title: Simultaneous subcutaneous implantation of two osmotic minipumps connected to a jugular vein catheter in the rat.
abstract: Subcutaneous osmotic pump implantation connected to a venous catheter is a well-established method for delivering compounds intravenously for an intermediate duration (approximately two weeks). When prolonged release is desired (approximately four weeks) reduced flow rate is needed with a similar pump volume. With a fixed intra-pump compound concentration, reduced flow rate results in unwanted reduced bioavailability of the compound. Prolonged intravenous delivery would therefore need a pump replacement, resulting in increased discomfort and confounding effects on experimental outcome. To overcome this, we describe a method to double the compound infusion rate for four weeks by implanting two low-flow rate osmotic pumps (2.5 µL/h for 28 days) connected to a jugular vein catheter in a single rat. Rats implanted with a single high-flow rate pump (5 µL/h for 14 days) served as controls. Double pump-implanted rats displayed similar post-operative weight gain and physical activity indicating similar levels of discomfort when compared with single pump-implanted rats. Double pump-implanted rats had an increased risk of pump-related complications (four delivery failures [double pump] versus one delivery failure [single pump]). Our data show that double pump implantation is a feasible alternative to changing pumps or the use of extracorporeal pump systems connected via a long wire to partly restrained animals.
authors.affiliation: Department of Pathology & Medical Biology, Pathology Section, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Johannes
authors.initials: J
authors.lastname: Wedel
authors.affiliation: Central Animal Facility, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Michel
authors.initials: M
authors.lastname: Weij
authors.affiliation: Central Animal Facility, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Annemieke Smit-van
authors.initials: AS
authors.lastname: Oosten
authors.affiliation: Department of Pathology & Medical Biology, Pathology Section, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands j.l.hillebrands@umcg.nl.
authors.forename: Jan-Luuk
authors.initials: JL
authors.lastname: Hillebrands
mesh_terms: D000818:Animals; D002405:Catheterization, Central Venous / Q000009:adverse effects / Q000295:instrumentation*; D016503:Drug Delivery Systems / Q000009:adverse effects / Q000295:instrumentation*; D005260:Female; D015918:Infusion Pumps, Implantable / Q000009:adverse effects / Q000592:standards*; D007601:Jugular Veins; D008297:Male; D051381:Rats; D017208:Rats, Wistar
keywords: drug delivery; intravenous administration; osmotic pump; rat; refinement