Biomedical subjects

P Del Rizzo

Publications and source records attributed to P Del Rizzo.

6 recordsLinked to original sources

PubMed2003

Abnormal 5-HT1D receptor function in cluster headache: a neuroendocrine study with sumatriptan.

The purpose of this study was to assess the sensitivity of 5-HT(1D) receptors in patients with episodic cluster headache using sumatriptan as a pharmacological probe. The drug, a selective 5-HT(1B/1D) agonist, stimulates the secretion of growth hormone and inhibits the release of prolactin, adrenocorticotropic hormone (ACTH) and cortisol. These effects may be used to explore the function of serotonergic systems in vivo. We administered subcutaneous sumatriptan and placebo to 20 patients with cluster headache (10 in the active phase and 10 in the remission period) and to 12 controls. The sumatriptan-induced increase of growth hormone concentrations was significantly (P < 0.05) blunted in patients with active cluster headache. Prolactin and ACTH responses to the drug were significantly (P < 0.05) reduced in patients with cluster headache, both in the active and in the remission period. Our results suggest that cerebral serotonergic functions mediated by 5-HT(1D) receptors are altered in patients with episodic cluster headache.

Adult↗

PubMed2002

Hypothalamic-pituitary-adrenal axis function and cytokine production in multiple sclerosis with or without interferon-beta treatment.

OBJECTIVES: Pro-inflammatory cytokines mediate brain damage in multiple sclerosis (MS); they can also influence the hypothalamic-pituitary-adrenal (HPA) axis function. We evaluated the possible abnormalities of HPA axis function in relapsing-remitting MS (RR-MS). MATERIAL AND METHODS: IFN-gamma, TNF-alpha and IL-6 production by ex-vivo lymphocytes from 10 normal volunteers and 10 RR-MS patients before and during IFN-beta therapy was assessed; pituitary-adrenal function was evaluated by means of CRH and ACTH stimulation tests. RESULTS: In untreated patients the production of IFN-gamma, TNF-alpha, IL-6 was increased, and was significantly decreased by IFN-beta. Neither basal, nor stimulated ACTH, cortisol, DHEA, DHEAs, 17-alpha-OH-progesterone levels differed between controls and RR-MS patients, both before and during treatment. Moreover, no correlation was found between endocrine and immune parameters. CONCLUSION: In MS the HPA axis function seems normal and not influenced by IFN-beta treatment. This result is discussed in relation to the increased production of pro-inflammatory cytokines found in this disease.

Adjuvants, Immunologic↗

PubMed2002

Decreased sensitivity of 5-HT1D receptors in chronic tension-type headache.

OBJECTIVE: To assess the sensitivity of 5-HT1D receptors in chronic tension-type headache using sumatriptan as a pharmacological probe. BACKGROUND: Previous studies have suggested involvement of serotonergic systems in chronic tension-type headache (CTTH), but relevant experimental data are limited. Sumatriptan, a 5-HT1B/1D receptor agonist, stimulates the release of growth hormone (GH) and inhibits the release of ACTH, cortisol, and prolactin. These effects may be used to explore the function of serotonergic systems in vivo. METHODS: We measured GH, ACTH, cortisol and prolactin (PRL) plasma concentrations in 15 patients with chronic tension-type headache and in 18 healthy controls after subcutaneous administration of sumatriptan (6 mg) or placebo. RESULTS: Placebo administration had no effect on hormone concentrations. GH and PRL secretion after sumatriptan administration was significantly (P<0.01 and <0.05) altered in CTTH patients in comparison with controls. CONCLUSION: Our results suggest that cerebral serotonergic functions mediated by 5-HT1D receptors are altered in CTTH.

Adult↗

PubMed2002

Failure of angiotensin II and insulin to stimulate transforming growth factor-beta1. Release from cultured bovine retinal pericytes.

BACKGROUND: Activation of the renin-angiotensin system (RAS) may induce cardiovascular and renal fibrosis in hypertension and diabetes. This fibrogenic effect is mainly mediated by Transforming Growth Factor-B1 (TGF-B1), a multifunctional citokyne released by endothelial, vascular smooth muscle and renal mesangial cells, that is able to increase extracellular matrix deposition. Retinal capillary pericytes have functions similar to those of mesangial cells, including ability to synthesize and release TGF-B1 and produce extracellular matrix. An intraocular RAS was described in the human eye and may produce effects similar to those observed in the heart and kidney, which could be mediated by TGF-B1. In particular, TGF-B1 might be involved in thickening of the capillary basement membrane in diabetic microangiopathy. We therefore aimed at evaluating the possible effects of Angiotensin-II on TGF-B1 secretion by cultured retinal pericytes (BRP). METHODS: BRP cultures were incubated with Angiotensin-II or insulin (known to play a permissive effect on TGF-B1 release from mesangial cells) or Angiotensin-II + insulin at final concentrations of 10-10, 10-8, 10-6, 10-4 mol/L. RESULTS: Baseline TGF-B1 concentrations in the supernatants of pericyte cultures were 6 139 +/- 1 919 pg/mL/106 cells; no changes of TGF-B1 concentrations resulted from adding increasing amounts of Ang II, insulin or both. CONCLUSIONS: Though confirming that cultured bovine retinal pericytes spontaneously release TGF-B1, Angiotensin-II did not produce any stimulatory effects of in our experimental system

Analysis of Variance↗

PubMed2001

Neuroendocrine effects of subcutaneous sumatriptan in patients with migraine.

We evaluated the sensitivity of 5-HT1D receptors in patients with migraine using sumatriptan as a pharmacological probe. The drug inhibits the release of ACTH, cortisol and prolactin and this effect may be used to explore the function of serotoninergic systems in vivo. We administered sumatriptan (6 mg sc) and placebo to 15 migraineurs, during the headache-free period, and to 10 healthy controls. Blood samples were collected -15, 0, 15, 30, 45, 60 and 90 min after injections. Sumatriptan induced a significant (p<0.01) decrease of ACTH, cortisol and prolactin concentrations both in patients with migraine and in controls. The neuroendocrine response was not significantly different in the two groups. Our results suggest that 5-HT1D receptor sensitivity is not altered in migraine.

Adrenocorticotropic Hormone↗

PubMed2000

Effects of subcutaneous sumatriptan on plasma growth hormone concentrations in migraine patients.

The purpose of this study was to assess the sensitivity of 5-HT1D receptors in migraine using sumatriptan as a pharmacological probe. The drug stimulates the release of growth hormone (GH) and this effect may be used to explore the function of cerebral serotonergic systems in vivo. We administered sumatriptan and placebo to 15 migraineurs and to 10 controls. Blood samples were collected -15, 0, 15, 30, 45, 60 and 90 min after injection. Placebo had no effect on hormone concentrations. Sumatriptan induced a significant (P<0.01) increase in GH concentrations both in migraine patients and healthy controls. The GH increase was not significantly different in the two groups. Our results suggest that cerebral serotonergic functions mediated by 5-HT1D receptors are not altered in migraine. Sumatriptan overuse could lead to adverse effects mediated by its neuroendocrine activity.

Adult↗