Absorption of Functionally Active Arginine-Vasotocin in the Frog Small Intestine

Absorption of arginine-vasopressin and arginine-vasotocin in small intestine of the frog Rana temporaria

“…If to take into account that in this experiment the administration into the gut of 0.1 µmol AVP amounted to 42 µg/100 mg of mass of the gut, it can accept that into the Ringer solution of volume of 30 ml there was absorbed approximately 0.24 µg AVP, or 0.6% of the introduced amount of hormone. Such result (about 1%) was obtained earlier [19] when 0.22-0.26 nmol AVT (0.25 µg/100 mg of the gut mass) were introduced into the gut. With decrease of the gut incubation time with AVP together with urinary bladders to 10 min at the similar hormone dose (0.12 µmol, or 42 µg/100 g gut mass) the increase of water flow across the urinary bladder wall was less significant and slower, but significant as compared with control after 30 and 45 min to amount to 0.31 ± 0.08 µl/min · cm 2 and 0.49 ± 0.12 µl/min · cm 2 , respectively ( p < 0.05).…”

“…The mass of the isolated gut amounted to 240 ± 8 mg (n = 35). Composition of the solution and the detailed description of the procedure were exposed earlier [19].…”

“…The delivery of the hormone (AVP or AVT) across the intestinal wall into the solution from the side of serosa was judged from the hydroosmotic reaction of 5-8 urinary bladders into the vessel to which the gut was fixed. The water flow across the urinary bladder wall by osmotic gradient (µl/min · cm 2 ) was determined by hydroosmotic method [21] in the process of periodic weighing of the urinary bladders on the electron scale connected with computer and by subsequent calculations [19].…”

“…Absorption of these hormones without disturbance of structure of the molecules is indicated by their antidiuretic effect on kidney. A possibility of passage of nonapeptides across the intestinal epithelial barrier was also established in experiments in vitro [18][19][20]. Interest in the problem of absorption of polypeptides is obvious not only due to their use as medicinal drugs.…”

“…Interest in the problem of absorption of polypeptides is obvious not only due to their use as medicinal drugs. Absorption of functionally active AVT [19] as well as of intact green fluorescent protein [9] has been shown to occur in small intestine not INTRODUCTION By the present time, the abundant data have been accumulated about that some amount of proteins and polypeptides can be absorbed in the gastrointestinal tract totally, without preliminary hydrolysis. This is indicated by clinical analysis of diseases caused by entrance to organism of foreign proteins with food [1,2].…”