Which type of reins a rider uses, split reins or one rein, is a matter of personal preference. Split reins are commonly seen in the Western riding disciplines, although some Western riders might use one rein. Split reins are heavily preferred by most working cowboys and cowgirls.
Antimicrotubule agent, mitotic inhibitor Oncology An agent that inhibits cancer growth by stopping cell division Pharmacology A drug that inhibits or blocks mitosis in a particular phase of the cell cycleâeg, metaphase arrest caused by colchicine and vinca alkaloids. See Chemotherapy.
a molecule that prevents an enzyme from catalysing a reaction. Such inhibitors can compete with the normal substrate (see COMPETITIVE INHIBITION or can block the active site, preventing entry of the substrate (see NONCOMPETITIVE INHIBITION). Inhibition may be reversible or irreversible. Enzyme inhibitors often form part of a FEEDBACK MECHANISM to regulate a biochemical pathway.