By hydrophobic gel permeation and high pressure liquid chromatography we isolated from pig intestinal mucosa a peptide which corresponds to proglucagon 78–107 as suggested by chromatography and determination of its N‐terminal sequence. Natural and synthetic proglucagon 78–107 dose dependently and potently increased insulin secretion from the isolated perfused pig pancreas. Proglucagon 78–107 also secreted by the small intestine may participate in the hormonal control of insulin secretion.

We developed specific antibodies and RIAs for glucagon-like peptides 1 and 2 (GLP-1 and GLP-2), two predicted products of the glucagon gene, and studied the occurrence, nature, and secretion of immunoreactive GLP-1 and GLP-2 in pig pancreas and small intestine. Immunoreactive GLP-1 and GLP-2 were identified in glucagon-producing cells of the pancreatic islets, and in glicentin-producing cells of the small intestine. Immunoreactive GLP-1 and 2 in intestinal extracts corresponded in molecular size to peptides synthesized according to the predicted structure. By reverse phase HPLC, intestinal and synthetic GLP-1 behaved similarly, whereas synthetic and intestinal GLP-2 differed. Pancreatic extracts contained a large peptide with both GLP-1 and GLP-2 immunoreactivity. Secretion was studied using isolated perfused pig pancreas during arginine stimulation, and isolated perfused pig ileum during either luminal glucose stimulation or vascular administration of the neuropeptide, gastrin-releasing peptide (GRP). Immunoreactive GLP-1 and GLP-2 were secreted in parallel with pancreatic glucagon and intestinal glicentin. The molecular forms of secreted immunoreactive GLP-1 and 2 corresponded to those identified in the tissue extracts.

We studied the effect of truncated glucagon-like peptide-1 [naturally occurring GLP-1; proglucagon-(78-107) amide], a potent insulinotropic peptide from the pig ileum, on endocrine and exocrine secretion of potential gastrointestinal target organs using isolated perfused preparations of the porcine pancreas, antrum, and nonantral part of the stomach. Truncated GLP-1 significantly increased somatostatin secretion from the pancreas at 10(-10) mol/liter and more than doubled the secretion at 10(-9) mol/liter, but had no effect on either somatostatin or gastrin secretion from the antrum or on somatostatin secretion from the nonantral stomach in concentrations up to 10(-8) mol/liter. Insulin secretion from the pancreas (with 7 mmol/liter glucose in the perfusate) increased 2-fold with truncated GLP-1 at 10(-10) mol/liter and almost 5-fold at 10(-9) mol/liter. Pancreatic glucagon secretion was inhibited by 50% at 10(-10) mol/liter and by 70-80% at 10(-9) mol/liter. Full-length GLP-1 [proglucagon-(72-107)] and GLP-2 [proglucagon-(126-159)] had no effect on hormone secretion from any of the perfused organs. It is concluded that truncated GLP-1 may participate in an entero-insular control of pancreatic endocrine secretion.

A B S R A C T The effect of efferent, parasympathetic stimulation upon pancreatic polypeptide (PP) secretion was studied in three ways: (a) Plasma PP concentrations increased in response to insulin-induced hypoglycemia in both normal subjects, from 11 pM (9.5-12.5) to 136 pM (118-147), n = 8 (median and interquartile range) and in duodenal ulcer patients, from 33 pM (21-52) to 213 pM (157-233), n = 7. The PP response to hypoglycemia was diminished by atropine in normal subjects (P <

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Abstract. Particle size distribution (size-range 3-900 nm) and PM10 was measured simultaneously at an urban background station in Copenhagen, a near-city background and a rural location during a period in September-November 2002. The study investigates the contribution from urban versus regional sources of particle number and mass concentration.The total particle number (ToN) and NO x are well correlated at the urban and near-city level and show a distinct diurnal variation, indicating the common traffic source. The average ToN at the three stations differs by a factor of 3. The observed concentrations are 2500 # cm −3 , 4500 # cm −3 and 7700 # cm −3 at rural, near-city and urban level, respectively. PM10 and total particle volume (ToV) are well correlated between the three different stations and show similar concentration levels, in average within 30% relative difference, indicating a common source from long-range transport that dominates the concentrations at all locations.Measures to reduce the local urban emissions of NO x and ToN are likely to affect both the street level and urban background concentrations, while for PM10 and ToV only measurable effects at the street level are probable. Taking into account the supposed stronger health effects of ultrafine particles reduction measures should address particle number emissions.The traffic source contributes strongest in the 10-200 nm particle size range. The maximum of the size distribution shifts from about 20-30 nm at kerbside to 50-60 nm at rural level. Particle formation events were observed in the 3-20 nm size range at rural location in the afternoon hours, mainly under conditions with low concentrations of preexisting aerosol particles.The maximum in the size distribution of the "traffic contribution" seems to be shifted to about 28 nm in the urban Correspondence to: M. Ketzel (mke@dmu.dk) location compared to 22 nm at kerbside. Assuming NO x as an inert tracer on urban scale allows to estimate that ToN at urban level is reduced by 15-30% compared to kerbside. Particle removal processes, e.g. deposition and coagulation, which are most efficient for smallest particle sizes (<20 nm) and condensational growth are likely mechanisms for the loss of particle number and the shift in particle size.

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