title: Successful implantation of an abdominal aortic blood pressure transducer and radio-telemetry transmitter in guinea pigs - Anaesthesia, analgesic management and surgical methods, and their influence on hemodynamic parameters and body temperature.
abstract: BACKGROUND
  Guinea pigs (GPs) are a valuable cardiovascular pharmacology model. Implantation of a radio-telemetry system into GPs is, however, challenging and has been associated with a high failure rate in the past. We provide information on a novel procedure for implanting telemetry devices into GPs and we have measured the hemodynamics (arterial blood pressure, BP and heart rate, HR) and core body temperature (BT) in the 24h after surgery.
  
  
  METHODS
  Male Hartley GPs (Crl:HA, 350-400g, 6.5weeks, n=16) were implanted with a radio transmitter abdominally and were then monitored continuously (HR, BP and BT) for 24h after surgery.
  
  
  RESULTS
  13 of 16 GPs (81%) survived the surgery. Surgery duration was 94min (min) (range: 76-112min) and anaesthesia duration was 131min (range: 107-158min). GPs lost body weight until 2days after surgery and then regained weight. Mean arterial BP increased from 33.7mmHg directly after surgery to 59.1mmHg after 24h. HR increased from 206bpm directly after surgery to 286bpm at 8h and fell to 251bpm at 24h after implantation. BT was 36°C directly after surgery, fell to 35.4°C until regaining of the righting reflex and then stabilized at 38.5°C after 24h.
  
  
  CONCLUSIONS
  A high survival rate in telemetered GPs is possible. We achieved this through a procedure with minimal stress through habituation and planning, continuous warming during anaesthesia, an optimal anaesthetic and analgesic management, efficient surgical techniques and vitamin C supplementation.
authors.affiliation: Department of Nonclinical Drug Safety, Biological Laboratory Service, Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Str. 65, 88397 Biberach, Germany. Electronic address: sabrina.schmitz@boehringer-ingelheim.com.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Schmitz
authors.affiliation: Department of Nonclinical Drug Safety, Biological Laboratory Service, Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Str. 65, 88397 Biberach, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Henke
authors.affiliation: Department of Veterinary Clinical Sciences, Clinic for Small Animal-Surgery, Justus-Liebig-University, Frankfurter Str. 108, 35392 Giessen, Germany. Electronic address: Sabine.P.Tacke@vetmed.uni-giessen.de.
authors.forename: Sabine
authors.initials: S
authors.lastname: Tacke
authors.affiliation: Department of Drug Discovery Support, General Pharmacology, Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Str. 65, 88397 Biberach, Germany; DST/NWU Preclinical Drug Development Platform, Faculty of Health Sciences, North-West University, Potchefstroom, South Africa. Electronic address: brian.guth@boehringer-ingelheim.com.
authors.forename: Brian
authors.initials: B
authors.lastname: Guth
mesh_terms: D000698:Analgesia / Q000379:methods*; D000758:Anesthesia / Q000379:methods*; D000818:Animals; D000975:Antioxidants / Q000627:therapeutic use; D001012:Aorta, Abdominal / Q000502:physiology*; D001205:Ascorbic Acid / Q000627:therapeutic use; D001794:Blood Pressure / Q000502:physiology; D001831:Body Temperature / Q000502:physiology*; D001835:Body Weight; D006168:Guinea Pigs; D006339:Heart Rate / Q000502:physiology; D006439:Hemodynamics / Q000502:physiology*; D008297:Male; D015996:Survival Rate; D013686:Telemetry / Q000379:methods*; D014160:Transducers, Pressure
chemical_list: D000975:Antioxidants; D001205:Ascorbic Acid
keywords: Anaesthesia; Analgesia; Arterial blood pressure; Cavia porcellus; Core body temperature; Guinea pig; Heart rate; Implantation; Methods; Radio-telemetry