Discovery and development of direct thrombin inhibitors the binding site for the globular amino-terminal domain and exosite 1 is the binding site for the acidic carboxy-terminal domain of hirudin. Native hirudin, a 65-amino-acid polypeptide, is produced in the parapharyngeal glands of medicinal leeches. Hirudins today are produced by recombinant biotechnology using yeast. These recombinant hirudins lack a sulfate group at Tyr-63 and are therefore called desulfatohirudins. They have a 10-fold lower binding affinity to thrombin compared to native hirudin, but remain a highly specific inhibitor of thrombin and have an inhibition constant for thrombin in the picomolar range. Renal clearance and degradation account for the most part
Brunner's glands Brunner's glands Brunner's glands (or duodenal glands) are compound tubular submucosal glands found in that portion of the duodenum which is above the hepatopancreatic sphincter (a.k.a. sphincter of Oddi). The main function of these glands is to produce a mucus-rich alkaline secretion i.e. Mucous (containing bicarbonate) in order to: They also secrete urogastrone, which inhibits parietal and chief cells of the stomach from secreting acid and their digestive enzymes. This is another form of protection for the duodenum. They are the distinguishing feature of the duodenum, and are named for the Swiss physician who first described them, Johann Conrad Brunner.