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E Hermand

Publications and source records attributed to E Hermand.

31 records · Page 2Linked to original sources
PubMed1975

[Hypothalamic mechanism of the antiovulatory action of sulpiride].

The antiovulatory effect of sulpiride is mediated via inhibition of the LH-RH release: when given during 10 days in guinea pigs, sulpiride is able to promote an increase of LH-RH immunoreactive substance in anterior hypothalamic and suprachiasmatic neurons. This storage probably related with inhibition of LH-RH release, is permitted by catecholamines, since metatyrosine administration prevent this sulpiride effect. On the other hand, when administered to hamsters sulpiride is able to promote stimulation of hypothalamic catecholaminergic neurons of tubero infundibular and anterior periventricularis nuclei. The hypothalamic aminergic action upon sulpiride antiovulatory effect is discussed.

Animals↗
PubMedDate not supplied

Paracrine factors in adult rat testis gonadotrophin control of opioids and LHRH like peptide.

A paracrine regulation involves agents which are produced by one cell type and act on an other one within an organ. In rodent testis, local control mechanisms modulate the actions of the gonadotrophins according to local requirements. Two groups of peptides-opioids and testicular LHRH are defined as paracrine factors and in vivo they are both modified by HCG. In vitro, after HCG exposure, we first localized an opioid like material in Sertoli cells cytoplasma by immunohistochemistry. This material is detected in freeze dried homologous culture media using a dot immunobinding technique. With a longer HCG exposure, an LHRH like material is then visualized in the basal compartment of the Sertoli cells and it is detected in freeze dried homologous culture media by the same technical procedure than for opioid material. By adding synthetic enkephalins to culture medium, we obtain the same results as with the endogenous opioid material, excreted after HCG addition. If naloxone a potent opiate antagonist, is added to the culture medium previously to HCG or enkephalins, the Sertoli cells cytoplasma are no more immunoreactives with the anti-enkephalin serum and no LHRH material is neither visualized by immunohistochemical technique neither detected in culture media. We conclude that testicular opioids, synthetized by the Leydig cells and which have specific Sertoli cells receptors are one Leydig-Sertoli paracrine communication factor. One way of response to their receptor fixation is the synthesis and excretion by Sertoli cells of testicular LHRH. This one is known to act on Leydig cells via specific receptors and it is one Sertoli-Leydig cells paracrine communication factor.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗