Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: DrugBank:EXPT02427 (Atropine)
 3,300 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Stimulation of alpha-adrenergic and muscarinic cholinergic receptors in rabbit ileal mucosa in vitro produced 5- to 15-fold increases in cyclic GMP (cGMP) concentration that were maximal within 2 min and gone within 30 min. Cholecystokinin octapeptide and insulin caused similar increases in cGMP. None of these agents affected cAMP. The epinephrine-induced increase in cGMP was blocked by atropine at 100 but not at 1 muM concentration. Epinephrine stimulates active NaCl absorption and decreases short-circuit current (SCC) in vitro, the latter effect due to inhibition of HCO3 secretion. Atropine (100 muM) blocked the former but not the latter effect of epinephrine. In vitro additions of several concentrations of cGMP and 8-bromo-cGMP did not decrease SCC or alter Na fluxes. Thus, changes in cGMP concentration have been directly correlated with changes in active absorption of NaCl, but a causal relationship has not been proven.
 ...
PMID:Intestinal mucosal cyclic GMP: regulation and relation to ion transport. 18 10

In rats given a copper-deficient diet plus penicillamine to destroy the acinar tissue selectively, the sensitivity and secretory pattern of pancreatic duct cells to a variety of hormones has been investigated. Resting flow rate of this pancreatic duct model was in the same range as in the intact gland. The duct cells responded to increasing doses of secretin by producing more juice with increasing outputs of bicarbonate, sodium, potassium, and chloride. Bicarbonate concentration increased with the lowest dose of secretin up to values of 64 mEq per liter and did not further increase with higher doses of secretin and increasing secretory rates. The concentration of potassium increased with increasing doses of secretin and flow rates, whereas chloride concentration decreased in a reciprocal fashion to bicarbonate. Gastrin and cholecystokinin-pancreozymin did not significantly stimulate the duct cells. Atropine did not inhibit the action of secretin on the flow rate or on bicarbonate secretion.
 ...
PMID:Pancreatic duct cells in rats: secretory studies in response to secretin, cholecystokinin-pancreozymin, and gastrin in vivo. 90 83

The effects of parenteral pilocarpine, atropine, and norepinephrine on salt and water transport were studied in jejunum and ileum of anesthetized rats. Pilocarpine increased jejunal transmural PD, reduced absorption of Na, K, HCO3, and H2O, and increased secretion of Cl; in ileum, it caused secretion of Na and H2O, elicited secretion of K, and reduced the absorption of Cl. In both segments, perfusate became more akaline, and there was less of a rise in PCO2. Atropine prevented all changes caused by pilocarpine. Atropine alone increased jejunal absorption of Na and HCO3 and acidity of perfusate, implying that cholinergic nerves influence transport. Norepinephrine augmented jejunal absorption of Na, Cl, and H2O but caused no change in PD. In ileum, norepinephrine increased absorption of Na and Cl, reduced the rise in pH, increased the rise in PCO2 of perfusate, but did not affect net HCO3 movement. With all agents, when Na absorption increased, perfusate became more acidic in jejunum and less alkaline in ileum, evidence of an association between Na and H transport.
 ...
PMID:Intestinal ion transport: effect of norepinephrine, pilocarpine, and atropine. 96 67

The exocrine function of healthy pancreas was studied continuously during 9 days in a 28-year-old man. Pancreatic juice was collected by means of a drain passed into Wirsung's duct. The 24-hour volume of the juice was 1118 +/- 117 ml. In daytime the mean rate of juice secretion was 56 ml/hour and in the night it decreased to 20 ml/hour. Amylase and lipase activity in the pancreatic juice was very high and significantly higher in nocturnal secretion. Administration of 2% HCL or secretin (1.5 mu/kg) increased the volume of juice by 30 ml in the following hour without changes in the activities of amylase and lipase. Atropine ephedrine and pancreatin reduced the juice volume by 20-40 ml but the enzymatic acitivity decreased only after atropine. The rise in the juice volume was associated with an increase in its HCO3 concentration and a fall in CL- concentration. The levels of Ca++, K+ and Na+ as well as protein were also determined and it was found that protein concentration in the juice ranges from 0.1 to 4.1 g/100 ml.
 ...
PMID:Studies on the exocrine function of healthy human pancreas: pancreatic juice and its certain components. 98 14

The objective of this study was to assess the changes in outcome of cardiac arrest due to ventricular fibrillation, asystole and electromechanical dissociation in relation to the changing guidelines for drug therapy set by the U.K. Resuscitation Council. It was a retrospective study of 667 resuscitation records for the years 1982, 1986, 1988, 1989, 1990 and 1991. It took place in a large district general hospital with a regional cardio-thoracic centre. We have audited the asystolic cardiac arrests (N = 271) which occurred outside the cardiac care unit (CCU). Adrenaline (intravenous 1 mg) is now the first line drug followed by atropine at an increased dose (2 mg intravenously); calcium is no longer recommended and sodium bicarbonate should be reserved for cases in which an acidosis has been documented. Atropine use has increased over the 9-year period. Bicarbonate use did not change from 1982 to 1986 but fell progressively to no use at all in 1991. Calcium use has declined since 1982. Adrenaline use has remained unchanged. Survival from asystolic arrests (hospital discharge) has remained unchanged at 0-5.5%. Asystole as a primary event in the CCU was uncommon (N = 17) and no patient was discharged. Over the same period, 60% of patients (N = 92) with a cardiac arrest on CCU due to ventricular fibrillation (VF) were discharged and 55% were alive after 6 months. For VF on the wards (N = 192), only 20% of patients were discharged from hospital. A similar proportion was successful for each year.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:An audit of drug usage for in-hospital cardiopulmonary resuscitation. 133 43

The effect of cholinergic agents on proximal tubular absorption of bicarbonate and fluid were examined to investigate the possible role of the cholinergic receptor in the regulation of renal function. Proximal convoluted tubule (PCT) and peritubular capillaries were perfused with bicarbonate-Ringer's solution containing radioactive inulin. Bicarbonate (total CO2) was determined by microcalorimetry. The rates of bicarbonate absorption (JHCO3) and fluid absorption (Jv) were 143.3 +/- 7.2 pEq/min.mm and 2.52 +/- 0.23 nl/min.mm, respectively. Addition of carbachol (10(-8) M) to the capillary perfusate reduced JHCO3 by 17% and Jv by 32%. A higher dose of carbachol (10(-6) M) did not further inhibit JHCO3 or Jv. Simultaneous perfusion of atropine (10(-5) M) together with carbachol (10(-8) M) abolished the inhibitory effect of carbachol on PCT transport. Atropine itself, however, had no effect on PCT transport. The inhibitory effect of carbachol was also diminished by lanthanum chloride (10(-4) M). Carbachol (10(-6) M) had no effects from the luminal side. W-7, a calmodulin antagonist, inhibited carbachol-induced effects. Ionophore A-23187 also inhibited Jv and JHCO3. However, there was no additive effect when A-23187 and carbachol were combined in the capillary perfusate. These results suggest that there are functional cholinergic receptors on the basolateral side of the PCT that can regulate JHCO3 and Jv. Calcium influx may play a role in mediating the cholinergic effects on PCT transport.
 ...
PMID:Cholinergic effect on rat proximal convoluted tubule. 210 2

The effects on pancreatic responses of highly potent cyclic hexapeptide (cyclo (N-Me-Ala-Phe-D-Trp-Lys-Thr-Phe)) (Veber analog) and octapeptide analogs of somatostatin such as D-Phe-Cys-Phe-D-Trp-Lys-Thr-Cys-Thr-ol (SMS 201-995), D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Thr-NH2 (RC-121), and D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Trp-NH2 (RC-160) have been compared with somatostatin tetradecapeptide (SS-14) and atropine. The parameters evaluated were pancreatic responses to secretin and meat feeding in conscious dogs with chronic pancreatic fistula and amylase release from the dispersed pancreatic acini. The analogs were administered intravenously or intraduodenally. The cyclic hexapeptide and octapeptide analogs, given iv in graded doses against a constant background stimulation with secretin, produced similar and dose-dependent inhibition of pancreatic HCO3- and protein secretion. Analogs RC-121, RC-160, and the Veber analog were about two to four times more active than SS-14 in suppressing HCO3- secretion and equipotent in reducing protein secretion, but SMS 201-995 was only about half as potent as somatostatin in inhibiting HCO3-. RC-160 was effective in inhibiting secretin-induced protein secretion at lower doses than other analogs. In tests with feeding, SMS 201-995, the Veber analog, RC-121, and RC-160 were more potent inhibitors of exocrine pancreatic secretion of HCO3- and protein and exhibited more prolonged inhibitory effects than SS-14. The Veber analog, RC-121, and RC-160 were also more effective after intraduodenal administration. Atropine also caused significant inhibition of both HCO3- and protein responses to secretin and meal feeding. All four analogs decreased the postprandial insulin and pancreatic polypeptide release to a similar degree as SS-14. Neither SS-14 nor the analogs tested significantly affected basal or caerulein-, gastrin-, secretin-, or bethanechol-stimulated amylase release from the dispersed canine pancreatic acini. Atropine reduced amylase release induced by bethanechol, but not that stimulated by caerulein, gastrin, or secretin. This indicated that the analogs, as somatostatin, are ineffective as secretory inhibitors in vitro. We conclude that cyclic hexapeptide and octapeptide analogs are more potent and longer acting inhibitors of pancreatic secretion than somatostatin-14 in vivo.
 ...
PMID:Comparison of somatostatin and its highly potent hexa- and octapeptide analogs on exocrine and endocrine pancreatic secretion. 244 2

Distension induces secretion in the intact intestine, but the mechanism of this secretory process remains unresolved. We sought to characterize the effect of intraluminal pressures below 20 cmH2O on water and electrolyte movements in the rat ileum and the subsequent effects of two cholinergic antagonists, hexamethonium and atropine. An increase in intraluminal pressure from 3.0 to 12.5 cmH2O led to inhibition of net H2O and Na absorption and stimulation of HCO3 secretion. However, there was no significant change in Cl absorption. Secretion occurred in the absence of changes in tissue wet weight, intercellular fluid accumulation, villus tip erosions, or mannitol flux. Alterations in fluid and electrolyte absorption were prevented by the intra-arterial administration of hexamethonium (10 mg/kg). Atropine (0.5 mg/kg) had no effect. Our studies demonstrate that distension induces the secretion of Na and HCO3 by the intact ileum. This secretory process may represent a neurally rather than passively mediated mechanism.
 ...
PMID:Induction of neurally mediated NaHCO3 secretion by luminal distension in rat ileum. 256 30

The present study was designed to examine the influence of the vagal nerves on mucosa protective duodenal HCO3(-)-secretion in chloralosed rats. The HCO3(-)-secretion was measured by in situ titration in a duodenal segment devoid of Brunner glands. Cervical vagotomy lowered duodenal HCO3(-)-secretion and stimulation of the cut vagal nerves (10 Hz for 15 min) increased this secretion. Both basal and vagally stimulated duodenal HCO3(-)-secretions were more pronounced in rats with ligated adrenal glands. Atropine did not influence basal duodenal HCO3(-)-secretion, whereas indomethacin and hexamethonium lowered basal secretion in vagotomized rats with ligated adrenal glands. Compared with untreated controls, vagally induced secretory responses were unchanged by atropine, 50% smaller in indomethacin treated rats and almost abolished in rats treated with hexamethonium. The study suggests that the vagal nerves exert an excitatory effect on duodenal HCO3(-)-secretion which is mainly mediated via nicotinic, non-muscarinic transmission, in part dependent on prostaglandin synthesis. Furthermore, the results indicate that the adrenal glands exert an inhibitory action on both the basal and vagally induced mucosa protective HCO3(-)-secretion.
 ...
PMID:Vagal stimulation of duodenal HCO3(-)-secretion in anaesthetized rats. 287 85

The role of gut hormones, such as secretin and CCK, in the stimulation of pancreatic secretion by duodenal HCl or oleate and by meat feeding has been studied in conscious dogs before and after pretreatment with atropine and somatostatin. Plasma hormones were measured by specific and sensitive radioimmunoassays. Duodenal perfusion with HCl and oleate stimulated dose-dependently pancreatic HCO3 and protein secretion and raised plasma levels of secretin and CCK, respectively. Atropine reduced significantly both HCO3 and protein secretion but did not affect plasma secretin and CCK levels in these studies. Both exocrine pancreatic secretion and plasma secretin and CCK levels were suppressed by somatostatin. Meat feeding caused a marked pancreatic HCO3 and protein secretion accompanied by a significant increase in plasma secretin and CCK which seem to play an important role in the postprandial pancreatic stimulation. Both atropine and somatostatin reduced the pancreatic secretion induced by exogenous hormones but only somatostatin, but not atropine, significantly decreased plasma secretin and CCK responses to intestinal stimulants. We conclude that both atropine and somatostatin reduce the pancreatic responses to duodenal HCl or oleate or to meat feeding but only somatostatin is capable of suppressing the release of secretin and CCK.
 ...
PMID:Role of secretin and CCK in the stimulation of pancreatic secretion in conscious dogs. Effects of atropine and somatostatin. 289 Jun 95


1 2 Next >>