Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0847097 (acidity)
 15,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Highly purified growth hormone (GH) has been isolated from Atlantic salmon (Salmo salar) pituitaries by extraction with acid acetone, acidic precipitation, and reversed-phase high-performance liquid chromatography (HPLC). The yield was 2.5 mg/g wet tissue. The Atlantic salmon GH (sGH) emerged as a single symmetrical peak after HPLC on a reverse phase C18 column. SDS-gel electrophoresis revealed only one band with an estimated molecular weight of 23,000. Atlantic sGH showed a uniform molecular weight, but two-dimensional (2D) gel electrophoresis of the purified sGH revealed charge heterogeneity with pI's ranging from 6.5 to 8.2. Treatment of the purified sGH with alkaline phosphatase concentrated these different forms into a single more alkaline position (pI 8.2) indicating removal of acidic groups. These results were documented using both silver- and immunostaining of the 2D SDS gels. The purified sGH was phosphorylated in vitro by a calmodulin-dependent protein kinase. Phosphorylation of sGH may be a post-translational modification resulting in several molecular forms with variable acidity. Analysis of the amino acid composition of Atlantic sGH revealed homology with GHs isolated from other teleost species and the amino-terminal sequence showed only three different amino acids within the first 25 residues compared to GH isolated from chum salmon (Oncorhynchus keta) and coho salmon (Oncorhynchus kisutch) pituitaries. Atlantic sGH had a methionine as the amino-terminal residue. Antibodies against chum sGH cross-reacted with Atlantic sGH. Antibodies against either Atlantic or chinook (Oncorhynchus tschawytscha) salmon prolactin or human GH did not cross-react with Atlantic sGH. Atlantic sGH was shown to have a slight growth-promoting activity in the rat tibia assay.
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PMID:Purification and characterization of Atlantic salmon growth hormone and evidence for charge heterogeneity. 228 75

1. Both starch gel and disk electrophoresis demonstrated stepwise degradation of acidic preparations of human and bovine growth hormones and of ovine and bovine lactogenic hormones in solution at pH 9.0-10.0. This developed in 1-3 weeks in refrigerated solutions and in 5-16 hr on incubation at 37 degrees C. Increasing acidity accompanied degradation.2. Oxytocic activity, initially absent, developed in these same solutions of hormones during stepwise degradation and appeared to be associated with a single phase of degradation.3. Storage in solution at pH 9.5 generated oxytocic activity in an initially basic preparation of ovine growth hormone. The uterine action was attributable to a small amount of acidic material with electrophoretic properties very similar to those of the oxytocic fractions formed during stepwise degradation of the acidic preparations of growth and lactogenic hormones.4. Prolonged storage of all these hormones at pH 9.0-10.0 resulted in the formation of acidic substances of low molecular weight which ran close to the buffer front and were dialysable (14 hr) through membranes which permitted the passage of nonapeptides in 6-8 hr.5. alpha-Chymotrypsin very rapidly generated uterine stimulant action in freshly prepared solutions of human growth and bovine lactogenic hormones at pH 9.5.6. All the hormone samples used proved capable of hydrolysing purified ox haemoglobin, urea-denatured, at pH 9.5.
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PMID:The formation of peptides with uterine activity from ovine, human and bovine growth hormones and from bovine and ovine lactogenic hormones. 594 11

A method has been described for the isolation of three differently charged isohormones of rat prolactin from a discard fraction obtained after extraction of gonadotropins, thyrotropin and growth hormone from homogenized frozen pituitaries. The procedure involved extraction at pH 9.8, ammonium sulphate fractionation, molecular sieve chromatography on Sephadex G-100, and column electrophoresis in agarose suspension. The purification was monitored by radioimmunoassays and the recovered components were all found to possess a specific immunoactivity exceeding that of the standard preparation (RP-1) supplied by the NIAMDD, Bethesda, U.S.A. Increased acidity among these isohormones was found to be paralleled by significantly decreased immunopotency. Each component showed biological activity in radioreceptor assay. A high degree of purity of the isolated components was shown by analytical electrophoresis in polyacrylamide gel. Sodium dodecyl sulphate electrophoresis in the same medium showed no size heterogeneity and yielded a value of approximately 25 000 for the molecular weight of the isohormones. In addition a large form of prolactin, suggested to represent a dimer, was isolated by a further extraction step (pH 10.5) followed by molecular sieve chromatography on Sephadex G-100 and electrophoresis in agarose suspension. The large form was associated with both biopotency and immunopotency. The electrophoresis resolved the prolactin activity into three or four immunoactive components. This pleomorphism of the large prolactin was confirmed by analytical polyacrylamide gel electrophoresis. Amino acid analyses revealed a close similarity between the three monomers and the major dimeric form of the hormone.
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PMID:Isolation of rat pituitary prolactin isohormones differing in charge, size, and specific immunological activity. 712 24

Episodic acidification resulting in increased acidity and inorganic aluminum (Al(i)) is known to interfere with the parr-smolt transformation of Atlantic salmon (Salmo salar), and has been implicated as a possible cause of population decline. To determine the extent and mechanism(s) by which short-term acid/Al exposure compromises smolt development, Atlantic salmon smolts were exposed to either control (pH 6.7-6.9) or acid/Al (pH 5.4-6.3, 28-64 microgl(-1) Al(i)) conditions for 2 and 5 days, and impacts on freshwater (FW) ion regulation, seawater (SW) tolerance, plasma hormone levels and stress response were examined. Gill Al concentrations were elevated in all smolts exposed to acid/Al relative to controls confirming exposure to increased Al(i). There was no effect of acid/Al on plasma ion concentrations in FW however, smolts exposed to acid/Al followed by a 24h SW challenge exhibited greater plasma Cl(-) levels than controls, indicating reduced SW tolerance. Loss of SW tolerance was accompanied by reductions in gill Na(+),K(+)-ATPase (NKA) activity and Na(+),K(+),2Cl(-) (NKCC) cotransporter protein abundance. Acid/Al exposure resulted in decreased plasma insulin-like growth factor (IGF-I) and 3,3',5'-triiodo-l-thyronine (T(3)) levels, whereas no effect of treatment was seen on plasma cortisol, growth hormone (GH), or thyroxine (T(4)) levels. Acid/Al exposure resulted in increased hematocrit and plasma glucose levels in FW, but both returned to control levels after 24h in SW. The results indicate that smolt development and SW tolerance are compromised by short-term exposure to acid/Al in the absence of detectable impacts on FW ion regulation. Loss of SW tolerance during short-term acid/Al exposure likely results from reductions in gill NKA and NKCC, possibly mediated by decreases in plasma IGF-I and T(3).
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PMID:Effects of short-term acid and aluminum exposure on the parr-smolt transformation in Atlantic salmon (Salmo salar): disruption of seawater tolerance and endocrine status. 1860 7

Nonalcoholic fatty liver disease (NAFLD), frequently already present in young subjects, has been linked to reduced growth hormone levels and signaling. Similar hormonal changes occur during metabolic acidosis (MA), which may thus contribute to an increased NAFLD risk. Because subclinical MA can be diet induced, we aimed to examine whether a higher diet-dependent acid load during adolescence is prospectively associated with several currently used NAFLD surrogates in young adulthood. Dietary acidity during adolescence (boys:10-15 y, girls: 9-14 y) was calculated as potential renal acid load (PRAL) from at least three 3-d weighed dietary records according to a published algorithm considering dietary protein and minerals in 145 healthy participants. Routine measurements derived from blood analysis and anthropometric data in participants' young adulthood (18-25 y) were used to determine the NAFLD surrogates alanine-aminotransferase (ALT), hepatic steatosis index (HSI), and fatty liver index (FLI). Sex-stratified linear regression models, adjusted for dietary fiber, saturated fat, protein, and adolescent BMI SD scores, were run with PRAL as the independent variable. Dietary PRAL during puberty was positively associated with ALT (P = 0.02), HSI (P = 0.002), and FLI (P = 0.005) in adult females but not males. Females with an adolescent dietary acid load in the highest tertile had 3.5, 4.4, and 4.5 higher values of ALT, HSI, and FLI as adults, respectively, compared to females with the lowest PRAL. The present findings suggest that higher dietary acidity in adolescence may be prospectively associated with hepatic lipid accumulation in females. Whether this relationship is due to the higher proton load or rather represents an unhealthy dietary pattern requires further investigation.
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PMID:Long-term dietary potential renal acid load during adolescence is prospectively associated with indices of nonalcoholic fatty liver disease in young women. 2222 73

The present study was to investigate the effects of diltiazem, a ghrelin receptor agonist, on food intake and gastrointestinal functions in rats. Rats were intragastrically administered with diltiazem solution (daily 16 mg/kg, 30 mg/kg or 80 mg/kg, 30 d), and the rats with saline as control. To detect the effects of diltiazem on food intake and body weight, the average daily food intake and body weight were recorded, and the serum metabolic hormones of plasma growth hormone (GH) and neuropeptide Y (NPY) were tested by radioimmunoassay. By means of the spectrophotometer and the modified Mett's method, the effects of diltiazem on rat's gastrointestinal function and pepsin activity were tested, respectively. In addition, the gastric juice's acidity of rats was detected by titration and the secretion amount was calculated. The results showed that the food intake and body weight were maximally promoted by diltiazem at the dose of 30 mg/kg daily (30 d). The average daily food intake and body weight were significantly increased, and the serum concentrations of GH and NPY were also remarkably increased in diltiazem-treated groups compared with those in control group. The results also showed that the gastric emptying rate, gastric acid secretion and the activity of pepsin were significantly increased in diltiazem-treated group compared with those in control group. These results suggest that diltiazem induces enhancement of eating, in the same time, it can also stimulate the gastrointestinal function and regulate growth of rat.
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PMID:[Diltiazem enhances food intake and gastrointestinal function in rats]. 2251 69