The recent experimental measurement of the gamma to 3 pi coupling constant is compared with the prediction of an extended PCAC hypothesis. Consistency is then sought between the omega rho pi coupling constant, as obtained from an analogue of the GT relation for vector mesons, and what is predicted by the low-energy theorems. A remarkable relation for the dimensionless coupling constant g(rho pi pi) emerges, mod g(rho pi pi) mod =2 pi. The authors also find that the coupling constant g(omega rho 0 pi 0), as obtained from the GT relation for vector mesons, does not support an omega pi pi pi contact term. © 1987 IOP Publishing Ltd.