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001-es BibID:	BIBFORM073589
Első szerző:	Bodnár Ibolya
Cím:	Stress- as well as suckling-induced prolactin release is blocked by a structural analogue of the putative hypophysiotrophic prolactin-releasing factor, salsolinol / I. Bodnar, B. Mravec, L. Kubovcakova, E. B. Toth, F. Fulop, M. I. K. Fekete, R. Kvetnansky, G. M. Nagy
Dátum:	2004
ISSN:	0953-8194
Megjegyzések:	Prolactin is secreted from the anterior lobe of the pituitary gland in response both to suckling and to stress. We recently observed that 1?methyl?6,7?dihydroxy?1,2,3,4?tetrahydroisoquinoline (salsolinol), produced in the neurointermediate lobe of the pituitary gland, as well as in the medial basal hypothalamus, can selectively release prolactin from the anterior pituitary. Therefore, it has been proposed that salsolinol is a putative endogenous prolactin?releasing factor (PRF). Here, we report that one structural analogue of salsolinol, 1?methyl?3,4?dihydroisoquinoline (1MeDIQ), can block salsolinol?induced release of prolactin, but does not affect prolactin release in response to thyrotropin releasing hormone (TRH), ??methyl?p?tyrosine (?MpT) (an inhibitor of tyrosine hydroxylase), domperidone (a D2 dopamine receptor antagonist), or 5?hydroxytryptophan (5?HTP), a precursor of serotonin). 1MeDIQ profoundly inhibited suckling?, immobilization?, as well as formalin?stress induced prolactin release without any influence on corticosterone secretion. The 1MeDIQ?induced reduction in prolactin response to immobilization stress was dose?dependent. These results suggest that salsolinol can play a pivotal role in the regulation of prolactin release induced by either physiological (suckling) or environmental (stress) stimuli.
Tárgyszavak:	Orvostudományok Gyógyszerészeti tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Journal of Neuroendocrinology 16 : 3 (2004), p. 208-213. -
További szerzők:	Mravec, B. Kubovcakova, L. Tóth E. Béla (1960-) (orvos) Fülöp Ferenc Fekete I. K. Márton Kvetnansky, R. Nagy György M.
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001-es BibID:	BIBFORM073591
Első szerző:	Homicskó Krisztián Gy.
Cím:	Binding site of salsolinol : its properties in different regions of the brain and the pituitary gland of the rat / Krisztián Gy. Homicskó, István Kertész, Balázs Radnai, Béla E. Tóth, Géza Tóth, Ferenc Fülöp, Márton I. K. Fekete, György M. Nagy
Dátum:	2003
ISSN:	0197-0186
Megjegyzések:	It has been recently shown that salsolinol (SAL) is present in the hypothalamic neuroendocrine dopaminergic (NEDA) system and appears to be a selective and potent stimulator of prolactin (PRL) secretion in the rat. Furthermore, the lack of interference of SAL with -spiperone binding in the striatum and the anterior lobe (AL) of the pituitary gland has been also demonstrated. These data clearly indicate that SAL does not act at the dopamine (DA) D2 receptors, and suggest that SAL supposedly has a binding site through which the secretion of PRL may be affected. Therefore, binding of -SAL to different regions of the central nervous system (CNS) has been investigated. Specific and saturable binding has been detected in the striatum, cortex, median eminence and in the hypothalamus as well as in the AL and the neuro-intermediate lobe (NIL) of the pituitary gland. KD values of the bindings were in the nanomolar range in all tissue tested. -SAL displacing activity of several agonists and antagonists of known DA receptors have also been tested. It has been found that DA and in a lesser extent, apomorphine could displace -SAL, but other DA receptor specific ligands have not been able to affect it. Furthermore, several pharmacologically active compounds, selected on the basis of their influence on DA synthesis, transport mechanisms and signal transduction, have also been tested. Neither mazindol (a selective DA transporter inhibitor) nor clonidine (an ?2-adrenoreceptor agonist) could alter SAL binding. At the same time, l-dopa, carbidopa, benserazide and ?-methyldopa were able to displace -SAL. The possible changes in SAL binding due to physiological and pharmacological stimuli, like suckling stimulus and reserpine pretreatment (that blocks vesicular monoamine transport in DA terminals), respectively, have also been investigated. In the NIL of the pituitary gland and in the median eminence of the hypothalamus the binding decreased following 10 min of suckling stimulus compared to the binding detected in the same tissues obtained from mothers separated from their pups for 4 h and not allowed to be suckled. At the same time, there were no changes in the binding at the AL and striatum. Following reserpine pretreatment that has completely prevented PRL releasing effect of SAL, the binding was significantly augmented. These results support our assumption that SAL should have specific binding sites through which it can affect PRL secretion. Furthermore, it clearly suggests that it may regulate DAergic neurotransmission of NEDA neurons by an altered intracellular or intraterminal synthesis and/or distribution of hypophysiotropic DA.
Tárgyszavak:	Orvostudományok Gyógyszerészeti tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Neurochemistry International 42 : 1 (2003), p. 19-26. -
További szerzők:	Kertész István (1966-) (vegyész) Radnai Balázs Tóth E. Béla (1960-) (orvos) Tóth Géza Fülöp Ferenc Fekete I. K. Márton Nagy György M.
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001-es BibID:	BIBFORM073595
Első szerző:	Tóth E. Béla (orvos)
Cím:	Physiological role of salsolinol : its hypophysiotrophic function in the regulation of pituitary prolactin secretion / Béla E. Tóth, Ibolya Bodnár, Krisztián G. Homicskó, Ferenc Fülöp, Márton I. K. Fekete, György M. Nagy
Dátum:	2002
ISSN:	0892-0362
Megjegyzések:	We have recently observed that 1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline (salsolinol) produced by hypothalamic neurons can selectively release prolactin from the anterior lobe (AL) of the pituitary gland. Moreover, high affinity binding sites for SAL have been detected in areas, like median eminence (ME) and the neuro-intermediate lobe (NIL) that are known terminal fields of the tuberoinfundibular DAergic (TIDA) and tuberohypophysial (THDA)/periventricular (PHDA) DAergic systems of the hypothalamus, respectively. However, the in situ biosynthesis and the mechanism of action of SAL are still enigmatic, these observations clearly suggest that sites other than the AL might be targets of SAL action. Based on our recent observations it may be relevant to postulate that an "autosynaptocrine" regulatory mechanism functioning at the level of the DAergic terminals localized in both the ME and NIL, may play a role in the hypophyseotrophic regulation of PRL secretion. Furthermore, SAL may be a key player in these processes. The complete and precise mapping of these intra-terminal mechanisms should help us to understand the tonic DAerg regulation of PRL secretion. Moreover, it may also give insight into the role of pre-synaptic processes that most likely have distinct and significant functional as well as pathological roles in other brain areas using DAergic neurotransmission, like striatonigral and mesolimbic systems.
Tárgyszavak:	Orvostudományok Gyógyszerészeti tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Neurotoxicology and Teratology 24 : 5 (2002), p. 655-666. -
További szerzők:	Bodnár Ibolya Homicskó Krisztián Gy. Fülöp Ferenc Fekete I. K. Márton Nagy György M.
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001-es BibID:	BIBFORM031973
Első szerző:	Tóth E. Béla (orvos)
Cím:	Salsolinol is putative endogenous Neuro-intermediate lobe prolactin-releasing factor / Tóth B. E., Homicskó K., Radnai B., Maruyama W., DeMaria J. E., Vecsernyés M., Fekete M. I. K., Fülöp F., Naoi M., Freeman M. E., Nagy G. M.
Dátum:	2001
ISSN:	0953-8194
Megjegyzések:	The isolation and identification of a prolactin-releasing factor (PRF) from the neuro-intermediate lobe of the pituitary gland has been pursued for over a decade. Using high-pressure liquid chromatography with electrochemical detection (HPLC-ECD) and gas chromatography/mass spectrometry (GC/MS) (R)-salsolinol (SAL) (a dopamine-related stereo-specific tetrahydroisoquinoline) was found to be present in neuro-intermediate lobe as well as median eminence extracts of male, intact-, and ovariectomized female rats. Moreover, analysis of SAL concentrations in neuro-intermediate lobe revealed parallel increases with plasma prolactin in lactating rats exposed to a brief (10 min) suckling stimulus following 4-h separation. SAL appears to be a selective and potent stimulator of prolactin secretion in vivo and it was without effect on the secretion of other pituitary hormones. We have also found that SAL can elevate prolactin release, although to a lesser extent, in pituitary cell cultures as well as in hypophysectomized rats bearing anterior lobe transplants under the kidney capsule. Lack of interference of SAL with [3H]-spiperone binding to AP homogenates indicates that SAL does not act at the dopamine D2 receptor. Moreover, [3H]-SAL binds specifically to homogenate of AL as well as neuro-intermediate lobe obtained from lactating rats. Taken together, our data clearly suggest that SAL is synthesized in situ and this compound can play a role in the regulation of pituitary prolactin secretion.
Tárgyszavak:	Orvostudományok Gyógyszerészeti tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Journal Of Neuroendocrinology 13 : 12 (2001), p. 1042-1050. -
További szerzők:	Homicskó Krisztián Gy. Radnai Balázs Maruyama W. DeMaria, Jamie E. Vecsernyés Miklós (1959-) (gyógyszertechnológus, endokrinológus) Fekete I. K. Márton Fülöp Ferenc Naoi, M. Freeman, Marc E. Nagy György M.
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