PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Secretory Rate”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1979

The effects of a high-fiber diet on bile acid pool size, bile acid kinetics, and biliary lipid secretory rates in the morbidly obese.

A high-fiber diet has been suggested as one reason for the low incidence of gallstones in some populations. Therefore the authors tested the effects of a high-fiber diet on biliary secretory kinetics and bile salt kinetics in morbidly obese volunteers. Bile salt pool sizes were reduced by 50%, and their half-lives were decreased 70% after the subjects had spent 6 weeks on the high-fiber diet. Bile acid enterohepatic circulation times also were shortened dramatically. However, the lithogenicity of bile did not decrease, and bile remained supersaturated with with cholesterol. Fasting bile samples tended to be even more lithogenic than before the subjects follwed the diet. In these obese subjects, a high-fiber diet failed to reduce the tendency to secrete cholesterol-saturated bile.

Adult↗
PubMed1977

Uptake of K+ by frog gastric mucosa from submucosal side and acid secretory rate.

The K+ content in frog gastric mucosa (K+) was measured as a function of the submucosal K+ concentration ([K+sm]) in the absence of K+ on the mucosal side. The (K+) in HCO3- buffer with 95% O2-5% CO2 gas showed that the removal of external K+ induced a 27% K+ loss from the control value of 5 mM K+sm, that there was no linear relation between (K+) and [K+sm, and that the change in the (K+) versus the [K+sm] was hyperbolic, indicating that there are two different types of K+ in the mucosa: bound and free K+.

Animals↗
PubMed1978

Endoscopic measurement of pancreatic juice secretory flow rates and pancreatic secretory pressures after secretin administration in human controls and in patients with acute relapsing pancreatitis, chronic pancreatitis, and pancreatic cancer.

Secretory flow rates were measured inside the main pancreatic duct during endoscopic retrograde cholangiopancreatography (ERCP) in patients with acute relapsing pancreatitis, chronic pancreatitis, and pancreatic cancer and in controls after intravenous administration of secretin. Peak secretory flow rates in these groups were 5.04 +/- 1.74, 0.71 +/-1.28, 0.60 +/- 1.37, and 4.13 +/- 0.88 ml/min, respectively. Peak secretory pressures were also measured intraductally in patients with acute relapsing pancreatitis and pancreatic cancer and in controls and were 402 +/- 69, 75 +/- 161, and 403 +/- 99 mm pancreatic juice, respectively. Peak secretory flow rates and pressures measured in controls during constant administration of secretin were similar to those measured when secretin was administered as a bolus.

Endoscopy↗
PubMed1979

Foetal-maternal production and transfer of cortisol during the last days of gestation in the guinea-pig.

The metabolism and the rate of transfer of cortisol across the placenta in pregnant guinea-pigs and foetuses were studied by constant intravenous infusions of tritium-labelled cortisol. Estimates of endogenous and radioactive plasma cortisol levels were used to calculate the following parameters at four stages before parturition (days 62, 64, 66 and 67; parturition occurring at day 68): metabolic clearance rate; production rate; adrenal secretory rate; transfer rate from mother to foetus and from foetus to mother; irreversible removal rate; the fraction of cortisol derived from the other in the foetal and maternal vascular compartments; the fraction of secreted and recycled cortisol involved in the transfer. The metabolic clearance rate and the rates of production and secretion of cortisol were higher in the mother than in the foetus between days 62 and 67 of gestation. About 90% of the foetal cortisol was of maternal origin. The fraction of maternal cortisol of foetal origin increased in the last days of gestation.

Anesthesia↗
PubMed1979

Bradykinin-induced renal hemodynamic alterations: renin and prostaglandin relationships.

The present studies examined the role of the renin-angiotensin system as a modifier of the renal vasomotor response to bradykinin. Renal arterial bradykinin infusion (80 ng.kg-1.min-1) initially resulted in increased renal blood flow (RBF). The secretory rates of renin and prostaglandins increased after 60 min. With continued bradykinin administration (120 min) RBF and prostaglandin secretory rates returned toward control values, although renin secretory rate remained elevated (P less than 0.02). After prostaglandin synthetase inhibition, RBF decreased and bradykinin administration returned RBF to control values. Prostaglandin secretory rates decreased after meclofenamate (P less than 0.005). Continued bradykinin infusion resulted in a return of the renin secretory rate to control values. The administration of bradykinin after competitive inhibition of angiotensin II resulted in a sustained increase in renal blood flow. These results suggest that the initial bradykinin-induced renal hyperemia is only partially dependent on enhanced prostaglandin release, the increase in renin secretion by bradykinin infusion after prostaglandin synthetase inhibition is consistent with a bradykinin and renin interaction, and the lack of a sustained hyperemia after bradykinin is related to increased renin-angiotensin system activity.

Angiotensin II↗
PubMed1978

The distribution and secretion of kallikrein in some exocrine organs of the rat.

Extractable kallikrein was quantitated in the submandibular, sublingual, and parotid glands and in the pancreas. No kallikrein was detected in the exorbital lacrimal glands and tears. The highest kallikrein concentrations (EU/ml) were in all major salivary gland secretions seen after alpha-adrenergic stimulation, less after beta-adrenergic and least after parasympathetic stimulation. When taking into account the large variations in salivary flow rate, alpha-adrenergic stimulation was in the parotid and particularly in the submandibular gland found to result in the highest kallikrein secretory activity measured by the kallikrein secretory rate(EU/min). This shows that the kallikrein-rich granular tubular cells are selectively activated through alpha-adrenergic sympathetic receptors. The differences observed in the parotid saliva were small and not always statistically significant. However, when cervical nerve stimulation was superimposed upon parasympathetic stimulation, kallikrein secretory rate as well as kallikrein concentration increased. The large individual variations in salivary gland kallikrein content and secretion and the rather small differences observed in kallikrein secretory rate after nervous stimulation of the parotid and sublingual glands, may indicate that the kallikrein-containing striated ducts are also influenced by factors other than the secretory nerves. The kallikrein concentration and secretory rate in urine was studied. A strong positive correlation between kallikrein secretory rate and fluid volume was found in urine but not in saliva.

Animals↗
PubMed1977

In vitro measurement of rate of fluid secretion in rat isolated seminiferous tubules: effects of metabolic inhibitors and ions.

1. An in vitro technique for measuring secretory rate in rat isolated seminiferous tubules is described. 2. The basal rate of fluid secretion was 0-44+/-0-06 nl. cm-1 min-1 (S.E.) (n=21). The rate was found to be inhibited by cooling, addition of metabolic inhibitor 2,4-dinitrophenol (2-5 x 10(-4) M) and removal of glucose from the incubating solution. This indicates that fluid secretion in isolated rat seminiferous tubules is an energy dependent process. 3. Removal of K+ from the incubating medium inhibited the secretory rate in the isolated seminiferous tubules, whereas a fivefold increase in [K+]0 to 23-5 mM had no effect. The secretory rate was also unaffected by the absence of Cl- in the peritubular fluid. 4. Removal of Ca2+ from the peritubular medium caused a rise in the secretory rate. 5. Ouabain (10(-3) M) and acetazolamide (4 x 10(-5) M) caused a fall in the rate of fluid secretion in isolated seminiferous tubules. 6. These results are discussed in relation to the nature of the ionic secretion produced in the tubules.

Acetazolamide↗
PubMed1976

[On the significance of beta-adrenergic stimuli for the gastric secretion in humans].

In adults of both sexes, the influence on the basal and the maximal by means of pentagastrin stimulated gastric secretion of a single intravenous injection of 8 mg (0.09 to 0.16 mg/kg) oxyfedrine or of two intramuscular injections of 1 mg (0.014 to 0.016 mg/kg) or of 2.5 mg (0.033 to 0.045 mg/kg) in each case isoproterenol, consecutively administered at an interval of 15 minutes, was studied. At a dose which evokes cardiovascular responses isoproterenol does not produce a significant change of the secretory rates of H+, C1-, Na+, K+, Ca++ and Mg++ or of the ionic composition of gastric juice both during basal and maximal acid output. Oxyfedrine shows only during maximal acid stimulation some effects on gastric secretion: a significant rise of the concentration and secretory rate of H+ and of the secretory rate of C1- and a significant decline of the concentration of Na+ and of both the concentration and secretory rate of Mg++. Beta-adrenergic receptors seem not to play any part in the regulation of the production of gastric juice. Possibly, the action of oxyfedrine on the stimulated gastric mucosa may be mediated by a stimulation of alpha-adrenergic receptors or by inhibition of the activity of 3',5'-AMP-phosphodiesterase.

Adrenergic beta-Agonists↗
PubMed1975

Electrophysiology of the frog gastric mucosa with sufficient CO2.

Changing from 5% CO2 in the serosal solution only to 10% CO2 on both sides doubles the acid secretory rate of the bullfrog stomach (as shown previously) and raises the transmural potential difference, although the short-circuit current is not changed. The secretory overshoot on reoxygenation after anaerobiosis, observed in 5% CO2, is virtually eliminated in 10% CO2, as predicted by the diffusion model which explains the secretory rate increase. It was found that the rate of rise of the secretory rate during anoxia was identical in the 2 conditions, which explains the increased secretory lag in 10% CO2 and suggests an interesting limitation on the rate with which acid secretion can be activated. During anoxia in 10% CO2, but not in 5% CO2, there occurs a sudden drop in PD to a slightly negative value associated with a fall in tissue resistance. This effect occurs under SCN-inhibition and thus seems unrelated to H+ transport per se. A working model is presented which can explain some of the events surrounding the sudden potential drop.

Animals↗
PubMed1976

Progesterone secretion by adrenal glands of hamsters and comparison of ACTH influence in rats and hamsters.

Studies were designed to determine a) if adrenal glands of hamsters secrete progesterone (PROG), b) the effects of adrenocritocotropin (ACTH) administration on adrenocortial function of rats and hamsters under the surgical conditions necessary for collection of adrenal venous blood from the left renal vein, and c) the effects of blood loss during sample collection. PROG was quantitated by the competitive protein-binding method after extraction and separation by sephadex LH-20 column chromatography. The presence of interfering quantities of androstenedione necessitated two column chromatographic steps. Glucocorticoids (11-OHCS) were determined fluorometrically. PROG was detected in adrenal venous plasma of female hamsters. The PROG concentration and secretory rate were 91 +/- 12 ng/ml and 4 +/- 1 ng/min, respectively, while the peripheral plasma level of the same animals was 2 +/- 0.2 ng/ml, indicating that the adrenal glands of female hamsters are capable of secreting PROG. ACTH administration increased PROG secretory rates in both hamsters (3 +/- 1 to 14 +/- 3 ng/min) and rats (62 +/- 9 to 152 +/- 32 ng/min) on estrus, as well as increasing the 11-OHCS secretory rate of hamsters (16 +/- 1 to 33 +/- 4 ng/min), but not of rats. The greater increase in PRCC than in 11-OHCS secretion may be related to excess PROG formation relative to the capacity of the 17alpha- or 21-hydroxylating enzyme systems. The adrenal venous PROG concentration and secretory rate of female hamsters infused with 10% dextran while collecting adrenal venous blood did not differ significantly from those of the non-infused animals, suggesting that this amount of blood loss (1 ml) does not influence PROG secretion.

Adrenal Glands↗
PubMed1975

Oxygenation of frog gastric mucosa in vitro.

We have recently shown that 5% CO2/95% O2 in the serosal bathing solution, with 100% O2 in the mucosal solution, results in CO2-diffusion limitation of acid secretion in bullfrog gastric mucosa. Changing to 10% CO2/90% 02 on both surfaces doubles the acid secretory rate. We calculate that, were the rate of oxygen consumption to increase significantly as a result of secretory stimulation, the tissue would now be oxygen limited. This prediction is tested by raising the P02 by increasing the total pressure in a hyperbaric chamber. Since no change in acid secretory rate or potential difference was observed upon changing from PO2 = 0.9 to PO2 = 1.9 atm, we conclude that the tissue is not O2 limited at normal pressure. Decreasing PO2 below 0.9 atm, by contrast, decreases the acid secretory rate and raises both PD and resistance. We infer that the rate of oxygen consumption did not rise significantly when acid secretion was increased by supplying sufficient CO2.

Animals↗
PubMed1976

A comparative study of adrenal progesterone secretion during the estrous cycles of hamsters and rats.

Adrenal secretory rates and peripheral plasma levels of progesterone (PROG) were determined during the estrous cycles of hamsters and 4-day cyclic rats. In both species, the PROG concentrations in peripheral plasma were never more than 6% of those observed in adrenal venous plasma. In hamsters, adrenal PROG secretory rates varied from 3.8 +/- 0.8 ng/min at 0800 hr on proestrus (P) to 8.5 +/- 1 ng/min at 2000 hr on estrus (E). The rates noted on P were among the lowest observed and were similar to those noted at 0800 hr the following morning. In rats, adrenal PROG secretory rates varied from 57 +/- 9 ng/min at 0800 hr on E to 130 +/- 18 ng/min at 2000 hr on P. A significant decline occurred between 2000 hr on P and 0800 hr the following morning. Rats secreted 3 to 8 times more PROG than did hamsters when the secretory rates are expressed as ng/min/100 mg adrenal. In hamsters, the data suggest a relative lack of influence of female reproductive hormones on adrenal PROG secretion and in turn the latter may not be involved in reproductive hormonal changes leading to ovulation. In rats, the increased adrenal PROG secretion noted on P may be due to the influence of reproductive hormones on adrenocortical function. This elevated rate may in turn influence the hypothalamo-hypophyseal-ovarian axis.

Adrenal Glands↗
PubMed1976

The turnover and distribution of labelled corticosterone during post-natal development of the duckling (Anas platyrhynchos).

During 6 months of post-natal development in the laboratory, the weight of the adrenal gland relative to body weight decreases exponentially. In the 3 day-old duckling a single intravenous dose of labelled corticosterone becomes distributed in a very large apparent volume and an "extracellular" pool that is greater than the extracellular fluid volume and the pattern of disappearance of labelled hormone from plasma is biphasic. Later during development the volumes of distribution decrease and the biphasic pattern of disappearance becomes less distinct until at 6 months only one phase of disappearance can be detected with confidence. No significant change in plasma corticosterone concentration occurs during this period of development in the laboratory. Estimations of the corticosterone secretory rates, however, indicate that whereas the adrenal weight-specific rate os secretion increases during the first 3 weeks and declines therafter, the bodyf weight-specific secretory rate continues to decline throughtout the period of increasing body weight.

Adrenal Glands↗
PubMed1978

Role of aldosterone in the antihypertensive effect of spironolactone in essential hypertension.

In order to evaluate the relationship between aldosterone status and the blood pressure-lowering effect of spironolactone, 38 patients with essential hypertension were treated with spironolactone (400 mg/day) during one week in hospital on a rigidly sodium-restricted diet. The degree of hyperaldosteronism was assessed by the aldosterone secretory rate after 5 days of salt loading (315 mmol Na+/day). The mean arterial pressure decreased 5.6% (range, -21 to +8%). When the patients were divided into subgroups with low and normal renin activity, there was no difference in the change in mean arterial pressure (-5.0% and -6.1%). When the patients were divided into three groups with low, normal, and supranormal aldosterone secretory rates, the last group had a significantly greater fall in blood pressure after the spironolactone than the other groups (-1.0, -7.1, -11.1%). Thus there was a correlation between the aldosterone secretory rate after sodium loading and the blood pressure-lowering effect of spironolactone (r = -0.53, p less than 0.01). The blood pressure-lowering effect was not related to changes in body weight, kidney function, or plasma electrolytes. Our findings do not provide solid arguments for the view that the blood pressure-lowering effect of high dose spironolactone is due to its antimineralocorticoid activity, but the correlation between the degree of hyperaldosteronism and the blood pressure-lowering effect strongly suggests that aldosterone does play a role in the genesis or maintenance of the hypertension in these patients.

Adult↗