Differential effects of a dopaminergic drug (piribedil) on pituitary hormone release in normal men and women

Marinis, Laura De; Mancini, Antonio; Calabrò, F; Massari, Marco; Torlontano, Massimo; Barbarino, A.

doi:10.1530/acta.0.1040385

Cited by 12 publications

(7 citation statements)

References 16 publications

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“…The intra-assay and interassay coefficients of variation ranged from 2.5 to 3.9% and from 5.8 to 8.5%, respectively. Plasma concentra tions of estradiol, progesterone and testosterone were measured by RIA, as previously described [13,14]. All samples from a given study were measured in the same assay.…”

Section: Methodsmentioning

confidence: 99%

Effects of Sex and Age on Pyridostigmine Potentiation of Growth Hormone-Releasing Hormone-Induced Growth Hormone Release

et al. 1992

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Previous studies have shown that pyridostigmine (PD) is capable of increasing the growth hormone (GH) response to GH-releasing hormone (GHRH) in young healthy subjects. In order to investigate the influence of age and sex on the PD potentiation of GHRH-induced GH release, we have studied the GH response to GHRH (50 µg i.v.) 1 h after oral administration of placebo or PD (60 mg) in 8 young healthy men (aged 19-28 years) and 8 age-matched young women (aged 18-25 years) during the follicular phase of the menstrual cycle, as well as in 8 postmenopausal women (aged 57-62 years) and 8 age-matched elderly men (aged 56-64 years). In the same subjects the effect of PD alone (60 mg p.o.) was also studied. Furthermore, in 6 postmenopausal women and 6 elderly men, the effect of a 30-mg PD oral dose on GH secretion and GH response to GHRH was evaluated with a similar protocol. The GH responses (mean ± SE) to GHRH + placebo were similar in young men (peak 20.1 ± 2 ng/ml, AUC 1,250 ± 113 ng/ml/min) and women (peak 29.3 ± 2.3 ng/ml, AUC 1,769 ± 305 ng/ml/min). PD 60 mg was capable of significantly increasing the GH response to GHRH in young men (peak 43.5 ± 5.1 ng/ml, AUC 3,734 ± 472 ng/ml/min, p < 0.005) but not in women (peak 39 ± 2.3 ng/ml, AUC 2,479 ± 205 ng/ml/min). The GH responses to GHRH + placebo were also similar in postmenopausal women (peak 6.2 ± 0.7 ng/ml, AUC 540 ± 80 ng/ml/min) and age-matched men (peak 11.3 ± 0.6 ng/ml, AUC 763 ± 73 ng/ml/min) although these responses were significantly decreased when compared to those observed in young individuals. PD 60 mg administration induced a significant increase in GH response to GHRH both in postmenopausal women (peak 27 ± 3.6 ng/ml, AUC 2,224 ± 251 ng/ml/min, p < 0.001) and elderly men (peak 49.7 ± 2.4 ng/ml, AUC 4,557 ± 263 ng/ml/min, p < 0.001). The GH increment, however, was greater in elderly men than in postmenopausal women (p < 0.005). In young men, elderly men and postmenopausal women, PD 60 mg potentiated the action of GHRH rather than merely being additive. A similar effect was observed when a 30-mg PD dose was preadministered in elderly men and women. Our data clearly demonstrate a marked influence of age and sex on the PD potentiation of the GHRH-stimulated GH secretion. PD significantly potentiated GH responses to GHRH in young men, elderly men and postmenopausal women but not in young women.

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Section: Methodsmentioning

confidence: 99%

Effects of Sex and Age on Pyridostigmine Potentiation of Growth Hormone-Releasing Hormone-Induced Growth Hormone Release

et al. 1992

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“…Considering the dopaminergic activity of Piribedil, 10 the lack of PRL inhibition may be due to the low dose used. 14 The GH response is more complex. In normal subjects, there is a different sex response; in women the response seems to be related to the administered dose 14 ; that is, high doses of Piribedil give a GH release less than that obtained by low dose of the drug; there an inverse relationship between stimulus and response.…”

Section: Resultsmentioning

confidence: 99%

“…14 The GH response is more complex. In normal subjects, there is a different sex response; in women the response seems to be related to the administered dose 14 ; that is, high doses of Piribedil give a GH release less than that obtained by low dose of the drug; there an inverse relationship between stimulus and response. In our study we have shown a greater GH response in normal subjects than in migraine patients, as if in the normals the drug dose was lower.…”

Section: Resultsmentioning

confidence: 99%

Piribedil Test in Migraine: Neruoendocrinological Aspects

Bussone¹,

Frediani²,

Lamperti³

et al. 1986

Headache

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SYNOPSIS Piribedil is a direct central dopamine receptor agonist drug, clinically useful in the diagnosis of migraine. It mayalso be used in the study of migraine pathogenesis, through evaluating dopaminergic “tone”.The observed effects of Piribedil on GH and PRL release, in this study, indicate the existence of dopaminereceptor hypersensitivity in migraine patients. Furthermore our data suggest also the involvement ofnoradrenergic systems in migraine pathogenesis. Estrogen levels do not influence these neuroendocrinologicalresponses to Piribedil, even though the Piribedil test in these female migraine patients was clinically positive (andtherefore diagnostically useful) only during the perimenstrual phase.

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“…Plasma concentrations of estradiol, progesterone, testosterone and cortisol were measured using RIA as previously described (7,8). All samples from a given study were measured in the same assay for each hormone.…”

Section: Methodsmentioning

confidence: 99%

“…In the same subjects, peripherally injected CRH (100 \g=m\g)significantly inhibited the GH response to GHRH (GH peaks 8.1 \m=+-\0.6\g=m\g/l in men, p<0.005 and 9.9\m=+-\0.7\g=m\g/l in women, p<0.005). In an attempt to clarify the mechanism of the CRH action, we have studied the effect of enhanced cholinergic tone induced by pyridostigmine on the CRH inhibition of the GH response to GHRH in a group of six normal men and six normal women.…”

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confidence: 87%

Activation of cholinergic tone by pyridostigmine reverses the inhibitory effect of corticotropin-releasing hormone on the growth hormone-releasing hormone-induced growth hormone secretion

Corsello¹,

Tofani

Casa

et al. 1992

Acta Endocrinologica

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Previous studies have shown that corticotropin-releasing hormone (CRH) is capable of inhibiting growth hormone (GH) secretion in response to GH-releasing hormone (GHRH). In an attempt to clarify the mechanism of the CRH action, we have studied the effect of enhanced cholinergic tone induced by pyridostigmine on the CRH inhibition of the GH response to GHRH in a group of six normal men and six normal women. All subjects presented a normal GH response to 50 \g=m\g iv GHRH administration (mean peak\m=+-\semplasma GH levels 20\m=+-\2.9\g=m\g/lin men and 28.9\m=+-\2.9\g=m\g/lin women) with a further significant increase after pyridostigmine pretreatment (60mg orally given 60 min before GHRH) in men (GH peaks 43.1\m=+-\6.9\g=m\g/l, p<0.005) but not in women (GH peaks 39.2\m=+-\3.0 \g=m\g/l). In the same subjects, peripherally injected CRH (100 \g=m\g)significantly inhibited the GH response to GHRH (GH peaks 8.1 \m=+-\0.6\g=m\g/l in men, p<0.005 and 9.9\m=+-\0.7\g=m\g/l in women, p<0.005). Pyridostigmine (60 mg) given orally at the same time of CRH administration (60 min before GHRH) reversed the CRH inhibition of GHRH-induced GH secretion (GH peaks 35.3 \m=+-\8.2\g=m\g/lin men and 35\m=+-\3.3 \g=m\g/l in women) with a response not significantly different to that seen in the pyridostigmine plus GHRH test. Our data confirm that pyridostigmine is capable of potentiating the GHRH-induced GH release in normal male but not female subjects. In addition, our studies show that the potentiating action of pyridostigmine on the GHRH-induced GH secretion prevails on the inhibiting effect of CRH when the two drugs are given together 1 h before GHRH injection. Both CRH and pyridostigmine could exert their action by modifying, in opposite ways, somatostatin release from the hypothalamus. A Barbarino, Via Diano Marina 9/11, 1-00168 Rome, ItalyWe have recently demonstrated that, in man, corticotropin releasing hormone (CRH) administration is capable of inhibiting the growth hormone releasing hormone (GHRH)-induced growth hormone (GH) secretion (1).These observations confirmed previous studies show¬ ing that, in the rat, intracerebroventricular injection of CRH prevented the stimulatory action of exogenously administered GHRH. The same studies have suggested that the inhibitory action of CRH can involve an increased release of endogenous somatostatin (2-5).However, the precise mechanism by which CRH inhibits the GHRH-induced GH secretion is open to speculation, since it is not known whether CRH action on somatostatinergic neurons is mediated by some neurotransmitters.To examine whether CRH inhibits GHRH-induced GH release by altering the cholinergic system, we have studied the effects of pyridostigmine administration on the CRH-induced inhibition of GH secretion.Since our previous studies (6) have demonstrated the existence of a gender difference in the pyridostigmine potentiation of GHRH-induced GH release, we have studied the effect of pyridostigmine in a group of normal male subjects and a separate group of normal female subjects. ...

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Differential effects of a dopaminergic drug (piribedil) on pituitary hormone release in normal men and women

Cited by 12 publications

References 16 publications

Effects of Sex and Age on Pyridostigmine Potentiation of Growth Hormone-Releasing Hormone-Induced Growth Hormone Release

Effects of Sex and Age on Pyridostigmine Potentiation of Growth Hormone-Releasing Hormone-Induced Growth Hormone Release

Piribedil Test in Migraine: Neruoendocrinological Aspects

Activation of cholinergic tone by pyridostigmine reverses the inhibitory effect of corticotropin-releasing hormone on the growth hormone-releasing hormone-induced growth hormone secretion

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