Prostaglandin f2[alpha] induces cardiac myocyte hypertrophy in vitro and cardiac growth in vivo. Lai, Jadine, Hongkui Jin, Renhui Yang, Jane Winer, Wei Li, Randy Yen, Kathleen L. King, Francis Zeigler, Annie Ko, Jennifer Cheng, Stuart Bunting, and Nicholas F. Paoni. Departments of Cardiovascular Research, BioAnalytical Technology, and the Cell Biology Group, Genentech, Inc., 460 Point San Bruno Blvd., South San Francisco, CA 94080
APStracts 3:0310H, 1996.
Several prostaglandins (A2, B2, D2, E2, F2[alpha], I2 and carbaprostacyclin) and the thromboxane analogue U46619 were analyzed for the ability to induce hypertrophy of rat neonatal cardiac ventricular myocytes. Myocyte hypertrophy was induced specifically by prostaglandin F2[alpha]. Myocytes exposed to this prostanoid in culture increased in size and protein content. The contractile fibrils within the cells became organized into parallel arrays, and the cells tended to cluster and beat spontaneously. F2[alpha] also induced the expression of c-fos, ANF, and [alpha]-skeletal actin in these cells. The effects of F2[alpha] were compared to several known cardiac myocyte hypertrophy factors (phenylephrine, endothelin-1, leukemia inhibitory factor (LIF), cardiotrophin-1 (CT-1), and angiotensin II). F2[alpha] was found to be intermediate in potency among the factors, but induced a level of ANF production that was approximately 10 fold higher than any of the other effectors. Responsiveness to F2[alpha] was not limited to neonatal cardiocytes. Ventricular myocytes isolated from adult rats also responded specifically to F2[alpha] with a morphological change similar to that observed with phenylephrine, and by producing ANF. In rats, chronic administration of fluprostenol, a potent agonist analogue of prostaglandin F2[alpha], resulted in a dose dependent increase in heart weight and ventricular weight to body weight ratios. The amount of F2[alpha] extractable from the hearts of rats with cardiac hypertrophy induced by myocardial infarction was also found to be greater than that of sham operated controls. These results indicate that F2[alpha] may play an important role in inducing cardiac hypertrophy.

Received 20 October 1995; accepted in final form 29 April 1996.
APS Manuscript Number H978-5.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 25 July 1996