title: Effect of short-term organoid culture on the pharmaco-mechanical properties of rat extra- and intrapulmonary arteries.
abstract: 1 Organoid cultured explants from differentiated tissues have gained renewed interest in the undertaking of physiological and pharmacological studies. In the work herein, we examined the pharmaco-mechanical properties of an in vitro model consisting of organoid cultured rings derived from rat extra- and intrapulmonary arteries, over a period of 4 days in culture. 2 Mechanical changes were quantified using isometric tension measurements on both fresh and cultured pulmonary arterial tissues, with experiments performed in the presence or absence of 10% foetal calf serum. Conventional histochemical and immunofluorescent stainings were also performed to assess tissue structure integrity and apoptosis. 3 The explants developed spontaneous rhythmic contractions (SRC) in approximately half of the vessels. SRC amplitude and time course were modified by conditions and agents acting on membrane potential (high-potassium solutions--levcromakalim, a potassium channel opener), while nitrendipine, an L-type calcium channel blocker, suppressed SRC. 4 Cultured explants also developed a hyper-reactivity to high potassium challenges (10-40 mM). Whereas contraction to serotonin (5-HT) was enhanced in intrapulmonary arteries, contraction to endothelin-1 remained unchanged after 4 days of culture. Serum did not alter contractile properties during the culture period. 5 Endothelial-dependent relaxation was maintained in response to A23187 500 microM, but was abolished in response to 10 microM carbamylcholine. 6 Histological and immuno-histological analyses revealed the absence of hypertrophied vascular wall or apoptosis. 7 In conclusion, the contractile phenotype as well as tissue structure integrity of organoid explants remain essentially intact during short-term culture, making this model suitable for pharmaco-genomic studies.
authors.affiliation: Laboratoire de Physiologie Cellulaire Respiratoire, INSERM E356, Université Bordeaux 2, France. christelle.guibert@u-bordeaux2.fr
authors.forename: Christelle
authors.initials: C
authors.lastname: Guibert
authors.forename: Jean Pierre
authors.initials: JP
authors.lastname: Savineau
authors.forename: Huguette
authors.initials: H
authors.lastname: Crevel
authors.forename: Roger
authors.initials: R
authors.lastname: Marthan
authors.forename: Eric
authors.initials: E
authors.lastname: Rousseau
mesh_terms: D000818:Animals; D017209:Apoptosis; D007150:Immunohistochemistry; D007537:Isometric Contraction; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D009924:Organ Culture Techniques; D011651:Pulmonary Artery / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar