric oxide production in the Zucker diabetic fatty rat, an animal model for non-insulin-dependent diabetes mellitus.

It has been reported that insulin treatment improves hypertension in patients with diabetes mellitus. The mechanisms of the antihypertensive effect of insulin, however, remain to be fully elucidated. In the present study, we investigated a possible involvement of nitric oxide (NO) in insulin-induced reduction of blood pressure using the Zucker diabetic fatty (ZDF) rat, an animal model of non-insulin-dependent diabetes mellitus. The animals were divided into three groups and treated for 4 weeks with daily subcutaneous injections of insulin (25U/kg body weight) with or without oral administration of l-nitro-arginine methyl ester (L-NAME, 50mg/kg/day body weight as drinking water), an inhibitor of NO synthase (NOS). Saline solution was injected subcutaneously in the control groups. During the experimental period, body weight gain was greater in the insulin-treated groups than in the control groups whereas water intake was considerably decreased in the insulin-treated groups. Insulin treatment resulted in a decrease in plasma glucose and blood pressure, and an increase in both NO metabolites (NOx) in the plasma and NOS activity in the aorta tissue. L-NAME treatment blunted not only the antihypertensive effect of insulin but also the changes in NOx and NOS activity. These findings suggest that insulin reduces blood pressure in the ZDF rat by stimulating NOS activation and NO production.

Endogenous nitric oxide inhibits growth hormone secretion through cyclic guanosine monophosphate-dependent mechanisms in GH3 cells.

Constitutive nitric oxide synthase (NOS) is expressed in rat adenohypophysis and clonal GH3 cells. The mechanisms of action of nitric oxide (NO) to inhibit hormone secretion and the possible role of (6R)-5, 6, 7, 8-tetrahydro-L-biopterin (THB) in the action of endogenous NO were studied in GH3 cells. Inhibiting NOS with N(G)-nitro-L-arginine or trapping NO with oxyhemoglobin enhanced both the basal and TRH-stimulated rat GH release. Sodium nitroprusside did not further decrease either the basal or the TRH-stimulated GH secretion, suggesting that endogenous NO exerted the maximal inhibitory effect. Inhibition of de novo synthesis of THB increased GH secretion. A cyclic guanosine-monophosphate (cGMP) antagonist did not increase the basal GH secretion but enhanced TRH-induced GH release. These findings suggest that endogenous NO plays an inhibitory role on basal GH release and TRH-stimulated hormone release from GH3 cells in an autocrine or paracrine fashion, at least partly, through a cGMP-dependent pathway. It is also suggested that endogenous THB plays a role in NO production and subsequent inhibition of hormone secretion in GH3 cells.

[Treatment with bolus methylprednisolone for pure red cell aplasia after ABO incompatible bone marrow transplantation in a patient with chronic myelocytic leukemia].

Pure red cell aplasia (PRCA) was found in a male patient with chronic myelocytic leukemia after major ABO incompatible bone marrow transplantation (BMT). He had blood group O, and received BMT from an HLA identical sibling (blood group A). Erythrocyte-depleted marrow was transplanted. Methotrexate for short time and cyclosporine (CyA) were used for graft versus host disease (GVHD) prophylaxis. Engraftment of neutrophils and platelets were observed on day 14 and 22, respectively. The Ph1 chromosome disappeared on day 133. However engraftment of erythrocytes was not observed on day + 280. Bone marrow puncture revealed depletion of erythrocyte precursors. Anti-A isoagglutinin was persisted. There was no evidence of acute or chronic GVHD. Administration of prednisolone, discontinuance of CyA and subcutaneous infusion of recombinant human erythropoietin failed to improve PRCA. Bolus methylprednisolone (m-PSL) therapy started on day 284 resulted in rapid increase in reticulocyte counts within 6 days, which was followed by normal hemoglobin concentrations. We conclude that bolus m-PSL may be one treatment for PRCA after BMT.

Presence of beta-citryl-L-glutamic acid in the lens: its possible role in the differentiation of lens epithelial cells into fiber cells.

The beta-CG concentration in the chicken brain was high during embryonic development and decreased rapidly to a lower level close to hatching, while the concentration in the eyeball which was also high during the embryonic life retained a fairly high level after hatching. The distribution of beta-CG in the bovine eye was determined. About 95% of total beta-CG content in the whole eye was localized in the lens. However, the distribution of beta-CG in the eye varied depending on species. beta-CG was exclusively localized in the lens in the eyes of fish and mammals, but distributed in both lens and retina in frogs. The molecule was localized in the retina rather than the lens in the chicken eye, although the concentrations was extremely low compared to those in the mammalian, amphibian and fish eyes. It was found that beta-CG is present ubiquitously in the lens or retina in various species. The distribution of beta-CG in the bovine lens was determined in the three cortex regions and nucleus. beta-CG was present at the highest concentration in the equatorial cortex, at a moderate concentration in the posterior and anterior cortex, and at the lowest concentration in the nucleus. Similar distribution patterns were also found in the rabbit and rat lens. When embryonic chick lens epithelial cells were cultured in the presence of fetal calf serum, the cells elongated, differentiated into fiber cells and formed lentoid bodies. The cells of lentoid bodies were stained strongly by the anti-beta-CG antibody, while cells around the structures were not. In addition, the beta-CG content in the lenses from the galactose cataractous rat decreased to about 20-30% of that in the normal lens. These findings suggest that beta-CG may play a role in the differentiation of epithelial cells into fiber cells.

[Clinical and laboratory correspondence to outpatients with the extreme value of C-reactive protein].

INTRODUCTION: It is the policy of Tenri Hospital to notify the patient promptly whenever an extreme laboratory data value is detected. We investigated the utility of forwarding clinical and laboratory correspondence to outpatients with extreme value of C-reactive protein (CRP). MATERIAL AND METHOD: Sixty-eight outpatients with CRP levels more than 20 mg/dl detected during 1986 were studied. CRP was measured by turbidometric method, and a sample with CRP level more than 15 mg/dl was diluted with CRP negative serum (CRP level less than 0.2 mg/dl) and was reanalyzed. RESULTS: Fifty-two of 68 patients (76%) had infectious diseases as the causal disease of high CRP, and eight (12%) had other diseases. In the remaining (12%) the causes were unknown. In most patients the causal diseases were diagnosed within one or two days, but diagnosis required more than 4 days in those with acute pyelonephritis, meningitis, liver abscess or renal abscess, as these diseases were diagnosed after the examination of urine or cerebrospinal fluid, or after ultrasonography. Thirty-seven of 58 patients (64%) who had appointments with their physician on the day of the laboratory examination were admitted the same day, and two of 10 patients (20%) who had appointments on the following day were admitted on that day. Seventeen of 25 patients (68%) with urea-N levels more than 30 mg/dl, cholinesterase levels less than 0.7 delta pH and albumin levels less than 3.5 g/dl required more than 15 days to recover, while 29 of 32 patients (91%) with only 2 or fewer of these laboratory values required less than 14 days. CONCLUSION: The prompt notification of extreme CRP value is an important aspect of medical care. The examination of urine and cerebrospinal fluid and ultrasonography are necessary screening techniques accompanying examination of blood and plain chest X-ray. Urea-N, cholinesterase and albumin values should be determined at the same time as CRP value to assess prognosis.

[Study of prognostic factors and estimation of prognosis in patients with fungemia].

INTRODUCTION: The estimation of prognosis is necessary in the treatment of fungemia because of its high mortality rate. We studied prognostic factors and estimated prognosis by scoring clinical and laboratory findings in 41 patients with fungemia treated at Tenri Hospital between 1976 and 1990. RESULTS: Although the mortality rate was low (33%) in 18 patients in whom the route of infection had been an intravenous catheter or the urinary tract, it was high (91%) in 23 patients with other or unknown route of infection. The risk of death was high in patients with disseminated intravascular coagulopathy (DIC), shock (systolic blood pressure > or = 90 mmHg), malnutrition (cholinesterase < 0.05 delta pH and albumin < or = 3.0 g/dl), renal failure (urea-N > or = 30 mg/dl and creatinine > or = 3.0 mg/dl), neutropenia (neutrophils < or = 500/microliters) or advanced age (age > or = 60 years old). Application scoring system taking into account of the presence or absence of DIC or shock, the degree of malnutrition, renal failure and neutropenia, and age (20 possible points) in 36 patients revealed that the scores of the 23 patients who died significantly different from those of the 13 survivors; score was less than 6 in every survivor (100%), while it was more than 6 in twenty-two (96%) of the patients who died. Seven of 10 patients with persistent fungal infection had greater than 15. CONCLUSION: The prognosis of patients with fungemia is adversely influenced by the presence of DIC, shock, malnutrition, renal failure, neutropenia and advanced age, and the scoring of these clinical and laboratory findings is useful in the estimation of prognosis and detection of persistent fungal infection in these patients.