Pancreas Subject

P-Adrenoceptors have been subdivided into P - and P2-adrenoceptors. A third subset called nontypical P-adrenoceptors or P -adrenoceptors have been described but are stiU the subject of debate. In terms of the interactions with various subsets of P-adrenoceptors, some antagonists are nonselective in that they antagonize the effects of activation of both P - and P2-adrenoceptors, whereas others are selective for either P - or P2-adrenoceptors. P - and P2-adrenoceptors coexist in almost all organs but generally, one type predominates. The focus herein is on the clinically relevant P -adrenoceptor-mediated effects on heart and on P2-adrenoceptor-mediated effects on smooth muscles of blood vessels and bronchioles, the insulin-secreting tissue of the pancreas, and skeletal muscle glycogenolysis for side effects profile (36). 

Various cyclic esters have been subjected to hpase-catalyzed ring-opening polymerization. Lipase catalyzed the ring-opening polymerization of 4- to 17-membered non-substituted lactones.In 1993, it was first demonstrated that medium-size lactones, 8-valerolactone (8-VL, six-membered) and e-caprolactone (e-CL, seven-membered), were polymerized by lipases derived from Candida cylindracea, Burkholderia cepacia (lipase BC), Pseudomonas fluorescens (lipase PF), and porcine pancreas (PPL). °... 

Human amylin, or islet amyloid polypeptide (hlAPP), is a 37-residue peptide hormone which forms both intracellular and extracellular (EC) amyloid deposits in the pancreas of most type II diabetic subjects. The core of the structure in the SDS micelle is an ot-helix that runs from about residues 5-28. Although the basic structural unit in the fibrils in... 

A 29-year-old man presented with acute pancreatitis after a period of heavy cannabis smoking. Other causes of the disease were ruled out. The pancreatitis resolved itself after the cannabis was stopped and this was confirmed by urinary cannabinoid metabolite monitoring in the community. There were no previous reports of acute pancreatitis associated with cannabis use in the general population. Drugs of all types are related to the etiology of pancreatitis in approximately 1.4-2% of cases k Pancreatic toxicity. The dried leaf, smoked by a 19-year-old woman, was active. The subject was hospitalized with pancrea-titis . 

Other microbial lipases have also been successfully used in anhydrous ionic liquids, e.g., from Alcaligenes sp. (AsL) [54, 58], CaLA, Rhizomucor miehei lipase (RmL), and Thermomyces lanuginosus lipase (TIL) [54]. The lipase from pig pancreas (porcine pancreas lipase, PPL), the only mammalian lipase that has been subjected to ionic liquids, catalyzed transesterificationin[BMIm][NTf2]butnotin[BMIm][PF6]... 

In the Montreal case-control study carried out by Siemiatycki (1991) (see monograph on dichloromethane in this volume), the investigators estimated the associations between 293 workplace substances and several types of cancer. Isocyanates were one of the substances, and it was stated that the most common form in this study was toluene diisocyanates. The main occupations to which isocyanate exposure was attributed in this study were motor vehicle refinishers, motor vehicle mechanics and foundry workers. Only 0.8% of the study subjects had ever been exposed to isocyanates. For most types of cancer examined (oesophagus, stomach, colon, rectum, pancreas, prostate, bladder, kidney, skin melanoma, lymphoma), there was no indication of an excess risk due to isocyanates. For lung cancer, in the population subgroup of French Canadians (the majority ethnic group in this region), based on 10 cases exposed at any level, the odds ratio was 2.2 (90% CI, 0.9-5.3). [The interpretation of the null results has to take into account the small numbers and presumably low exposure levels. Workers had multiple exposures.]... 

Neri et al89 reported the desymmetrization of A-Boc-serinol 98 by the selective monoacetylation using PPL (porcine pancreas lipase) and vinyl acetate as the acylating agent in organic solvent. The mono acetylated product (R)-99 was obtained after 2 hours with 99% ee and isolated in 69% chemical yield. Traces of the diacetylated product 100 were observed. The cyclization of (R)-99 in basic medium afforded the racemic oxazolidinone 101. The latter was subjected to enzymatic hydrolysis in phosphate buffer affording (R)-... 

This discussion of the metalloexopeptidases has focused on the general role of these enzymes in the conversion of dietary proteins into amino acids. In particular, the apparent synergistic relationship which the pancreatic carboxypeptidases have with the major endopeptidases, trypsin, chymotrypsin, and pepsin, in order to facilitate formation of essential amino acids has been stressed. The chemical characteristics, metalloenzyme nature, and mechanistic details of a representative of each class of exopeptidase have been presented. Leucine aminopeptidase from bovine lens was shown to be subject to an unusual type of metal ion activation which may be representative of a more general situation. Carboxypeptidase A of bovine pancreas was discussed in terms of its three-dimensional structure, the implications of x-ray crystallography to mecha ... 

Insulin, naturally secreted by the pancreas, enters the portal vein and passes straight to the liver, where half of it is taken up. The rest enters and is distributed in the systemic circulation so that its concentration (in fasting subjects) is only about 15% of that entering the liver. 

A deficiency or surfeit of certain hormones can influence the activity of the enzymes involved in drug biotransformation. Apart from the sex hormones, those of the adrenal, pancreas, pituitary, and thyroid also exert effects on the regulation of certain enzyme activities. Some hormonal disease states, such as diabetes and hyperthyroidism, could have important implications for drug biotransformation. Alterations in drug biotransformation can occur in pregnancy, and this subject area requires much more study. 

The interaction of tacrolimus with fluconazole has been retrospectively evaluated in 19 kidney and pancreas/kid-ney transplant recipients (90). Both intravenous and oral fluconazole altered the blood concentration of tacrolimus. Five subjects did not have a significant interaction and 15 did. No patient had nephrotoxicity or transplant rejection related to antifungal therapy. 

The effect of high-dose pancreatic enzymes on pancreatic function has been assessed in a double-blind study in 12 healthy volunteers, six of whom were given 18 capsules of Panzjhrat (20 000 units of lipase, 18 000 units of amylase, and 1000 units of protease per capsule) daily for 4 weeks (4). There were no morphological or functional changes in the pancreas in those treated. None of the subjects had severe adverse effects. Two had transient mild nausea, epigastric pain, and heartburn. There were no abnormalities in hver function tests. 

FIGURE 4.8 Plasma C-peptide levels after a glucagon injection. The increases in plasma C-peptide reflect changes in the rate of release of insulin from the pancreas. The C-peptide level more than doubled in the normal subject ( ), and increased more moderately in the diabetic (O). (Redrawn with permission from Marchesini et al, 1985.)... 

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