Decrease In Amylase Activity Research Articles

Subclinical exocrine pancreatic derangement in human diabetic patients evaluated from pure pancreatic juice

To elucidate the mechanism responsible for histological derangement of pancreas in diabetic patients, pure pancreatic juice (PPJ) aspirated directly from pancreatic duct was analyzed before and after strict glycemic control on poorly controlled diabetic patients without clinical exocrine pancreatic dysfunction. PPJ obtained from 18 diabetics showed a significantly decreased amylase activity compared with ten healthy subjects (109 ± 4 versus 168 ± 9 U/mg protein, p < 0.005) in spite of negligible changes in lipase activity, protein concentration, bicarbonate concentration, and its volume. PPJ showed higher concentrations of prostanoids in diabetic patients than in healthy subjects (TXB 2, 259 ± 48 versus 118 ± 30 pg/mL, p < 0.05; 6-keto-PGF1α, 52.6 ± 11.5 versus 38.5 ± 7.5 pg/mL, p > 0.05). Ratio of 6-keto-PGF1α/TXB 2 of PPJ in diabetic patients was significantly lower than in healthy subjects (0.195 ±0.016 versus 0.422 ± 0.041, p < 0.005). After strict glycemic control for 1–3 months on nine of 18 diabetic patients, amylase activity of PPJ was significantly higher than that before the control (112 ± 4 versus 128 ± 7 U/mg protein, p < 0.01), but still significantly lower than that of healthy subjects ( p < 0.005). Lipase activity showed no significant difference between before and after the control. TXB 2 and 6-keto-PGF1α concentrations were decreased. Ratio of 6-keto-PFG1α/TXB 2 after the control (0.320 ± 0.038) significantly ( p < 0.005) increased from 0.168 ± 0.019 and reached a comparable level to that of healthy subjects. These data indicated that pure pancreatic juice in poorly controlled diabetics showed a significantly lower amylase activity and a decreased ratio of 6-keto-PGF1α/TXB 2, implying local derangement in exocrine pancreas by hyperglycemia. Strict glycemic control was proven to normalize the imbalance in prostanoids but not completely improve a decreased amylase activity.

Effect of modifying histidine residues on the action of Bacillus amyloliquefaciens and barley-malt α-amylases

Modification of porcine pancreatic alpha-amylase (PPA) and Taka-amylase A(TAA) with diethyl pyrocarbonate (DEP) causes activation of the release of p-nitrophenol from p-nitrophenol alpha-maltoside (G2PNP), and a decrease in amylase activity (hydrolysis of alpha-1,4 glucosidic bonds in starch). Among the possible sites of modification, attention focuses on three histidine residues present around the active site of alpha-amylases of many different origins. In PPA these are His 101, His 201, and His 299, with His 101 and His 299 being very close to the site of catalysis and thus perhaps directly or indirectly involved in the catalysis. On the other hand, His 201 is located on the aglycon side of the catalytic site, and we have suggested that it is involved in the increase of PNP release after chemical modification. Investigations of site-directed mutagenesis of the histidine residues of human pancreatic alpha-amylase support this identification. Although the degree of sequence similarity among alpha-amylases of different origins is low, there are several conserved short regions. Most belong to the structural components of the active site in PPA and TAA. Furthermore, there is a close similarity in the three-dimensional structures of PPA and TAA. The conserved residues around the active site in all alpha-amylases suggest some universal structural similarities in these active sites. Therefore, we examined the effects of the chemical modification of histidine residues in Bacillus amyloliquefaciens alpha-amylase(BLA) with DEP and made a comparison with modification of barley alpha-amylase isoenzyme II(BAII), using identical substrate systems. These two alpha-amylases have more substrate binding subsites than PPA and TAA, and have similar action patterns with malto-oligosaccharides.

Changes in amylase activity of Leptomysis lingvura in relation to experimental feeding conditons

1. 1. All the specimens except the reference samples were starved over a 24 hr period before feeding, and some of them were maintained in strict starvation for several days. Amylase activity was measured in single adults from capture to 1 month in laboratory conditions. 2. 2. Seasonal variations of amylase activity were obtained with higher values in the autumn than in the summer. 3. 3. Starvation induced an increase in activity during the first 24 hr, followed by a stabilization period or a slight decrease in activity. 4. 4. Different time scales were taken into account regarding the effects of food on amylase activity: from 15 min to 3.30hr (very short-term), from 1 to 8 days (short- and medium-term) and up to 29 days (long-term). 5. 5. At very short-term, food intake induced a very quick decrease in amylase activity during the first hour which was already noticeable after 15 min. 6. 6. This decrease was twice as significant after a 3 day, than after a 3 hr period of starvation. 7. 7. The following increase shows the existence of a very short-term regulation. 8. 8. At short- and medium-term, animals were fed on three different diets (Tetramin, yeast and Ulvae); at long-term they were only fed Tetramin. Feeding yielded three different results: the effect of food intake, the effect of quality of the food, and finally acclimation. 9. 9. On D 1 a significant increase in amylase activity was observed, followed by a time-lag of 24 hr (D 2) in the course of which no differences appeared regardless of the different diets. From D 4 to D 8 the quality of the food induced different changes in amylase activity with an increase rate significantly higher with Tetramin than with yeast or Ulvae. 10. 10. On a longer time scale (D 14, D 21, D 29), amylase activity decreased and stabilized at a level similar to that observed in the lag period (D 1-D 2): the effect of quality of the food disappeared and animals were acclimated to the experimental feeding conditions.

A 13-week subacute oral toxicity study of 6-amidino-2-naphthyl 4-[(4,5-dihydro-1H-imidazol-2-yl) amino] benzoate dimethanesulfonate (FUT-187) in rats

The toxicity of FUT-187, a synthetic protease inhibitor, was investigated in Sprague-Dawley rats. FUT-187 was given orally to the rats at doses of 2, 10, 50, 250 and 1250 mg/kg/day for 13 weeks, then the drug was withdrawn for 5 weeks for recovery. The results are summarized as follows: In the 1250 mg/kg/day group, 9 out of 20 males died with decreased body weight and exhaustion. Histopathological examination revealed renal papillary necrosis, ulcer in the urinary bladder, hemostatic lesions in the lungs and liver, ulcer or erosion in the stomach, duodenum and jejunum. The surviving animals in this group showed swelling of the limbs due to synovitis, transient salivation immediately after administration, suppression of growth with decreased food consumption. Urinalysis revealed a low pH, increased ketones and bilirubin excretion, dark yellowish change in color, the appearance of "leaflet-shaped" crystals and increased red blood cells and epithelial cells in the urinary sediment, increased water intake, decreased specific gravity and decreased sodium, potassium and chloride in the urine. Hematologically, there was an increase in the white blood cell count. A biochemical analysis of the blood revealed decreased amylase activity, glucose and total protein levels and increased GOT activity and inorganic phosphorus levels. Pathological changes were observed in the pancreas, kidney, digestive tract, urinary bladder and liver. The pancreas showed macroscopical enlargement and increased organ weight. Histopathologically, there were several alterations in the acinar cells, such as vacuolization due to increased fat droplets, nuclear irregularity, prominent nucleoli, irregular arrangement and vesiculation of rough endoplasmic reticulum (rER), dilatation of developed Golgi apparatus and increased free ribosomes. In the kidney, increased weight and pigmentation in the proximal tubular epithelium were noted. Electron microscopically, these pigments were recognized as secondary lysosomes containing filamentous material and electron dense granules within a lucent matrix. In the digestive tract, ulcer or erosion in the stomach and duodenum, and villous proliferation in the small intestine were observed. Furthermore, hyperplasia and vacuolization were noted in the mucosal epithelium of the urinary bladder. In addition, loss of perilobular fat droplets in the liver and increased adrenal weight without histological change were observed. After a 5-week recovery period, these changes disappeared almost completely. In the 250 mg/kg/day group, slight suppression of growth the appearance of "leaflet-shaped" crystals in the urinary , sediment, increased water intake and decreased sodium in the urine were observed. The pancreas showed enlargement, increased weight, acinar cell hypertrophy with increased zymogen granules, fine vacuolization, slight derangement and vesicular of rER, and dilatation of Golgi apparatus.(ABSTRACT TRUNCATED AT 400 WORDS)

The anticoordinate changes of pancreatic lipase and colipase activity to amylase activity induced by adrenalectomy in normal and diabetic rats

The effect of adrenalectomy (Adx) on pancreatic lipase and colipase activities in normal, streptozotocin-induced diabetic, and obese Zucker rats was studied. It was found that Adx induced a rapid decrease in amylase activity, a rapid increase in lipase activity, and a slow increase in colipase activity in normal rats. Twenty days after Adx, the levels of amylase activity were 70% lower than control, whereas the activities of lipase and colipase were 55 and 25% higher than control, respectively. The replacement of hydrocortisone normalized the changes in the three enzyme activities. Injection of insulin partially corrected the amylase activity, but had no significant effect on the activities of lipase and colipase. In streptozotocin-induced diabetic rats and obese Zucker rats, amylase activity was decreased, and lipase and colipase activities increased, compared to normal rats. These changes of enzyme activity were further enhanced by Adx. It is concluded that Adx results in an anticoordinate change in pancreatic lipase, colipase, and amylase activities, suggesting that glucocorticoid also influences the synthesis of the pancreatic lipolytic enzymes.

Enzyme depletion in insect feeding experiments: Fact or artifact?

1. 1. Musca domestica larvae were fed polyacrylamide gels to induce starvation and subsequently were fed starch gels. 2. 2. Amylase activity decreased in midgut cells during starvation and increased on refeeding, whereas in midgut contents it decreased along the whole experiment. 3. 3. The majority of the luminal amylase is soluble, although in refed larvae there is a significant amount which is pelleted on centrifuging. 4. 4. The calculated values for amylase activity remaining in midgut content of starved and refed larvae, taking into account literature data for amylase excretion in M. domestica larvae, agreed with the experimental values. 5. 5. The results suggest that amylase excretion in the absence of amylase secretion is the main event causing the decrease of amylase activity on refeeding. 6. 6. Another important event is the co-sedimentation of amylase with starch during homogenate clearing by centrifugation. 7. 7. These explanations probably also hold for other luminal hydrolases, making unnecessary the misleading concept of “enzyme depletion by the substrate”.

Influence of H+Ca++, and Mn++on the development of amylase in the endosperm of several sorghum cultivars1

Abstract Sorghum [Sorghum bicolor (L.) Moench] seeds (Funks G522DR) were planted in ‘white quartz flintshot’ and watered with 0.01 M NaAc buffer at pH 4.0, 4.5, 5.0, 5.5, or 6.0 ± Ca++ (0, 10, 100 ppmw) or Mn++ (0, 1.4, 140.0 ppmw) and grown for seven days in a growth chamber. Endosperm amylase contents, quantitatively and qualitatively, were dependent upon the environmental conditions during germination. H+ concentration at pH 4.0 strongly induced a decrease in amylase activity which was relieved as the pH was raised to pH 6.0. Ca++ greatly increased endosperm amylase contents. Mn++ (1.4 ppmw) tended to increase endosperm amylase contents while Mn++ (140.0 ppmw) strongly decreased endosperm amylase content. In the cultivar SC283, endosperm amylase contents were nearly double those found in Funks G522DR while SC574 had, at most, one half the endosperm amylase content of Funks G522DR endosperm. Endosperm amylase contents of SC283 were pH tolerant while those of Funks G522DR and SC574 were highly pH sensiti...

Selective inhibition of histidine-modified pancreatic α-amylase by proteinaceous inhibitor from Phaseolus vulgaris

Chemical modification of two histidine residues of porcine pancreatic α-amylase (EC 3.2.1.1) by diethyl pyrocarbonate in the presence of a high concentration of maltotriose caused a decrease of amylase activity and an increase of maltosidase activity (hydrolysis of p-nitrophenyl-α-maltoside). By binding a proteinaceous inhibitor from Phaseolus vulgaris (white kidney bean) with the modified enzyme, the amylase activity was further decreased but the maltosidase activity was retained to about 100% that of the native enzyme. Both amylase and maltosidase activities of the native enzyme were almost completely inhibited by the proteinaceous inhibitor. The increase of maltosidase activity by histidine modification was due to an increase of k cat, whereas the K m value was not changed; but binding of the proteinous inhibitor affected mainly the K m value of the modified enzyme.

Joint effects of dimilin and Ambush on enzyme activities of Tribolium castaneum larvae

Sublethal concentrations of 10 and 20 ppm (0.25 and 0.5 μ M) Ambush decreased amylase activity and increased acid phosphatase (AcP) and lactate dehydrogenase (LDH) activites in sixthinstar Tribolium castaneum. Dimilin at 250 and 500 ppm (8 and 16 μ M) raised activities of amylase, AcP, LDH, and alanine aminotransferase (ALAT) and depleted trehalase activity. The remaining enzymes, cholinesterase (ChE), alkaline phosphatase (AkP), asparate aminotransferase (ASAT), and isocitrate dehydrogenase (ICDH), were not affected by either insecticide. Mixtures of Dimilin and Ambush at 250 ± 10 and 500 ± 20 ppm resulted in a disturbance of almost all the enzymes tested in this study, suggesting a possible synergistic effect with reference to trehalase, ASAT, and AkP activities and an antagonistic effect with reference to amylase, AcP, LDH, ICDH, ChE, and ALAT activities. Feeding on untreated flour did not restore any of the affected enzyme activities to normal levels.

Impairment of pancreatic acinar function by reserpine in vivo and in vitro

Chronic reserpine treatment of animals, an experimental model for cystic fibrosis (CF), results in generalized exocrinopathy, impaired pancreatic secretion, and decreased pancreatic content of amylase. The mechanisms of altered acinar function and decreased amylase content in both CF and the reserpine-treated rat are unknown. To examine this alteration, the rate of [3H]phenylalanine (phe) incorporation into cellular protein was determined in pancreatic acinar cells after reserpine treatment of rats in vivo (7 d) and of cells in vitro (1 to 24 h). Acinar cells isolated from control, chronic reserpine-treated, and pair-fed rats were incubated in vitro with 0, 30, 50, or 100 microM reserpine. Reserpine treatment in vitro for 24 h of acinar cells from control rats significantly decreased amylase activity (20 to 70%), an effect similar to that of reserpine treatment in vivo. In vivo, reserpine treatment decreased [3H]phe incorporation (disintegrations per minute per milligram protein) 56% in freshly isolated cells, but did not alter intracellular specific activity (disintegrations per minute per nanomole phe, SA) of [3H]phe. Reserpine treatment (30 and 50 microM) in vitro for 1 h also decreased [3H]phe incorporation by freshly isolated cells from control (53 to 85%) and pair-fed (40 to 68%) rats. Reserpine treatment for 24 h in vitro significantly decreased [3H]phe incorporation by cells from control (82 and 98%), pair-fed (80 and 95%), and chronic reserpine-treated (90 and 97%) rats as compared with cells from respective in vivo treatments cultured with no reserpine. In vitro reserpine treatment also decreased the intracellular SA of [3H]phe in freshly isolated cells from control (14 and 36%) and pair-fed (35 and 39%) rats and in cultured cells from control (11 and 86%), pair-fed (60 and 88%), and chronic reserpine-treated (49 and 76%) rats. However, these alterations of SA by reserpine did not account for the decreased incorporation of [3H]phe into acinar protein, which remained significantly lower (70 to 88%) when expressed as total phe incorporation. These results suggest that reserpine acts directly on acinar cells to alter function and that the ability of the pancreas to synthesize digestive enzymes may be impaired in this model of cystic fibrosis.

Decrease in amylase (EC3.4.21.4) synthesis in lactating rats

The amylase (EC 3.4.21.4) and trypsin (EC 3.2.1.1) activities in the pancreas in rats during pregnancy, lactation and after the weaning period, and the secretory responses to a secretagogue (caerulein) in the exocrine pancreas of lactating rats were measured. Trypsin activity increased as lactation progressed and reached twice that of unmated rats in the second half of the lactation period. The amylase activity fell before parturition and failed to recover even after the start of lactation and was significantly decreased throughout the lactation period. The total amount of pancreatic juice produced in the lactating rats was significantly greater than that of unmated rats; the amylase output was significantly less than that of unmated rats. When the pups were removed, amylase activity in the pancreas returned to the value in unmated rats. Furthermore, the amylase activity in lactating rats receiving a daily injection of insulin significantly exceeded that of normal lactating rats. These results indicate that the decrease in amylase activity in lactating rats is due to the reduction of amylase synthesis and there is a possibility that insulin is required for normal or elevated rates of amylase synthesis in lactating rats.

Long-Term Ethanol Ingestion Does Not Increase the Toxicity of Peritoneal Exudate Generated during Acute Haemorrhagic Pancreatitis in Rats

Thirty male Wistar rats were randomly divided into two groups. One group received 15% (vol/vol) ethanol as their only drinking solution for 12 weeks; the rest of the animals served as controls, receiving tap water only. Acute haemorrhagic pancreatitis (AHP) was induced with a retrograde infusion of 5% sodium taurocholate into the pancreatic ducts, and the generated peritoneal exudate was collected 5 h after induction. When compared with the water-receiving control rats, chronic ethanol ingestion decreased amylase activity (p less than 0.001) and trypsin-inhibiting capacity (TIC) (p less than 0.001), whereas protein concentration was increased (p less than 0.001) in the peritoneal exudate collected from the ethanol-receiving group. The toxicity of the peritoneal exudate was assessed by intraperitoneal injections of the exudate from rats into mice (n = 90). Saline or injections of the peritoneal exudate from the rats that received water did not kill any mice, and exudate from the rats that had been drinking the mixture of ethanol and water killed one mouse. In conclusion, chronic ethanol ingestion does not increase the toxicity of the peritoneal exudate secreted during AHP in this experimental model. In AHP, however, ethanol consumption increases protein concentration and decreases TIC in peritoneal exudate. Hence, the balance of the protease-antiprotease system may be of importance to the outcome of AHP.

Decreased Amylase Activity of the Pancreas in NOD Mice

Decreased Amylase Activity of the Pancreas in NOD Mice

Inhibitory action of thyrotropin-releasing hormone on serum amylase activity and its mechanism.

The effect of im administration of 500 micrograms TRH on serum amylase activity was studied in 34 normal women, 6 women with primary hypothyroidism, 1 woman with anorexia nervosa, 6 women with hyperthyroidism due to Graves' disease, and 5 women with renal failure on chronic hemodialysis. Serum amylase activity decreased significantly in 31 of 34 normal subjects 60 to 120 min after administration of TRH. However, amylase isoenzymes were not significantly affected after administration of TRH, suggesting that TRH equally affects pancreatic and salivary amylase activity. TRH was also effective in patients on chronic hemodialysis, indicating that TRH does not reduce serum amylase activity by increasing urinary excretion of amylase. Since TRH reduced serum amylase activity in hyperthyroid patients in whom TRH failed to stimulate TSH secretion, TRH does not reduce serum amylase activity through increased secretion of TSH. The action of TRH was not mediated by serum thyroid hormone levels since TRH was similarly effective in patients with hypothyroidism or hyperthyroidism. TRH did not inhibit or interfere with amylase determination when added in vitro to heparinized blood. Perfusion of the dog pancreas with TRH reduced amylase activity in pancreatic juice and pancreatic venous blood. The magnitude of the decrease was related to the dose of TRH used. Since decrease in amylase activity of the pancreatic juice preceded that in pancreatic venous blood, TRH probably directly acts on the pancreas to reduce amylase secretion. As a result, serum amylase activity decreased after administration of TRH.

Eimeria Spp.: Influence of coccidia on digestion (amylolytic activity) in broiler chickens

Loss in pancreatic weight and an overall decrease in amylolytic activity in the pancreas were seen in broiler chickens infected with Eimeria acervulina, E. maxima, and E. necatrix. Only E. acervulina and E. maxima reduced amylolytic activity in the surface mucosa of the regions they infected. Surface-bound amylolytic activity decreased as the severity of infection (as measured by lesion score) with E. acervulina increased. This decrease in activity was not related to the decreased feed consumption in infected birds. Little decrease in amylase activity was found in the lumenal contents with the exception of E. acervulina in the jejunum. When the effect of pH on enzyme activity was studied in vitro, a marked reduction in amylolytic activity was observed as the pH went below 5.0.

Amylase activity, glycoprotein and electrolyte concentration in rat's submaxillary salivary gland during heat acclimation

1. 1. Amylase activity, glycoproteins, Na and K concentrations were measured in submaxillary salivary gland of the rat during heat acclimation (34°C). 2. 2. Acclimation resulted in a decrease in glycoprotein concentration and amylase activity, whereas Na and K concentrations and the Na/K ratio increased. 3. 3. It is suggested that heat acclimation results in an increase in glandular activity leading to increased water secretion and depletion of the glycoprotein store. The decrease in amylase activity is probably due to liver atrophy which occurs during prolonged heat exposure.

Age-Dependent Changes in the α-Isoamylase Pattern of Human and Rat Parotid Glands

Polyacrylamide gel electrophoresis shows four isoamylases in extracts prepared from rat parotid glands. With increasing age of the animals, a general decrease of amylase activity runs parallel with ch

The role of insulin in the regulation of -amylase synthesis in the rat pancreas.

Abstract. Changes in pancreatic exocrine enzyme activities were studied in different forms of experimental diabetes in rats. The effects of adrenalectomy on these changes were measured. The early actions of insulin on pancreatic enzyme activities and on incorporation of (4,5‐3H)‐leucine into amylase were also determined. The main results are: Alloxan‐diabetes leads to a decrease in amylase activity, a decreased rate of amylase synthesis and an increase in the activities of trypsinogen and chymotrypsinogen as described by Palla et al. [9]. Only the decrease in amylase activity correlates with the increase in blood glucose concentration. Adrenalectomy does not reverse the changes in the activities of exocrine pancreatic enzymes induced by diabetes. Diazoxide‐diabetes is accompanied by an increase in all pancreatic enzyme activities, most probably due to the inhibition of enzyme secretion. After treatment with streptozotozin a significant decrease in pancreatic amylase activity appears after 36 h. Amylase activity continues to fall during the following days, in contrast the increase in the activities of proteolytic enzymes is not significant until the 4th day. Insulin treatment of severely diabetic, non‐ketotic rats leads, as early as 90 min. after injection, to a significant increase in pancreatic amylase activity with no change in the other exocrine enzyme activities. A decrease in all enzyme activities, seen 6 h after insulin, is due to enhanced enzyme secretion. As soon as 2 h after injection insulin leads to a significant increase in the incorporation of (4,5‐3H)‐leucine into pancreatic amylase but not into total pancreatic protein. This increase is completely abolished by actinomycin D. Short‐term effects of adrenalectomy (20 h) and effects of substitution with 6‐α‐fluoro‐16α‐methyl‐prednisolon on the incorporation of (4,5‐3H)‐leucine into pancreatic amylase and total pancreatic protein result mainly from changes in the size of the cold leucine pool. According to these results insulin regulates pancreatic amylase synthesis mainly at the level of transcription. Insulin plays a permissive role in pancreatic amylase synthesis and is not involved in short‐term regulation of amylase synthesis in the non‐diabetic state. Clinical findings in juvenile diabetics indicate a similar type of regulation for amylase synthesis.

Amylase changes accompanying stimulated salivary gland growth

The rat's salivary gland histology and amylase activity, as changed by chronically injected pharmacological dosages of a salivary stimulant (isoproterenol) or by dietary supplements of pancreatin, were compared to those of normal animals. Both treatments induced an enlargement of the submaxillary glands and an increase in amylase activity of the gland homogenates. Isoproterenol induced a greater change in the histology of the gland; there was a greater increase in acinar cell size, loss of tubular granulation, and a greater loss of compression of tubules. Similar changes of smaller magnitude were detected in animals receiving dietary supplements of pancreatin. Parotid gland enlargement followed either treatment but isoproterenol caused a decrease in amylase activity of parotid homogenates while pancreatin increased the enzyme's activity. In addition there was a loss of body-weight with pancreatin feeding while none occured with the administration of isoproterenol. Thus a difference in mode of action of the two stimuli seems to result in several differences in physiological response, despite the induction of similar changes in salivary gland growth and histology.

The Effect of 6‐Benzylaminopurine on the Starch Metabolism of Stellaria media

AbstractThe effect of 6‐benzylaminopurine (BAP) was studied by measuring the amylase activity of leaf extracts and the starch content of chloroplasts in Stellaria media‐plants cultivated for five days in solutions containing different quantities of BAP.Small amounts of BAP decreased amylase activity in weak‐growing plants. In strong‐growing ones the effect was variable. However, in all experiments very high amount of this growth regulator caused a great increase in amylase activity which was accompanied by a relatively high concentration of starch in the chloroplasts. The induction of amylase activity was thus not high enough to diminish the starch content. This is supposed to be due to the lack of a sink organ since the growth of roots and shoots was greatly inhibited in concentrated BAP‐solutions (10‐5M or more). In these cases the plants usually died during the first week.In some cases small amounts of BAP increased the growth of S. media, and high concentrations inhibited it causing characteristic morphological changes, such as creeping growth pattern, small, thick leaves and the turning up of the leaf margins.Benzylaminopurine also caused increased resistance to aging, especially in low concentrations (10–7–10–6M).