A Langendorff-like system to quantify cardiac pump function in adult zebrafish

Abstract

Zebrafish are increasingly used as a vertebrate model to study human cardiovascular disorders. Although heart structure and function are readily visualized in zebrafish embryos because of their optical transparency, the lack of effective tools for evaluating the hearts of older, nontransparent fish has been a major limiting factor. The recent development of high-frequency echocardiography has been an important advance for in vivo cardiac assessment, but it necessitates anesthesia and has limited ability to study acute interventions. We report the development of an alternative experimental ex vivo technique for quantifying heart size and function that resembles the Langendorff heart preparations that have been widely used in mammalian models. Dissected adult zebrafish hearts were perfused with a calcium-containing buffer, and a beat frequency was maintained with electrical stimulation. The impact of pacing frequency, flow rate and perfusate calcium concentration on ventricular performance (including end-diastolic and end-systolic volumes, ejection fraction, radial strain, and maximal velocities of shortening and relaxation) were evaluated and optimal conditions defined. We determined the effects of age on heart function in wild-type male and female zebrafish, and successfully detected hypercontractile and hypocontractile responses after adrenergic stimulation or doxorubicin treatment, respectively. Good correlations were found between indices of cardiac contractility obtained with high-frequency echocardiography and with the ex vivo technique in a subset of fish studied with both methods. The ex vivo beating heart preparation is a valuable addition to the cardiac function tool kit that will expand the use of adult zebrafish for cardiovascular research.

Retinoid X receptor alpha is a spatiotemporally predominant therapeutic target for anthracycline-induced cardiotoxicity

“…1, B, E, and F). Second, we assessed cardiac function using an ex vivo Langendorff-like system (25). While a reduced ventricular EF was noted in the wild-type fish at 10 weeks post-DOX injection (wpi) (48.2 ± 8.9% versus 57.3 ± 4.2%; P = 0.002), ventricular pump function was preserved in GBT0419/0419 ( fig.…”

“…We used our recently developed Langendorff-like perfused zebrafish heart technique (25). Briefly, hearts were isolated from tricaineanesthetized fish, cannulated by using 34-gauge ultrathin catheters through the atrioventricular canal visualized with a stereomicroscope Leica M165C (Leica, Germany), paced with an isolated stimulator MyoPacer (IonOptix; ~15 V, 10 ms, 2 Hz), and perfused using a peristaltic pump EP-1 Econo Pump (Bio-Rad).…”

Retinoid X receptor alpha is a spatiotemporally-specific therapeutic target for doxorubicin-induced cardiomyopathy in adult zebrafish

“…In contrast, RP2 reversion in cardiomyocytes and epicardial cells did not offset this survival-benefit ( Figure 2E, 2F). Second, we assessed cardiac function of adult zebrafish using a recently developed ex vivo Langendorff-like system (44). While reduced ventricular ejection fraction was noted in wild type fish at 10 weeks post DOX injection (wpi), GBT0419/0419 fish showed preserved pump function (Supplemental Figure 3B), indicating the salutary modifying effects on DIC is associated with a cardiac-specific protection.…”

“…We employed our recently developed Langendorff-like perfused zebrafish heart technique (44). Briefly, hearts were isolated from tricain-anesthetized fish, Ejection fraction = 1 -ESV/EDV.…”

Associação entre concentração de cálcio no dialisato e função ventricular sistólica durante a hemodiálise

“…Várias condições patológicas podem gerar alterações na homeostase do cálcio nos cardiomiócitos gerando um acumulo de cálcio intracelular, evento que está associado disfunção ventricular e a ocorrência MS148,149 . Baseado no estudo de Abbott e colaboradores, que utilizando modelo de isquemia e reperfusão em ratos, demonstraram piora de função ventricular associada a acúmulo de cálcio intracelular e dano mitrocondrial durante reperfusão miocárdica com solução com altas concentrações de cálcio150 , e em estudo com modelo de coração isolado, mais recente, que demonstrou piora de FE durante exposição a concentrações de cálcio extracelular mais elevadas151 , é plausível supor uma eventual influência da alta concentração de cálcio no dialisato, com elevação do cálcio sérico, na homeostase de cálcio intracelular nos cardiomiócitos, contribuindo para disfunção ventricular durante HD.Encontrarmos associação entre a piora do SLG no pico da HD com cálcio sérico pós-HD e não com o balanço de cálcio, fato que merece discussão. Nossos resultados sugerem que, pelo menos para o desempenho miocárdico, o cálcio sérico tem um impacto mais forte do que o balanço de cálcio.…”