Effects of the calcitonin gene-related peptide (CGRP) receptor antagonist BIBN4096BS on alpha-CGRP-induced regional haemodynamic changes in anaesthetised rats.
ABSTRACT Several studies suggest that a calcitonin gene-related peptide (CGRP) receptor antagonist may have antimigraine properties, most probably via the inhibition of CGRP-induced cranial vasodilatation. We recently showed that the novel selective CGRP receptor antagonist, BIBN4096BS (1-piperidinecarboxamide, -N-[2-[[5-amino-1-[[4-(4-pyridinyl)-1-piperazinyl] carbonyl] pentyl]amino]-1-[(3,5-dibromo-4-hydroxyphenyl) methyl]-2-oxoethyl]-4-(1,4-dihydro-2-oxo-3(2H)-quinazolinyl)-, [[R-(R,(R*,S*)]), attenuated the CGRP-induced porcine carotid vasodilatation in a model predictive of antimigraine activity. In order to evaluate the potential safety of BIBN4096BS in migraine therapy, this study was designed to investigate the effects of intravenous BIBN4096BS on alpha-CGRP-induced systemic and regional haemodynamic changes in anaesthetised rats, using radioactive microspheres. In vehicle-pretreated animals, consecutive intravenous infusions of alpha-CGRP (0.25, 0.5 and 1 microg kg(-1) min.(-1)) dose-dependently decreased mean arterial blood pressure with an accompanying increase in heart rate and systemic vascular conductance whereas cardiac output remained unchanged. Alpha-CGRP also increased the vascular conductance to the heart, brain, gastrointestinal tract, adrenals, skeletal muscles and skin, whilst that to the kidneys, spleen, mesentery/pancreas and liver remained unaltered. The above systemic and regional haemodynamic responses to alpha-CGRP were clearly attenuated in BIBN4096BS (3 mg kg(-1) intravenously)-pretreated animals. These results indicate that exogenously administered alpha-CGRP dilates regional vascular beds via CGRP receptors on the basis of the antagonism produced by BIBN4096BS. Moreover, the fact that BIBN4096BS did not alter baseline haemodynamics suggests that endogenously produced CGRP does not play an important role in regulating the systemic and regional haemodynamics under resting conditions.
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ABSTRACT: The triggers of the acute local inflammatory response to peritoneal dialysis (PD) fluid exposure remain unknown. In the present study, we investigated the effects of neurogenic inflammation and mast cell degranulation on water and solute transport in experimental PD. Single 2-hour dwells in rats with PD catheters were studied. Histamine and the neuropeptides substance P and calcitonin gene-related peptide (CGRP) were measured in PD fluid samples by ELISA. Radiolabeled albumin ((125)I and (131)I respectively) was used as an intraperitoneal (IP) and intravascular tracer. Glucose and urea concentrations were measured in plasma and PD fluid. The effects of varying the volume and osmolarity of a lactate-buffered PD fluid were compared and related to the effects of pharmacologic intervention. Application of 20 mL 3.9% glucose PD fluid induced an IP histamine release during the first 30 minutes, blockable by the mast cell stabilizer doxantrazole and the substance P neurokinin-1 receptor (NK1R)-blocker spantide. Histamine release was also inhibited at a reduced PD volume (14 mL), but was not affected by normalizing the PD fluid osmolarity. Blockade of NK1R also reduced plasma albumin leakage to the peritoneal cavity. Inhibition of CGRP receptors by CGRP8-37 improved osmotic (transcapillary) and net ultrafiltration and reduced the dialysate urea concentration. Neuropeptide release was not clearly related to activation of the TrpV1 receptor, the classic trigger of neurogenic inflammation. Neuropeptide release exaggerated albumin loss and reduced ultrafiltration in this rat PD model. Intervention aimed at the neuropeptide action substantially improved PD efficiency.Peritoneal dialysis international : journal of the International Society for Peritoneal Dialysis. 09/2011; 32(2):168-76.
- Headache The Journal of Head and Face Pain 06/2013; 53(6):1004-6. · 2.94 Impact Factor
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ABSTRACT: INTRODUCTION: Migraine afflicts approximately 11% of the population worldwide producing substantial disability, resulting in loss of productivity both at home and at the workplace. Calcitonin gene-related peptide (CGRP) is closely involved in the cascade of molecular events leading to migraine painful crisis. AREAS COVERED: Acute treatment of migraine is actually based on the use of triptans, class drug which presents a clear limitation due to its cardiovascular side effects. Gepants, a CGRP antagonist class, might offer a new non-vasoconstrictive approach in the acute treatment of migraine. Four chemically unrelated CGRP receptor (CGRP-R) antagonists (olcegepant, telcagepant, MK-3207 and BI 44370 TA) have displayed efficacy in the treatment of migraine. EXPERT OPINION: When compared with triptans, gepants class showed a similar efficacy, moreover corresponding to the best published results for oral triptans. CGRP antagonists are in different phases of their development, and the treatment of migraine could be based on the use of gepants, as class of acute medications. However, CGRP-R antagonists clinical trials seem to be discouraging for their forthcoming use in clinical practice. New CGRP-R antagonists, such as BMS-927711 and BI 44370 TA, are in the pipeline and their developments will outline the future of this drug class.Expert Opinion on Investigational Drugs 04/2012; 21(6):807-18. · 4.74 Impact Factor