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Biomedical subjects

C Rougeot

Publications and source records attributed to C Rougeot.

62 records · Page 4Linked to original sources
PubMed1983

Selective decrease in immunoreactive somatostatin in rat intermediate pituitary lobe after stalk section.

Immunoreactive somatostatin is present in the intermediate pituitary lobe of the rat and, to a lesser extent, in the posterior lobe. Section of the pituitary stalk results in a marked (80%) decrease in somatostatin in the intermediate pituitary lobe, but no change in the peptide levels in the posterior lobe. These results indicate that a substantial part of intermediate lobe somatostatin is located in nerve fibers originated in the brain.

Animals↗
PubMed1982

Use of an anti-human leukocyte interferon monoclonal antibody for the purification and radioimmunoassay of human alpha interferon.

Mouse monoclonal antibody directed against human leukocyte alpha interferon (IFN-alpha) was coupled to Sepharose and used as an immunoadsorbent to purify human IFN-alpha. Leukocyte and lymphoblastoid (Namalva) IFNs were retained by the immunoadsorbent with a specificity of 80 to 100% and 40 to 60%, respectively. Human IFN-beta or -gamma and mouse IFN were not retained. The purified IFN-alpha retained its antiviral and anticellular properties as well as its ability to induce the 2-5A synthetase in human cells with a specific activity similar to that of the crude IFN. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of radioactively labeled IFN showed that it consisted of several proteins in the molecular weight range of 17,000 to 27,000. 125I-labeled IFN-alpha with a high specific activity (2,000 Ci/mmol) was used in a radioimmunoassay for the titration of IFN-alpha.

Antibodies, Monoclonal↗
PubMed1980

Tissue levels and displacement of in vivo labelled beta-adrenergic receptors by FM 24, an irreversible or slowly dissociable beta-blocker.

FM 24 [1-(2-exo-bicyclo[3,3,1]hept-2-ylphenoxy)-3-[(1-methylethyl)amino] 2-propanol hydrochloride] and propranolol were compared in mice with respect to their ability to displace in vivo 125I-hydroxybenzylpindolol which is selectively associated with beta-adrenergic receptor binding sites. After a simultaneous i.v. injection of the beta-blockers and 125I-hydroxybenzylpindolol propranolol was more active than FM 24. At an equiblocking dose i.e. a dose which inhibits by 80% the binding of 125I-hydroxybenzylpindolol, FM 24 was still effective after 6 h (40% inhibition in the brain and the heart, 60% in the lung) contrary to propranolol. After oral administration (2 mg/kg), 40% inhibition by FM 24 still persisted at 24 h in the heart whereas no effect of propranolol was detectable at 18 h. As the kinetics of [3H]FM 24 and [3H]propranolol after oral and i.v. administration are not very different we confirmed that the prolonged beta-blocking action of FM 24 was related to a tight irreversible binding to beta-receptors rather than to pharmacokinetic properties of this drug.

Adrenergic beta-Antagonists↗
PubMedDate not supplied

Influence of endogenous growth hormone-releasing factor (GRF) on the secretion of GH during the perinatal period in the rat.

Passive immunization of pregnant rats with a specific antiserum to rat GRF (GRF-AS) is followed by a decrease in fetal serum GH on the 19th day of gestation. A significant reduction in serum GH is still observed in older fetuses and newborn rats. Pituitary GH content increases in 19- and 20-day-old fetuses after GRF-AS administration to their mothers. These results suggest that endogenous fetal hypothalamic GRF (or placenta GRF) play a physiological role in the secretion of pituitary GH as early as the 19th day of fetal life and may be responsible for the peak of GH release that occurs in fetuses at the end of gestation.

Aging↗
PubMedDate not supplied

Chromatographic identification of Met- and Leu-enkephalin in the human fetal spinal cord.

Using the indirect immunofluorescence method, enkephalin-like immunoreactivity was visualized on human fetus spinal cord sections (gestational age from 17 to 25 weeks). Immunolabeled varicose fibers and terminal-like structures were seen through the whole length fetal spinal cord principally in the dorsal gray, in the intermediate gray and in the lateral funiculus. A few enkephalin-like immunoreactive cells were sometimes detected in the intermediate gray. Finally, some immunolabeled fibers were also visible in the ventral spinal cord especially proximate to the motor nuclei areas at the sacral level. Fetal spinal cord tissue extracts from the cervical thoracic and lumbosacral region were chromatographically analyzed using high pressure liquid chromatography in combination with the radioimmunoassay. This biochemical analysis indicates that authentic pentapeptides Met- and Leu-enkephalin may account for a large part (more than 90%) of the enkephalin-like immunoreactivity detected in the fetal spinal cord investigated. Taken together our results suggest that the biosynthetic processing of Met- and Leu-enkephalin in this tissue might be functional early before birth.

Chromatography, High Pressure Liquid↗
PubMedDate not supplied

Basal and PAF-, interleukin 1-, ether stress-induced hypothalamic pituitary adrenal secretion of conscious rat: modulation by PAF antagonists.

We have previously shown that exogenous (1 to 5 nmol i.c.v.) PAF induces a rapid increase in plasma ACTH and beta endorphin followed by an increase in plasma corticosterone in conscious rats. The stimulatory action of PAF on the secretion of hypothalamic-pituitary-adrenal (HPA) axis products is mediated at least partly by stimulating hypothalamic CRF release. In addition rat hypothalamic membranes have two populations of specific PAF binding sites. In order to clarify the mode of PAF action on the stress-related hormones, we have now investigated the effect of two PAF antagonists, BN 50739 and RP 52770, on basal and PAF-induced ACTH and corticosterone secretion by conscious rats and on PAF specific binding to rat hypothalamic membranes. The role of PAF as a mediator of neuroendocrine secretion in response to acute stress was examined by determining the effect of PAF antagonists on ether-stress inducing HPA activity. We have also investigated their effect on IL 1-induced HPA activity. The ability of BN 50739 and RP 52770 to displace 3H PAF from its hypothalamic binding sites was correlated with their ability to alter basal hormone secretion and to counteract the PAF-stimulated secretion of HPA axis hormones in vivo (P less than 0.05 by ANOVA). Pretreatment with BN 50739. (50 nmol i.c.v.) did not alter ACTH response to a 1 min ether exposure or to IL1 beta injection (2 nmol i.c.v.). In contrast, RP 52770 (55 nmol i.c.v.) significantly inhibited the ether stress-induced ACTH and corticosterone production by 50% (P less than 0.05). In parallel, pretreatment with RP 52770 (55 nmol i.c.v.) caused a significant inhibition of IL1 beta-induced ACTH secretion. These results suggest that PAF acts, in vivo, on ACTH and corticosterone secretion, through a centrally mediated CRF dependent mechanism involving PAF receptor sites. Additionally, the data also indicate that PAF could have a central role in mediating basal and stress-induced ACTH secretion and that IL 1-induced HPA secretion may be mediated at least in part through the production of PAF.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

ACTH/beta-endorphins and ACTH/cortisol ratios as early biological markers in HIV infection.

Three groups of male homosexuals: AIDS (n = 19), HIV seropositive (n = 15), and seronegative partners of seropositive subjects (n = 15), were compared to a heterosexual seronegative control group (n = 13). Twice daily evaluations (8 A.M. and 5 P.M.) of plasma levels of beta-endorphin, ACTH, and cortisol were done by radioimmunoassay. Seropositive subjects and their seronegative partners showed similar levels of neurohormones: 1. An elevation in the ACTH/beta-endorphin ratio in the plasma, (C = 0.69 +/- 0.84, AIDS = 0.44 +/- 0.32, S+ = 0.42 +/- 0.28, and S- = 0.42 +/- 0.5); 2. A loss of normal relationship of the coupling ACTH/total cortisol, (C = 0.00035 +/- 0.00028, AIDS = 0.00042 +/- 0.0034, S+ = 0.00074 +/- 0.00068, and S- = 0.00072 +/- 0.0008. Neuroendocrinological disorders have been observed in HIV-infected subjects and in their seronegative partners. These could be related to their sexual behavior, as well as to the HIV infection. If this last hypothesis is confirmed, the ACTH/beta-endorphin and ACTH/cortisol ratios may be seen as possible early signs of HIV infection.

Adolescent↗