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Biomedical subjects

B Conte-Devolx

Publications and source records attributed to B Conte-Devolx.

At least 55 records · Page 3Linked to original sources
PubMed1979

[Distribution of thyrotropin releasing hormone (TRH), alpha-melanocyte-stimulating hormone (alpha-MSH) and somatostatin in the skin of the green frog (Rana esculenta)].

High concentrations of Thyrotrophin-Releasing Hormone (TRH) have been found in the dorsal skin of the Frog Rana esculenta, lower levels being measured in the ventral skin. alpha-MSH and somatostatin were undetectable in these tissues. Nor was TRH detected in the blood of these animals. The concentration of somatostatin in the pancreas was similar to that of the hypothalamus and twice or one hundred times higher than in the intestine or stomach respectively.

Animals↗
PubMed1979

Immunoreactive somatostatin in rat hypophysial portal blood.

Somatostatin levels have been determined by RIA in hypophysial portal blood of pentobarbital-anesthetized male rats. In most animals, immunoreactive somatostatin (SRIF) levels were higher in hypophysial portal blood than in systemic blood. In euthyroid rats, the mean level was 158 +/- 27 pg/ml (n = 8); SRIF was undetectable (less than 30 pg/ml) in systemic blood of these rats. It is suggested that endogenous SRIF was not degraded during the collection of stalk blood, since synthetic SRIF is stable when incubated in rat serum during 4 min at 37 c and 2 h at 0 C, i.e. under the conditions the blood was kept during the collection. SRIF in hypophysial portal plasma had the same immunoreactivity with a specific antiserum against SRIF as did synthetic SRIF. Gel filtration of hypophysial portal plasma revealed two immunoreactive peaks, the major one corresponding to synthetic SRIF, the smaller one representing a larger molecular form. Thyroidectomy and excess of T4 did not modify the levels of SRIF in hypophysial portal blood, suggestinc SRIF is stable when incubated in rat serum during 4 min at 37 C and 2 h at 0 C, i.e. under the conditions the blood was kept during the collection. SRIF in hypophysial portal plasma had the same immunoreactivity with a specific antiserum against SRIF as did synthetic SRIF. Gel filtration of hypophysial portal plasma revealed two immunoreactive peaks, the major one corresponding to synthetic SRIF, the smaller one representing a large molecular form. Thyroidectomy and excess of T4 did not modify the levels of SRIF in hypophysial portal blood, suggesting that the feedback of thyroid hormones on TSH secretion does not involve changes in the secretion of SRIF by the hypothalamus.

Animals↗
PubMed1979

[Systematic evaluation of 8 arginine vasopressin and neurophysins plasma levels in 10 patients with oat cells carcinoma of the lung (author's transl)].

Plasma AVP level, neurophysins and osmolality have been measured in 10 patients with oat cell carcinoma of the lung but without any biological signs of syndrome of inappropriate secretion of ADH (SIADH), before and 15 mn after an intravenous injection of Ethanol. No statistically significant difference was noted in the AVP, neurophysins and osmolality values between 10 patients with asymptomatic oat cell carcinoma and control population (10 normal volunteers, 12 patients with non neoplasic lung pathology and 10 patients with different lung carcinoma). We concluded that AVP and neurophysins cannot be considered as a good tumoral marker in the detection of oat cell carcinoma of the lung.

Arginine Vasopressin↗
PubMed1977

[Syndrome of inappropriate secretion of vasopressin. Apropos of 3 cases].

3 cases of inappropriate vasopressin secretion during one case of anaplastic carcinoma of the lung, one case of carcinoma of the prostate with bony metastases and one case of acute intermittent porphyria are presented. The plasma levels of vasopressin, measured by radioimmunoassay were high. Treatment with demeclocycline was attempted in one case. The clearance of free water was positive but the treatment was poorly tolerated by the digestive tract.

Acute Disease↗
PubMed1977

[Simultaneous liberation of vasopressin (ADH) and of neurophysins during nicotine perfusion in man].

Using the radioimmunoassay (R.I.A.) for neurophysins (I.R.N.) described in 1969, we demonstrated a concomitant, rapid release of both A.D.H. and I.R.N. within the first minutes (2') of the i.v. infusion of nicotine in 11 patients with normal neuropituitary function and 1 patient suffering from a Schwartz-Bartter syndrome. There is a close relationship (r : 0,82, p less than 0.001) similar to that described by other authors, between peak levels of A.D.H. and I.R.N. in all the patients. Hence, we proved that our R.I.A. system is influenced by nicotine stimulated neurophysins (N.S.N.). The negative results previously published by two of us in 5 normal men could have been due to the length of the period between the beginning of the test and the first blood sampling (30 mn).

Humans↗
PubMed1977

[Radioimmunoassay for human plasma 8-arginine-vasopressin (author's transl)].

The authors have developed a radioimmunoassay for human plasma vasopressin (AVP) which permits the estimation of antidiuretic hormon (ADH) levels as low as 0,8 pg/ml. The average plasma level of AVP after overnight water restriction was found to be 14,3 pg/ml (sd = 4,4 pg/ml) in normal subjects. They provoked a hypersecretion of ADH by the intravenous injection of 1-2 mg of nicotine. In 11 volunteer normal subjects this stimulation by nicotine provoked ADH hypersecretion which reached a maximum between 2nd and 15th minutes after injection. In 3 cases of diabetes insipidus, nicotine injection did not induce ADH hypersecretion; in 1 case of potomania this response was weak; in 2 cases of syndrome of inappropriate ADH secretion, AVP plasma levels were elevated and the response after nicotine stimulation was exaggerated.

Arginine Vasopressin↗
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

Corticotropin-releasing factor release from in vitro superfused and incubated rat hypothalamus. Effect of potassium, norepinephrine, and dopamine.

We have compared the release of CRF induced by potassium depolarization, noradrenaline or dopamine as monitored either during superfusion of mediobasal hypothalamus or during incubation of whole hypothalamus. The superfusion device was improved in order to prevent gas leakage and to keep constant pO2 and pCO2 in the superfusion chamber. Basal CRF secretion as well as KCl- and norepinephrine-induced CRF release were comparable in superfusion and incubation experiments. Pharmacological investigations suggest that the stimulatory effect of norepinephrine on CRF release is mediated mainly through alpha 1 and alpha 2 adrenergic receptors, and partially through beta receptors.

Animals↗
PubMedDate not supplied

[Callosogenital dysplasia].

A nosological entity, calloso-genital dysplasia, is described from a case of primary amenorrhoea with coloboma and total agenesis of the corpus callosum. Deficiency of the thalamic gonadotropic hormone secretion was elicited, together with normal or moderately elevated prolactinaemia, the significance of which is discussed. Thyrotropic, somatotropic and corticotropic functions were normal. It may be that the hypogonadotropic eunuchoidism of this 24-year old woman with normal olfaction evolved towards panhypopituitarism over a number of years, but in such a malformation that had not changed since birth the thalamic hypophysiotropic dysfunction seems to be fixed and stable. Unless a most unlikely coincidence occurred, the primary amenorrhoea seems to be related to the malformation. Agenesis of the corpus callosum with panhypopituitarism is well known, but this case is original in that the pituitary deficiency is very limited. A comparison with its mirror image, olfacto-genital dysplasia or Kallman's syndrome is tempting, but it remains to be documented anatomically by other cases.

Abnormalities, Multiple↗