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Effect of motilin antiserum infusion on porcine IDMCS
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MECHANISMS OF MOTILIN RELEASE BY METOCLOPRAMIDE Garvan Institute T.Borody, D. Byrnes and L. Henderson. St. Vincent's Hospital, Darlinghurst, 2010, Australia.
of Medical
Research,
Metoclopramide (MET) has been found to be a potent stimulus for motilin release'. The aim of this study was to determine - a. the mechanisms of motilin release by MET; b whether the increase in motility following MET is due to motilin release. MET (lOOug/ml) failed to stimulate motilin release from perifused human duodenal mucosa specimen whereas motilin release occurred after taurocholate perifusion (15mmol/L) and acidification of the perifusate. Release of motilin following intravenous MET in 6 volunteers was inhibited by neutralization of gastric contents by an antacid; ii. tnhibited by pretreatment with atropine (15ug/kg) ; iii. did not occur in patients with achlorhydria (pernicious anaemia). Furthermore, motilin release after MET was variable and duodenal motor activity was observed (perfused pressure recordings) in some subjects to occur before the increase in plasma motilin. It is concluded that i. MET releases motilin; ii. the stimulus for release of motilin after MET is the emptying of acid into the duodenum and iii. the effect of MET on duodenal motility is independent of motilin release. ' D. BYRNES, L. HENDERSON, C. MEREDITH Aust.N.2. J. Med., 1980, 10:109.
and T. BORODY.
EFFECT OF MOTILIN ANTISERUM INFUSION ON PORCINE IDMCS T.Borody*, D.Byrnes*, J. Slowiaczek+ and D. Titchen+. Garvan Institute Medical Research*, 2010 and University of Sydney+, 2006, Australia.
of
Evidence that motilin is the hormone responsible for initiation of interdigestive myoelectric complexes (IDMCS) depends on the enhanced motilin levels observed during IDMCSl and the induction of similar activity by motilin infusion 2 . The aim of the present study was to observe the effect on IDMCS of in vivo motilin neutralization. Electrical activity of the antrum, duodenum and two sites on the jejunum was recorded with the aid of multi-stranded fluorocarbon-covered stainless steel wires. These were placed in two pigs when they were about 8kg body weight. Recordings of activity were first undertaken 10 days later. Antiserum specific for porcine motilin raised by immunizing rabbits with motilin conjugated to egg albumin was used. This had an affinity of 5.5x10 i 'L/M and a capacity of 1.89umol/L. In a dilution of l/2000 the antiserum bound >90% of porcine motilin (lOOpmol/L) within 5 min at 37Oc. Control infusions were carried out using normal rabbit serum. IDMCS were identified by their four phases, the aboral progression and quiesence following an activity front. Infusion of motilin antiserum which achieved an in vivo concentration of >1/2000 during its administration over 4 hours failed to affect the onset of the complexes in the duodenum in either pig and although in one pig these continued to be followed normally by jejunal complexes, this association was changed in the other pig in which prolonged duodenal-jejunal transmission intervals were observed. It is concluded from this immunoneutralization study that motilin is not essential for the initiation of IDMCS :" ITCH, the pig. 2. --' et al DIGEST.DIS., 23:929, 1978. ' WINGATE, D. --* et al SCAND.J.GAST., ll:(Supp1.39),
111, 1976.
MECHANISMS OF MOTILIN RELEASE BY METOCLOPRAMIDE Garvan Institute T.Borody, D. Byrnes and L. Henderson. St. Vincent's Hospital, Darlinghurst, 2010, Australia.
of Medical
Research,
Metoclopramide (MET) has been found to be a potent stimulus for motilin release'. The aim of this study was to determine - a. the mechanisms of motilin release by MET; b whether the increase in motility following MET is due to motilin release. MET (lOOug/ml) failed to stimulate motilin release from perifused human duodenal mucosa specimen whereas motilin release occurred after taurocholate perifusion (15mmol/L) and acidification of the perifusate. Release of motilin following intravenous MET in 6 volunteers was inhibited by neutralization of gastric contents by an antacid; ii. tnhibited by pretreatment with atropine (15ug/kg) ; iii. did not occur in patients with achlorhydria (pernicious anaemia). Furthermore, motilin release after MET was variable and duodenal motor activity was observed (perfused pressure recordings) in some subjects to occur before the increase in plasma motilin. It is concluded that i. MET releases motilin; ii. the stimulus for release of motilin after MET is the emptying of acid into the duodenum and iii. the effect of MET on duodenal motility is independent of motilin release. ' D. BYRNES, L. HENDERSON, C. MEREDITH Aust.N.2. J. Med., 1980, 10:109.
and T. BORODY.
EFFECT OF MOTILIN ANTISERUM INFUSION ON PORCINE IDMCS T.Borody*, D.Byrnes*, J. Slowiaczek+ and D. Titchen+. Garvan Institute Medical Research*, 2010 and University of Sydney+, 2006, Australia.
of
Evidence that motilin is the hormone responsible for initiation of interdigestive myoelectric complexes (IDMCS) depends on the enhanced motilin levels observed during IDMCSl and the induction of similar activity by motilin infusion 2 . The aim of the present study was to observe the effect on IDMCS of in vivo motilin neutralization. Electrical activity of the antrum, duodenum and two sites on the jejunum was recorded with the aid of multi-stranded fluorocarbon-covered stainless steel wires. These were placed in two pigs when they were about 8kg body weight. Recordings of activity were first undertaken 10 days later. Antiserum specific for porcine motilin raised by immunizing rabbits with motilin conjugated to egg albumin was used. This had an affinity of 5.5x10 i 'L/M and a capacity of 1.89umol/L. In a dilution of l/2000 the antiserum bound >90% of porcine motilin (lOOpmol/L) within 5 min at 37Oc. Control infusions were carried out using normal rabbit serum. IDMCS were identified by their four phases, the aboral progression and quiesence following an activity front. Infusion of motilin antiserum which achieved an in vivo concentration of >1/2000 during its administration over 4 hours failed to affect the onset of the complexes in the duodenum in either pig and although in one pig these continued to be followed normally by jejunal complexes, this association was changed in the other pig in which prolonged duodenal-jejunal transmission intervals were observed. It is concluded from this immunoneutralization study that motilin is not essential for the initiation of IDMCS :" ITCH, the pig. 2. --' et al DIGEST.DIS., 23:929, 1978. ' WINGATE, D. --* et al SCAND.J.GAST., ll:(Supp1.39),
111, 1976.