Muscle hypertrophy is dependent on the ammount of ATP present in the muscle fibers. The higher the ATP levels, the better the environment for muscle growth.
Higher repetition Sets develop the numbers of mitochondria in muscle fibers which in turn can now produce higher levels of ATP - in effect increasing strength levels and promoting higher levels of hypertrophy.
When performing low repetition sets however, mitochondria levels dont increase, and might even decrease (correct me if Im wrong). This means sub-optimal levels of ATP produced by the muscle fiber. In this instance, where does the ATP come from? Since Growth is dependent upon levels of ATP present in the muscle fiber (along many other factors), it would be reasonable to say very low repetition exercise for PROLONGED periods of time would eventually stall muscle HYPERTROPHY (not necessarily strength).
Unless, there is a major flaw in my reasoning, or if muscle fibers with little mitochondria can get ATP from other sources, then the ideal recipe for continued muscle growth would by necessity have to incroporate periods of sarcoplasmic hypertrophy where mytochondria levels go up but Actin/Myosin hypertrophy is minimal, followed by low repetition work where Actin/Myosin hypertophy occurs - now in an environment where there is an abundance of ATP. Thus, alternating moderate-high repetition with low repetition training would be a necessity, not just a cool trick for maximal hypertrophy gains.
Just rambling, and all the pieces might be out of place. Please correct me if Im wrong - and Im sure Goldberg will have some interesting contributions.