1. The NPY Y1 receptor antagonist BIBP 3226 blocks NPY induced feeding via a non-specific mechanism
A P Goldstone, C J Small, D M Smith, S Bloom, D G Morgan, I Gunn, S Abusnana, M Ghatei, D O'Shea, M Turton, K Meeran, M Rossi, M Heath Regul Pept . 1998 Sep 25;75-76:377-82. doi: 10.1016/s0167-0115(98)00091-3.
We have previously shown that intracerebroventricular BIBP 3226 inhibits NPY induced feeding in rats. However, this was associated with abnormal behaviour, likely to be due to interaction with Y1 receptors involved in mechanisms other than the control of food intake. In order to minimise such interactions we investigated the effects of paraventricular nucleus (PVN) injections of BIBP 3226 and its inactive enantiomer BIBP 3435. Intra-PVN injection of NPY (0.1-2.5 nmol/animal) increased food intake, with an EC50 of approximately 0.15 nmol/animal. Injections of BIBP 3226 and BIBP 3435 (0.25-25 nmol) reduced NPY-induced food intake in a dose responsive manner, with BIBP 3226 reducing food intake by 95%, and BIBP 3435 by 65% at the highest dose tested. The reversibility of the effect of BIBP 3226 was investigated by measuring the feeding response to NPY (0.5 nmol) in animals 1 week after BIBP 3226 injection. The response to NPY was less in animals which had received high doses of BIBP 3226. Animals previously injected with saline vehicle alone showed a normal NPY feeding response. These results suggest that BIBP 3226 may be inhibiting NPY-induced food intake in a non-specific manner, not secondary to inhibition of the Y1 receptor. This does not, however rule out a role for the Y1 receptor in the control of food intake by NPY.
2. Determination of neuropeptide Y Y1 receptor antagonist BIBP 3226 and evaluation of receptor expression based on liquid chromatography coupled with tandem mass spectrometry
Marcela A Segundo, Inês S Alencastre, Meriem Lamghari, Eduarda M P Silva, Luisa Barreiros Anal Bioanal Chem . 2020 Sep;412(24):6625-6632. doi: 10.1007/s00216-020-02825-z.
Neuropeptide Y (NPY) is a peptide widely distributed throughout the body that is involved in various physiological processes, including the regulation of feeding behavior and energy homeostasis. 5-Carbamimidamido-2-(2,2-diphenylacetamido)-N-[(4-hydroxyphenyl)methyl]pentanamide (BIBP 3226) is a selective NPY Y1 receptor antagonist with recognized application in bone regeneration studies, requiring quantification at picogram levels. Hence, BIBP 3226 determination is proposed here by a validated HPLC-MS/MS method, based on a reversed-phase Kinetex® core-shell C8 column (2.6 μm, 150 × 2.1 mm) at 30 °C, elution in isocratic mode using a mixture of acetonitrile and water (30:70, v/v), containing 0.1% (v/v) formic acid, at 0.25 mL min-1, detection in positive ionization mode, and data acquisition in selected reaction monitoring mode. Calibration curves were linear for concentrations ranging from 0.25 to 30 ng mL-1with LOD and LOQ values as low as 0.1 and 0.3 pg in cell extracts and 16 and 48 pg in supernatant culture media, respectively. BIBP 3226 was successfully determined in cell extracts and supernatants obtained from internalization assays. Using similar exposure conditions, the amount of BIBP 3226 found in breast cancer cells (MCF7) was 72 to 657 times higher than that found in bone marrow cells (Wt C57BL/6 mice), providing an indirect indicator of NPY Y1 receptor expression.
3. The effect of a neuropeptide Y antagonist, BIBP 3226, on short-term arterial pressure control in conscious unrestrained rats with congestive heart failure
W Zhang, J M Lundberg, P Thorén Life Sci . 1999;65(17):1839-44. doi: 10.1016/s0024-3205(99)00435-x.
The effects of a neuropeptide Y (NPY) Y1-receptor antagonist (BIBP 3226) on mean arterial pressure (MAP) and heart rate were investigated in conscious unrestrained rats with chronic congestive heart failure. The rats were randomly assigned to 2 groups, and received either BIBP 3226 or its inactive enantiomer (BIBP 3435) as an intravenous infusion (6 mg/kg/h for 1.5 h, respectively). Before, during and after the infusion, rats were stressed with a jet of air and received a bolus injection of NPY (2 nmol/kg iv.). There was no difference between the 2 groups in resting MAP and heart rate before, during or after infusion (BIBP 3226 vs. BIBP 3435). The effects of exogenous NPY on MAP were significantly attenuated in BIBP 3226 group during and 1 h after the infusion (p<0.05). The tissue NPY levels in heart, adrenal gland and kidney in heart failure rats were not different from those in sham-operated rats. The results suggest that Y1-receptor mechanisms are of minor importance in the short-term control of basal MAP and heart rate in conscious unrestrained rats with congestive heart failure.
