title: Voluntary intake of paracetamol-enriched drinking water and its influence on the success of embryo transfer in mice.
abstract: Embryo transfer (ET) in mice is a key technique in biomedical research, and is carried out mostly via surgery by transferring founder embryos into pseudo-pregnant recipient females. To cover post-operative analgesic requirements in surrogate mothers, oral self-administration of painkillers has several advantages, but its effectiveness has also been criticized as voluntary ingestion of the drug can be uncertain. Additionally, concerns about potential negative side effects of analgesics on embryo viability and development have been raised. In this regard, we investigated the impact of orally administered analgesia by comparing the outcome of ET with and without paracetamol in the drinking water (3.5mg/ml) of surrogate mothers. Water intake increased significantly when paracetamol, as a sweet-tasting formulation (children's syrup), was added to the drinking water. Measurements of paracetamol concentrations in blood serum confirmed reasonable drug uptake. Success rate of ETs and the body weight of newborn offspring were not different whether paracetamol was administered for two days after surgery or not. In conclusion, paracetamol in drinking water was consumed voluntarily in substantial doses, without detectable side-effects, by freshly operated surrogate mothers, and can therefore be recommended as a feasible method for providing analgesic treatment for surgical ET in mice.
authors.affiliation: Division of Surgical Research, Centre for Clinical Research, University Hospital Zurich, Sternwartstrasse 6, 8091 Zurich, Switzerland. Electronic address: Thea.Fleischmann@usz.ch.
authors.forename: Thea
authors.initials: T
authors.lastname: Fleischmann
authors.affiliation: Division of Surgical Research, Centre for Clinical Research, University Hospital Zurich, Sternwartstrasse 6, 8091 Zurich, Switzerland. Electronic address: Margarete.Arras@usz.ch.
authors.forename: Margarete
authors.initials: M
authors.lastname: Arras
authors.affiliation: Division of Surgical Research, Centre for Clinical Research, University Hospital Zurich, Sternwartstrasse 6, 8091 Zurich, Switzerland. Electronic address: Mareike.Sauer@usz.ch.
authors.forename: Mareike
authors.initials: M
authors.lastname: Sauer
authors.affiliation: Institute of Clinical Chemistry, University of Zurich and University Hospital Zurich, Rämistr. 100, 8091 Zurich, Switzerland. Electronic address: Lanja.Saleh@usz.ch.
authors.forename: Lanja
authors.initials: L
authors.lastname: Saleh
authors.affiliation: Institute of Laboratory Animal Science, Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria. Electronic address: Thomas.Ruelicke@vetmeduni.ac.at.
authors.forename: Thomas
authors.initials: T
authors.lastname: Rülicke
authors.affiliation: Division of Surgical Research, Centre for Clinical Research, University Hospital Zurich, Sternwartstrasse 6, 8091 Zurich, Switzerland. Electronic address: Paulin.Jirkof@usz.ch.
authors.forename: Paulin
authors.initials: P
authors.lastname: Jirkof
mesh_terms: D000082:Acetaminophen / Q000494:pharmacology*; D000284:Administration, Oral; D018712:Analgesics, Non-Narcotic / Q000494:pharmacology*; D000818:Animals; D060766:Drinking Water / Q000032:analysis*; D004624:Embryo Transfer; D005260:Female; D051379:Mice; D010149:Postoperative Pain / Q000188:drug therapy*; D011897:Random Allocation
chemical_list: D018712:Analgesics, Non-Narcotic; D060766:Drinking Water; D000082:Acetaminophen
keywords: Acetaminophen; Embryo transfer; Mice; Paracetamol; Water intake