176
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Biscans B, Bertrand J. Modelling of a continuous flow electrophoresis cell computation procedure design. Comput Chem Eng 1988. [DOI: 10.1016/0098-1354(88)85023-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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177
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Caron M, Cherqui G, Wicek D, Capeau J, Bertrand J, Picard J. Effect of protein kinase C activation and depletion on insulin stimulation of glycogen synthesis in cultured hepatoma cells. EXPERIENTIA 1988; 44:34-7. [PMID: 3280335 DOI: 10.1007/bf01960235] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Insulin stimulation of glycogen synthesis was nearly abolished in hepatoma cells shortly treated with 4 beta-phorbol 12 beta-myristate, 13 alpha-acetate (protein kinase C activation) but remained unmodified in cells chronically treated with the phorbol ester (protein kinase C depletion). Thus, although exogenous activation of protein kinase C results in an inhibition of insulin action, protein kinase C depletion has no influence on this process. The results suggest that, in hepatoma cells, no endogenous activation of protein kinase C may occur in response to the signal triggered by insulin.
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178
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Forest MG, David M, David L, Chatelain PG, François R, Bertrand J. Undescended testis: comparison of two protocols of treatment with human chorionic gonadotropin. Effect on testicular descent and hormonal response. HORMONE RESEARCH 1988; 30:198-205; discussion 205-6. [PMID: 2907898 DOI: 10.1159/000181060] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A randomized study of two protocols of human chorionic gonadotropin (hCG) treatment was performed in 183 prepubertal boys between 7 months and 12 years of age: protocol I, in which the boys were given 7 injections of 1,500 IU every other day, and protocol II consisting of 4 injections of 100 IU/kg at 4- to 5-day intervals. In both protocols, by the end of the test, testosterone had risen significantly to values within the normal adult male range. However, the amplitude of the rise was slightly but significantly lower using protocol II (4.08 +/- 2.07 ng/ml) than protocol I (5.16 +/- 2.73 ng/ml). It would thus appear that repetition of the hCG injection at intervals of less than 4 days is unnecessary, and that a total stimulation period of 2-3 weeks is sufficient. Although not correlated with testosterone levels, the success rates for treatment were similar in both protocols and comparable to rates reported in the literature.
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179
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Gardette J, Margelin D, Maziere JC, Bertrand J, Picard J. Effect of dibutyryl cyclic AMP and theophylline on lipoprotein lipase secretion by human monocyte-derived macrophages. FEBS Lett 1987; 225:178-82. [PMID: 2826237 DOI: 10.1016/0014-5793(87)81153-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The effect of dibutyryl cyclic AMP and theophylline on lipoprotein lipase secretion was investigated after a 24 h pretreatment of human monocyte-derived macrophages. Both the effectors decreased in a dose-dependent manner the enzyme activity recovered in the culture medium. The decrease in lipoprotein lipase activity appeared to be related to reduced enzyme synthesis without apparent modification of its stability and half-life and was conversely associated with an increase of lysosomal acid hydrolase activities. This effect was reversible on removal of the nucleotide. The present findings suggest that cyclic AMP may play a role in lipoprotein lipase expression in human macrophages and therefore may participate in the regulation of lipoprotein uptake by these cells, which are strongly implicated in the atherogenic process.
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180
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Furet Y, Metman EH, Breteau M, Bertrand J. [Hepatitis due to nonsteroidal anti-inflammatory agents]. ANNALES DE GASTROENTEROLOGIE ET D'HEPATOLOGIE 1987; 23:367-74. [PMID: 3324927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The extended prescription of non-steroidal anti-inflammatory drugs in medical practice involve numerous adverse effects. Among them, hepatic injuries, rather uncommon, are very diverse with regard to clinical type and evolution scheme, according to the derivatives used. Salicylates, when taken at high doses, increase serum transaminases, mostly without overt clinical symptoms. Phenylbutazone is obviously hepatotoxic: it induces cytolytic hepatitis, in some cases with fatal issue. Among the indole derivatives, indometacine was involved, especially in children; mixed hepatitis have been noted during sulindac therapy, mostly with favourable outcome. In the group of propionic acid derivatives, ibuprofen, pirprofen and naproxen have been implicated in hepatitis of various types; ibufenac and benoxaprofen were quickly retired after occasioning several deaths. Concerning others non-steroidal anti-inflammatory drugs, some cases have been reported with piroxicam and diclofenac. Hepatotoxicity mechanisms are often unknown; they appear different according to each drug. Besides, the rheumatic disease under treatment and pharmacokinetic particularities (sulindac, diclofenac) might be important in this view. Monitoring of serum hepatic-enzyme concentrations seems recommended for patients receiving non-steroidal anti-inflammatory for long time therapy.
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181
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Thivolet CH, Durand A, Chatelain P, Bertrand J. Human islet cell autoantibodies specifically bind cloned rat islet cells. DIABETES RESEARCH (EDINBURGH, SCOTLAND) 1987; 6:71-6. [PMID: 3322634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Sera from newly diagnosed type I (insulin dependent) diabetic patients and control subjects were tested by indirect immunofluorescence on a particular subclone of RINm5F cells for the presence of cytoplasmic antibodies. Cell cultures after biochemical fixation and frozen sections of cell sheets obtained after incubating confluent monolayers with dispase were used alternatively as substrate. Eight out of ten ICA positive sera previously tested on frozen sections of human pancreas bind RIN cells when fixed with acetone-ethanol whereas no staining was obtained after treating the cells with paraformaldehyde or glutaraldehyde. Four normal sera did not bind RIN cells under these conditions. Alternatively, frozen sections of cell sheets appeared to be a more sensitive substrate as all ICA positive sera tested reacted with cell cytoplasm. In addition, an immunoradiometric assay was developed using microtitre plate wells coated with Nonidet P40 solubilized RIN antigens. Coated wells were incubated with ICA positive and ICA negative diabetic sera along with sera from normal individuals. Antigen antibody complexes were detected by the binding of 125I-Protein A. A good correlation was found between binding values and results obtained by indirect immunofluorescence on frozen sections of human pancreas. Although this study indicates that RIN cells express a specific cytoplasmic antigen to which ICA positive sera bind, more information is required concerning the exact nature of this antigen before such assay can be reliably used for the detection of ICA.
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182
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Jordan D, Sabbagh I, Guillaumot P, Veisseire M, Bertrand J, Cohen H. Thyroid-hypophyso-hypothalamic axis of the genetically hypoprolactinemic rats (IPL nude rats). Neuroendocrinology 1987; 46:194-8. [PMID: 3116445 DOI: 10.1159/000124819] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
In order to evaluate thyrotropin function in the genetically hypoprolactinemic rat, (IPL nude), we measured by radioimmunoassay TRH hypothalamic content, pituitary TSH content and serum TSH, T3, T4, both in IPL nude and control rats at various times over the 24-hour period. Compared to normal rats, the hypothalamic TRH content in the IPL nude rat showed similar variations during the day, whereas a slight increase was observed during the night characterized by a significant difference at 20.00 h. Pituitary weight and TSH content were doubled in IPL nude rats; however, when expressed as micrograms TSH/micrograms protein or DNA, a significant increase was found only at 17.00 and 20.00 h. Serum TSH and total serum T3, T4 depicted similar variations although they were minute but nonetheless significant modifications, i.e. an increase of TSH at 17.00 and 23.00 h and a decrease of T4 at 11.00 h. However, only FT4 concentrations (and not-FT3) were slightly but significantly decreased in IPL rats over the experimental times. In conclusion, the slight increase in hypothalamic TRH and pituitary TSH contents and the absence of main associated variations of serum TSH, T3 and T4 do not lend support to the hypothesis that TRH could be the cause of the hypoprolactinemia of these rats. On the contrary, the observed thyrotropin axis variations might be rather interpreted as the consequence of it.
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183
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Boiron M, Arhan P, Dorval ED, Rouleau P, Metman EH, Bertrand J, Thouvenot J. [Propagation of the gastric peristalsis in normal subjects and duodenal ulcer patients]. GASTROENTEROLOGIE CLINIQUE ET BIOLOGIQUE 1987; 11:312-8. [PMID: 3582886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The velocities of gastric peristaltic waves were measured on fluorographic series made in normal subjects and patients with duodenal ulcer. After an overnight fast, the subjects drank 250 ml of barium suspension. Sequential radiograms were taken every 2 s during 30 s after two pyloric ejections. Peristaltic waves were located and their displacements measured with an Apple Graphic Tablet. Wave progression diagrams and velocity histograms were drawn for each subject. The velocities were calculated every 2 s. A "spread index" Ip was determined for each subject, characterizing the irregularity of propagation. Mean frequency and mean velocity were greater in duodenal ulcer patients (3.6 c/min; 3.7 mm/s) than in normal subjects (2.9 c/min; 2.4 mm/s; p less than 0.001). Nevertheless, no significant difference was found between proximal or midcorpus and antral velocities, in ulcer patients as well as in normal subjects, contrarily to classical data. However, the velocities were not uniform along the stomach. The contractions spread unevenly and displayed transient slopes. The irregularities of propagation were more pronounced in normal subjects, ranging from 0 to 14 mm/s with 28 p. 100 of velocities less than 1 mm/s, then in ulcer patients (0 to 13 mm/s with 12 p. 100 of low velocities). The spread index Ip was greater in normal (ranged from 0.54 to 2.62) than in ulcer patients (ranged from 0.16 to 0.48; p less than 0.001). This study showed that the propagation velocity of the peristaltic waves and its regularity were different in normal subjects and in duodenal ulcer patients.
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184
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De Cock KM, Awadh S, Raja RS, Wankya BM, Jupp RA, Slavin B, Arap Siongok TK, Rees PH, Bertrand J, Lucas SB. Chronic splenomegaly in Nairobi, Kenya. II. Portal hypertension. Trans R Soc Trop Med Hyg 1987; 81:107-10. [PMID: 3127951 DOI: 10.1016/0035-9203(87)90297-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Eighty-five patients with chronic splenomegaly and proven oesophageal varices were studied at Kenyatta National Hospital, Nairobi. The major defined groups were hepatosplenic schistosomiasis (24%), cirrhosis (20%) and portal vein occlusion (11%). Hyper-reactive malarial splenomegaly (tropical splenomegaly syndrome) was considered as the cause of oesophageal varices in only one patient. In 26% of cases liver biopsy was non-diagnostic and the extrahepatic portal vein was demonstrated radiologically to be patent. Such patients were thought to be suffering from idiopathic portal hypertension, not previously described elsewhere in Africa. Hepatitis B surface antigen was detected in 12% of controls and in 58% of patients with cirrhosis (p less than 0.001). Some serological marker of previous hepatitis B virus infection was present in 92% of patients with cirrhosis and in 79% of controls. Kamba patients from Machakos and Kitui Districts were significantly more prevalent than expected among these 85 cases of portal hypertension.
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185
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Furet Y, Metmann EH, Breteau M, Bertrand J. [Review of the literature apropos of a case of hepatic involvement in treatment with azathioprine (Imurel)]. JOURNAL DE TOXICOLOGIE CLINIQUE ET EXPERIMENTALE 1987; 7:51-6. [PMID: 3598920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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186
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Duparc J, Bertrand M, Bertrand J. [Asthma and asthmatiform symptoms in the dental office. Certain explanations, therapeutic and prophylactic advice]. L' INFORMATION DENTAIRE 1986; 68:4479-83. [PMID: 2951328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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187
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de Peretti E, Forest MG, Loras B, Morel Y, David M, François R, Bertrand J. Usefulness of plasma pregnenolone sulfate in testing pituitary-adrenal function in children. ACTA ENDOCRINOLOGICA. SUPPLEMENTUM 1986; 279:259-63. [PMID: 3022522 DOI: 10.1530/acta.0.112s259] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
In normal subjects, plasma pregnenolone sulfate (PS) levels high at birth, decreased during the first year of life in relation to the pattern of involution of the fetal adrenal zone. Thereafter, PS levels, in contrast with those of DHAS, did not show the abrupt rise characteristic of the adrenarche, but increased very progressively till adulthood. The response of PS to various provocative tests of adrenal and pituitary function (ACTH and Metyrapone stimulation, dexamethasone suppression), has been established in normal subjects. The measurement of plasma PS levels in basal conditions as well as in response to dynamic tests was very useful in the diagnosis of various adrenal and pituitary diseases in children.
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188
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Fewell RG, Allison RT, Bertrand J, Cowell DC, Farr AD, Jarvis JD, Rogers DJ. Medical laboratory sciences: a look forward. MEDICAL LABORATORY SCIENCES 1986; 43:307-13. [PMID: 3657412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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189
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Baulieu F, Baulieu JL, Dorval E, Metman E, Bertrand J, Itti R. Scintigraphy in duodeno-gastric reflux: a new method of quantification. Nucl Med Commun 1986; 7:747-54. [PMID: 3808494 DOI: 10.1097/00006231-198610000-00005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A prospective study is undertaken in order to demonstrate the ability of scintigraphy with a non compartmental analysis to quantitate the duodeno-gastric reflux. 24 patients have been examined, sitting in front of a gamma camera: 12 with an endoscopically proved reflux and 12 normal subjects or volunteers. About 15 min after an injection of 148 to 222 MBq 99Tcm-IDA they were given a meal labelled with 37 MBq 113Inm-DTPA. Images were recorded for 2 h. Equal size gastric and duodenal ROIs were selected over the duodenum and stomach, avoiding overlap with neighbouring organs. The reflux index based upon the occupancy principle is calculated from the gastric and duodenal curves. It is the ratio between the gastric and duodenal ROI IDA fluxes. The value of the reflux index is 3 +/- 1.8% in normal subjects and 45 +/- 33% in pathological cases. Our method, which does not require intubation, quantitatively evaluates biliary reflux independently of injected dose and hepatic or gallbladder function.
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190
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Margulies A, Metman EH, Girard JJ, Dorval ED, Bertrand J. [Severe constipation indicative of pseudohypoparathyroidism and resolved after normalization of the blood calcium]. ANNALES DE GASTROENTEROLOGIE ET D'HEPATOLOGIE 1986; 22:271-2. [PMID: 3777869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Hypocalcemia does not appear among the endocrine and metabolic causes of constipation. The work-up of a severe constipation has disclosed a pseudo-hypoparathyroidism according to the clinical picture described by Albright, associating signs of hypo-parathyroidism, a characteristic dysmorphic syndrome, mental deficiency and normal PTH dosages. The resolve of the constipation along with the return to a normal calcemia suggests that hypocalcemia should be added to the long list of endocrine and metabolic causes of constipation.
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191
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Biscans B, Bertrand J, Sanchez V. Fonctionnement hydrodynamique d'une cellule d'électrophorèse: Elements de calcul. CAN J CHEM ENG 1986. [DOI: 10.1002/cjce.5450640503] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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192
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Furet Y, Metman EH, Bertrand J, Breteau M. [Mixed hepatitis due to rifamycin SV. Apropos of a case]. Therapie 1986; 41:405-6. [PMID: 3810533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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193
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Guillaumot P, Sabbagh I, Bertrand J, Cohen H. Prolactin receptor regulation by LH in the rat mammary gland. Biochem Biophys Res Commun 1986; 135:1076-83. [PMID: 3008740 DOI: 10.1016/0006-291x(86)91038-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The aim of this study was to investigate hormonal factors responsible for the huge increase in PRL receptors on the day of estrus in the rat mammary gland. For this purpose, ovariectomized rats were primed with E2 so as to reach a physiological serum concentration of E2 (21.5 +/- 1.2 pg/ml) and high PRL serum values (72.8 +/- 21.9 ng/ml). In these conditions, PRL specific binding and capacity were respectively 22.8 +/- 8.3%/mg protein and 96 +/- 29 fm/mg protein. An injection of either LHRH (500 ng/rat) or LH (60 micrograms LH-RP1/rat) was capable of increasing significantly both PRL specific binding and capacity. Capacity reached the values of 498 +/- 103 and 507 +/- 240 fm/mg protein for LHRH and LH respectively. LHRH action appeared to be mainly mediated through LH secretion, since no difference was found between LHRH and LH. LHRH and LH injections alone were unable to modify PRL binding, suggesting that they only potentiate E2 and PRL action. These results show for the first time that LH is involved in the regulation of PRL receptors in the rat mammary gland.
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194
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Bertrand J, Morel Y, Forest MG. [Hormonal mechanisms of puberty]. LA REVUE DU PRATICIEN 1986; 36:825-32. [PMID: 3518029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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195
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Cohen H, Sabbagh I, Abou-Samra AB, Bertrand J. beta-Endorphin in genetically hypoprolactinemic rat: IPL nude rat. Life Sci 1986; 38:217-24. [PMID: 2934601 DOI: 10.1016/0024-3205(86)90306-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Beta-endorphin has been reported to regulate not only stress- and suckling-induced but also basal prolactin secretion. In the aim to better evaluate the endogenous beta-endorphin-prolactin interrelation, we measured beta-endorphin levels in a new rat strain, genetically hypoprolactinemic and characterized by a total lack of lactation: IPL nude rat. Beta-endorphin was measured using a specific anti-h-beta endorphin in plasma and extracts of anterior and neurointermediate lobes of the pituitary, hypothalamus and brain. Pituitary extracts were also chromatographed on Sephadex G50 column. Results obtained showed that in IPL nude females on diestrus and males, the beta-endorphin contents of the neurointermediate lobe was significantly lower than in normal rats, while the values found in the other organs and plasma were similar. However, elution pattern of the anterior pituitary extract from male rats showed greater immunoactivity eluting as I125 h-beta-endorphin than in normal rat; this was not the case for the female rat. These results are consistent with a differential regulation of beta-endorphin levels of anterior and neurointermediate lobe by catecholamines. Moreover they suggest that PRL secretion was more related to neurointermediate beta-endorphin.
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196
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Cohen H, Sabbagh I, Guillaumot P, Bertrand J. Steroid regulation of gonadotropins in genetically hypoprolactinemic females (IPL nude rats). JOURNAL OF STEROID BIOCHEMISTRY 1986; 24:431-5. [PMID: 3084874 DOI: 10.1016/0022-4731(86)90096-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
IPL nude females present an absence of lactation with hypoprolactinemia. While males present a slight but significant decrease in serum testosterone and gonadotropins, females show normal values of estradiol, progesterone, LH and FSH during all estrus cycle stages. In this work, we observed that the postovariectomy rise of LH and FSH was significantly lower in the IPL nude females. We studied also the effect of acute (1 injection of 25 micrograms/rat E2Bz) or long-term (E2Bz capsule for 8 days) estradiol benzoate (E2Bz) treatment, with or without progesterone injection (5 mg/rat) in ovariectomized (OVX) IPL and normal females. The sensitivity of gonadotropins to E2 negative feedback is decreased in the IPL nude rats, result in agreement with previous reports and which could be linked to both hypoprolactinemia and decreased beta-endorphin observed in the IPL nude rat. The responsiveness of LH to LHRH was also tested in OVX and OVX + E2Bz or OVX + E2B + P treated. In OVX females responsiveness of LH to LHRH was similar in IPL nude to that of normal females. However, LH responsiveness in acute and long-term steroid-treated OVX IPL nude was significantly depressed. Since the mechanism whereby PRL interacts with steroids to modify gonadotropin secretion is still unexplained, IPL nude rat could be a good model to study it.
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197
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Danquechin Dorval E, Metman EH, Bertrand J, Huten N, Bertrand P, Rouleau P. [Effect of ranitidine on gastric emptying of nondegradable solids in duodenal ulcer patients]. GASTROENTEROLOGIE CLINIQUE ET BIOLOGIQUE 1986; 10:89-90. [PMID: 3956917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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198
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Abou Samra AB, Fèvre-Montange M, Loras B, Durand A, Tourniaire J, Bertrand J. Effect of indolamines on beta-endorphin release by rat anterior pituitary cells. Neuroendocrinology 1985; 41:490-3. [PMID: 2934638 DOI: 10.1159/000124224] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The effect of indolamine derivatives on beta-endorphin (beta-end) release has been studied in vitro using rat anterior pituitary cells. Incubation of primary cultures for 2 h with 100 nmol/l of melatonin, serotonin or 5-methoxytryptamine significantly increased the beta-end release in response to 20 nmol/l of ovine corticotropin-releasing factor (oCRF). Incubation of the cultures with 100 nmol/l of L-tryptophan, 5-hydroxy-L-tryptophan, 5-hydroxytryptophol or 5-methoxytryptophol had no effect on basal or CRF-induced beta-end release. The effect of serotonin and melatonin was further tested in a superfusion system of dispersed rat anterior pituitary cells. Superfusion with oCRF (200 nmol/l) for 4 min elicited an immediate rapid increase in beta-end release which lasted 30-40 min. Simultaneous superfusion with melatonin (1 mumol/l) or serotonin (1 mumol/l) significantly increased the effect of oCRF pulses on beta-end release. We conclude that melatonin and serotonin are able to act directly on anterior pituitary cells to potentiate the effect of oCRF on beta-end release.
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199
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Cohen H, Sabbagh I, Guillaumot P, Bertrand J. Increased dopaminergic inhibition of prolactin in the hypoprolactinaemic IPL nude rat. J Endocrinol 1985; 107:325-9. [PMID: 4067488 DOI: 10.1677/joe.0.1070325] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In this study, aimed at investigating whether dopaminergic regulation of prolactin could be implicated in the hypoprolactinaemia observed in the IPL nude rat, dopaminergic inhibition of prolactin was suppressed using a catecholamine synthesis inhibitor alpha-methyltyrosine (MT) and a dopaminergic antagonist sulpiride. Adult male rats (IPL nude and normal) were injected through implanted atrial cannulae with either MT (250 mg/kg) or physiological saline (control). Rats were decapitated 2 h after the injection. Plasma prolactin levels, compared with basal values, increased by 15.6 +/- 1.9 (S.E.M.)- and 5.89 +/- 0.6-fold in IPL nude and normal rats respectively. This difference was highly significant. The pituitary prolactin content was decreased in both groups. In a second experiment, adult male IPL nude or normal rats were injected with either sulpiride (1 mg/kg) or saline and decapitated 2, 4, 8, 12, 14 and 24 h later. Plasma prolactin levels, compared with basal values, were increased in rats injected with sulpiride by 9.2 +/- 1.8 and 3.4 +/- 0.7-fold in IPL nude and normal rats respectively. The pituitary prolactin content was reduced more in IPL nude than in normal sulpiride-injected rats. These data suggest that prolactin secretion, as well as synthesis, is under an increased dopaminergic inhibition in the male IPL nude rat.
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200
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Bertrand J. [A reader's question or language problem: to benefit from an algorithm]. Presse Med 1985; 14:1801. [PMID: 2933664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
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