Chlorpheniramine

At day 5 of pregnancy, pregnant rats received a single intraperitoneal injection of either a buffered citrate solution (vehicle; pH 7.4) for control rats or streptozotocin (STZ; Sigma–Aldrich, St. Louis, MO, USA; body weight: 50 mg/kg) for experimental rats (diabetic rats). From 24 h after vehicle or STZ injection until sacrifice the glucose level was measured daily using a drop of blood taken from the tail vein and a glucometer (ACCU-Chek Performa, Roche Diagnostics, Basel, Switzerland). Rats with glucose levels above 200 mg/dl were included in the diabetic group, while animals with <200 mg/dl levels were discarded.
To explore the possible role of H₁R in the increased neuron differentiation in embryos from diabetic rats, we performed a series of experiments, where injectable water (vehicle; Laboratorios PiSA S. A. de C. V., GDL. Jal. MEX) or 5 mg/kg of the H₁R antagonist chlorpheniramine (Sigma–Aldrich; Naranjo and de Naranjo, 1968 (link)) was intraperitoneally administrated to control and diabetic pregnant rats, at E12, and evaluated at E14.

Recombinant Human IFNγ (BD Biosciences, Australia), IL-1β, and TNFα (R&D Systems, Minneapolis, MN) were reconstituted in sterile PBS containing 0.1% bovine serum albumin (BSA). Histamine, chlorpheniramine, and ranitidine (Sigma-Aldrich, Sydney, Australia) were reconstituted in water for irrigation (Baxter, Sydney, Australia). Human lung tryptase (≥5,000 mU/mg/mL of vehicle consisting of 1 M NaCl, 50 mM sodium acetate, 0.01% sodium azide, and 50 μM heparin) was obtained from Calbiochem (La Jolla, CA, USA). BSA and leupeptin were purchased from Sigma-Aldrich. All agents were stored in aliquots at −20°C, except for IFNγ which was stored at −80°C.

RPMI 1640 and DMEM mediums, antibiotics, phosphate-buffered saline (PBS), phorbol 12-myristate 13-acetate (PMA), bovine serum albumin (BSA), ascorbic acid, β-glycerophosphate, dexamethasone, cetirizine, chlorpheniramine, azelastine and diphenhydramine were obtained from Sigma Chemical Company (St. Louis, MO, USA). Mepyramine maleate and trans-triprolidine were from Tocris Cookson Inc. (Ballwin, MO, USA). Fetal bovine serum (FBS) was purchased from Natocor (Córdoba, Argentina). All other chemicals were of analytical grade and obtained from standard sources.