A new improvement of the sensitivity and specificity of radioimmunoassay for thyroliberin. Application to biological samples

Grouselle, Dominique; Tixier‐Vidal, A.; Pradelles, P.

doi:10.1016/0143-4179(82)90063-4

Cited by 30 publications

(7 citation statements)

References 19 publications

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“…TRH RIA and TRH-OH enzyme immunoassays were performed as previously described (18) thanks to the kind cooperation of D. Grouselle (College de France, Paris). The Ps4 RIA system, using synthetic Ps4 as a standard and [ 125 I-Tyr°] Ps4 as a radioligand, has been described (2).…”

Section: Antisera and Ria Proceduresmentioning

confidence: 99%

Processing of Thyrotropin-Releasing Hormone (TRH) Prohormone in the Rat Olfactory Bulb Generates Novel TRH-Related Peptides*

Bulant

Jc²,

Delfour³

et al. 1990

Endocrinology

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Based on the deduced amino acid sequence of rat TRH prohormone (pro-TRH), proteolytic processing of this polyprotein precursor is expected to produce, beside TRH, several other novel peptides. These peptides should correspond to connecting segments flanking the repeated TRH progenitor sequence and to various C- and/or N-terminally extended forms of TRH. The profile of the endogenous products of the TRH system was studied in rat brain using multiple RIAs coupled to molecular sieve filtration and HPLC separations. In extracts from the rat hypothalamus, TRH and two pro-TRH-connecting peptides, prepro-TRH-(160-169) and prepro-TRH-(178-199) were detected in molar ratios corresponding to those expected for a nearly complete processing of the prohormone molecule. In the olfactory bulb, pro-TRH is processed differently, since peptides containing TRH at their N-termini, [pGlu172] prepro-TRH-(172-199) and [pGlu154]prepro-TRH-(154-169), were found to be major end products along with prepro-TRH-(160-169) and prepro-TRH-(178-199). The dissimilarity in tissue content suggests that differential processing of TRH precursor by various enzymatic pathways may act as a regulating mechanism for TRH and TRH-related activities. The cellular localization of C-terminally extended forms of TRH in rat olfactory bulb was examined by the indirect immunoperoxidase method, using antisera directed against prepro-TRH-(160-169) and pre-pro-TRH-(178-199). Cell bodies and nerve fibers were detected in the glomerular and external plexiform layers of the main olfactory bulb. The presence of extended forms of TRH in interneurons and middle tufted cells of the main olfactory bulb suggests that in light of the recent biological properties described for prepro-TRH-(160-169), these peptides may act as neuromodulators for olfactory epithelium inputs or neurotransmitters within more rostrally located olfactory areas in the forebrain.

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Section: Antisera and Ria Proceduresmentioning

confidence: 99%

Processing of Thyrotropin-Releasing Hormone (TRH) Prohormone in the Rat Olfactory Bulb Generates Novel TRH-Related Peptides*

Bulant

Jc²,

Delfour³

et al. 1990

Endocrinology

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“…After centrifugation (2,000 x g for 20 min) the supernatant was evaporated and the pellet was kept for protein and TRH measurement. TRH concentrations were estimated by RIA as previously described: the radioimmunoassay was performed using an immune serum anti-TRH with high specificity at a final dilution of 1:150,000 and monoiodo ([125I] His 2 )TRH purified by TLC as a tracer (Grouselle et al 1982). The sensitivity of the method was around 4fmoles.…”

Section: Measurement Of Serotonin and Trh Contentmentioning

confidence: 99%

Hypothalamic control of prolactin release in the rainbow trout,Salmo gairdneri: in vitro studies

Gonnet¹,

Barret²,

Grouselle³

et al. 1989

Fish Physiol Biochem

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Hypothalamic control of prolactin (PRL) release in immature rainbow troutSalmo gairdneri was investigated using anin vitro perifusion system of the rostral pars distalis. Hypothalamic extract of trout induced a dose-dependent stimulation of PRL release. A similar effect was observed when infusing the medium from a 24h static incubation of the hypothalamus. Extracts from different control tissues (muscle, liver, gut) did not changein vitro release, thus confirming the specificity of this stimulatory effect. Hypothalamic extract from adult male rat, known to contain PRL release inhibiting factors, stimulatedin vitro PRL secretion in rainbow trout. This suggests that PRL cells are predominantly influenced by PRL releasing factors. Measurement of TRH and serotonin content in trout hypothalamus indicated consistent physiological levels of these two factors. HPLC studies of hypothalamic extract showed that immunoreactive - TRH eluted at the same place as labelled TRH standard. Moreover, pizotifen, a serotonin antagonist, partially inhibited the stimulation observed with trout hypothalamic extract. These results suggest that, in immature rainbow trout, PRL release is under stimulatory hypothalamic control and that serotonin and probably TRH play a major role in this control.

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“…The tissue slices were perifused at constant flow rate (8.4 ml/hr) and constant temperature (370C) with Krebs-Ringer's bicarbonate buffer (pH 7.4). The effluent was collected in 10-min fractions of 1.4 ml and the concentrations of Ps4 and TRH were determined by radioimmunoassay in duplicate, as described (15,22). To induce depolarization, KCl (70 mM) pulses of 15-min duration were administered, the concentration of NaCl being proportionally lowered to keep a constant osmolarity.…”

mentioning

confidence: 99%

Processing of thyrotropin-releasing hormone prohormone (pro-TRH) generates a biologically active peptide, prepro-TRH-(160-169), which regulates TRH-induced thyrotropin secretion.

Bulant

Roussel

Astier

et al. 1990

Proc. Natl. Acad. Sci. U.S.A.

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Rat thyrotropin-releasing hormone (TRH) prohormone contains five copies of the TRH progenitor sequence Gln-His-Pro-Gly linked together by connecting sequences whose biological activity is unknown. Both the predicted connecting peptide prepro-TRH-(160-169) (Ps4) and TRH are predominant storage forms of TRH precursor-related peptides in the hypothalamus. To determine whether Ps4 is co-released with TRH, rat median eminence slices were perifused in vitro. Infusion of depolarizing concentrations of KCI induced stimulation of release of Ps4-and TRH-like immunoreactivity. The possible effect of Ps4 on thyrotropin release was investigated in vitro using quartered anterior pituitaries. Infusion of Ps4 alone had no effect on thyrotropin secretion but potentiated TRH-induced thyrotropin release in a dosedependent manner. In addition, the occurrence of specific binding sites for '251-labeled Tyr-Ps4 in the distal lobe of the pituitary was demonstrated by binding analysis and autoradiographic localization. These findings indicate that these two peptides that arise from a single multifunctional precursor, the TRH prohormone, act in a coordinate manner on the same target cells to promote hormonal secretion. These data suggest that differential processing of the TRH prohormone may have the potential to modulate the biological activity of TRH.

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A new improvement of the sensitivity and specificity of radioimmunoassay for thyroliberin. Application to biological samples

Cited by 30 publications

References 19 publications

Processing of Thyrotropin-Releasing Hormone (TRH) Prohormone in the Rat Olfactory Bulb Generates Novel TRH-Related Peptides*

Processing of Thyrotropin-Releasing Hormone (TRH) Prohormone in the Rat Olfactory Bulb Generates Novel TRH-Related Peptides*

Hypothalamic control of prolactin release in the rainbow trout,Salmo gairdneri: in vitro studies

Processing of thyrotropin-releasing hormone prohormone (pro-TRH) generates a biologically active peptide, prepro-TRH-(160-169), which regulates TRH-induced thyrotropin secretion.

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