Does the "credit channel" of monetary policy disappear when interest rates are very low?

We seek to determine whether the following mechanism can appear: Central bank interest rates are cut, interest rates on bank loans initially fall, and this reduces banks' intermediation margins and earnings; Banks' reaction to the decline in their profitability is to increase the risk premia integrated in loan interest rates: when central bank interest rates continue to be cut, loan interest rates fall less and less; This stabilises bank profitability, but removes the credit channel from monetary policy. Past developments in the United States and the euro zone show that in periods of very low interest rates, the risk premia incorporated in bank loan interest rates actually do rise, thereby removing or at least weakening the credit channel .