Secretory Flow Rate Research Articles

A novel diagnostic technique of measuring labial minor salivary gland secretions using sodium fluorescein dye: Implications for patients with dry eyes

ABSTRACT Purpose: To evaluate the lower labial minor salivary glands (MSGs) flow rate using fluorescein dye in healthy individuals and patients with Sjögren’s syndrome (SS) and Stevens–Johnson syndrome (SJS). Methods: Thirty consecutive patients with SS (N = 15; mean age 35.7 years) and SJS (N = 15; 57.7 years), and their age- and sex-matched healthy controls (N = 40; mean ocular surface disease index (OSDI) = 6.1) had ocular examination and whole lower labial mucosa evaluation after ophthalmic fluorescein strip application under cobalt blue light. Analyzed parameters include average labial distribution of functional MSGs, their secretory flow rate, and comparison between healthy and diseased groups. Results: The mean salivary flow rate from the lower labial MSGs of normal individuals showed decade-wise decline (2.7 ± 0.29 l/min, 2.6 ± 0.39 l/min, 2.3 ± 0.6 l/min, 1.9 ± 0.95 l/min) with similar trend for the number of secreting MSG openings (38.7, 37.2, 30, 22). The mean OSDI score was 45.3 in SJS and 28.2 in SS group. Thirty eyes in each SS and SJS group had mean Schirmer I value of 1.5 ± 2.2 mm and 5.1 ± 4.4 mm. The mean lower labial salivary flow rate in SS group was 0.5 ± 0.28 l/min, and 2.0 ± 0.95 l/min in SJS group. When compared to normal, SS patients had a significant reduction in the flow rate (p < .00001); however, it was not significant for the SJS group (p = .28). The mean number of secreting MSG openings was reduced in both the groups compared to normal (SJS, 20.5; p = .01 and SS, 12; p < .0001). There was a significant difference between SS and SJS groups in terms of flow rate (p < .00001) and number of MSG openings (p = .001). The MSG flow rate and Schirmer values did not show any correlation in SS or SJS patients. Conclusion: The fluorescein-assisted evaluation of the lower lip can be used as a quantitative method for measuring the labial salivary flow rate in SS and SJS patients.

Role of Endoscopic Retrograde CholangioPancreatography (ERCP) and Intraductal Secretin Test (IDST) in the Diagnosis of Chronic Pancreatitis (CP)

Background: &#x0D; CP may be difficult to diagnose in the early stages when imaging may be normal. An IDST performed at ERCP may further evaluate for CP, with determination of pure pancreatic juice (PPJ) volume and bicarbonate concentration (BC). The optimal collection time for IDST is unknown. We report our experience with the IDST in 447 patients with suspected CP. &#x0D; Experimental Design: &#x0D; IDSTs performed from 2006-2018 were reviewed, with fluid collected at 5-min intervals for 20-60 minutes. Parameters evaluated were PPJ volume, Secretory Flow Rate (SFR), time of peak SFR, maximum BC and time to maximum BC. &#x0D; Results: &#x0D; Maximum BC was reached by 10-min in 59 patients (13.2%); 15-min: 207 patients (46.3%); 20 min: 340 patients (76.1%); 25-min: 384 patients (85.9%); 30-min: 421 patients (94.1%). Peak SFR was reached by 10-min in 92 patients (20.6%); 15-min: 177 patients (39.6%); 20-min: 240 patients (53.7%); 25-min: 284 patients (63.5%); 30-min: 323 patients (72.3%). Final diagnosis (normal vs. CP) for both SFR and BC was determined by 20-min (i.e. in CP pts, either the SFR or BC was low (SFR &lt;3ml/min, BC &lt;105mEq/L) and remained low throughout collection, or normal (&gt;3ml/min and &gt;105mEq/L) within the first 20-min. Further collection did not change the diagnosis. &#x0D; Conclusion: &#x0D; At IDST, a 20-minute collection period is necessary to categorize patients into normal or suspected CP groups. A study in control patients (no suspicion of CP) to validate these data is currently underway.

Autonomic reinnervation and functional regeneration in autologous transplanted submandibular glands in patients with severe keratoconjunctivitis sicca

Autologous submandibular gland (SMG) transplantation has been proved to ameliorate the discomforts in patients with severe keratoconjunctivitis sicca. The transplanted glands underwent a hypofunctional period and then restored secretion spontaneously. This study aims to investigate whether autonomic nerves reinnervate the grafts and contribute to the functional recovery, and further determine the origin of these nerves. Parts of the transplanted SMGs were collected from the epiphora patients, and a rabbit SMG transplantation model was established to fulfill the serial observation on the transplanted glands with time. The results showed that autonomic nerves distributed in the transplanted SMGs and parasympathetic ganglionic cells were observed in the stroma of the glands. Low-dense and unevenly distributed cholinergic axons, severe acinar atrophy and fibrosis were visible in the patients’ glands 4–6 months post-transplantation, whereas the cholinergic axon density and acinar area were increased with time. The acinar area or the secretory flow rate of the transplanted glands was statistically correlated with the cholinergic axon density in the rabbit model, respectively. Meanwhile, large cholinergic nerve trunks were found to locate in the temporal fascia lower to the gland, and sympathetic plexus concomitant with the arteries was observed both in the adjacent fascia and in the stroma of the glands. In summary, the transplanted SMGs are reinnervated by autonomic nerves and the cholinergic nerves play a role in the morphological and functional restoration of the glands. Moreover, these autonomic nerves might originate from the auriculotemporal nerve and the sympathetic plexus around the supplying arteries.

Intraductal Secretin Stimulation Test: What Is the Proper Collection Time?

Pancreatic function tests are helpful methods to establish or exclude a diagnosis of chronic pancreatitis (CP). Many studies confirm the clinical utility of the intraductal secretin test (IDST), and that the most discriminatory parameters used are secretory flow rate (SFR) and bicarbonate concentration (BC)∗. Forty-five minutes (min) IDST collection time was recommended by some investigators. A shorter collection time has been proposed to increase the practicality of the IDST, but the precise time has been not well defined. The aim of our study is to establish the IDST proper collection time. Method: The results of 68 IDSTs done in our center were evaluated. Pure pancreatic juice (PPJ) was collected after an IV injection of 16 μg of synthetic secretin (SecreFlo, ChiRhoClin, Inc, Burtonsville). The first 5-min collection was discarded and the PPJ was then collected at 5 minutes intervals up to 45 min. A triple lumen manometry catheter was used to collect the PPJ. The parameters evaluated were the peak SFR, time of peak SFR, max BC (measured by back titration), and time of max BC. Normal SFR was defined as ≥3 ml/min and normal BC was defined as ≥105 mEq/L∗. Results: Max BC was reached by the collection time of 6-10 min in 11 patients (pts) (16%), by 11-15 min in 43 pts (63%), by 16-20 min in 60 pts (88%), by 21-25 min in 65 pts (95%) and by 26-30 min in all pts (100%). Peak SFR was reached by the collection time 6-10 min in 24 pts (36%), by 11-15 min in 37 pts (55%), by 16-20 min in 52 pts (77%), by 21-25 min in 57 pts (84%) and by 26-30 min in all pts (100%). However, all pts reached their final diagnostic classification (normal versus CP) for both the SFR and BC by 20 min collection period [i.e. either the SFR was low (<3 ml/min) from the beginning and remained low throughout the collection time, or normal (≥3 ml/min) within the first 20 min collection time; the same was seen for BC]. Further collection time did not change their final diagnosis. Based on BC criteria, 15 pts had CP (22%). Based on SFR criteria, 31 pts had CP (45%), by either criteria 45% had CP. Summary: The final clinical diagnosis of CP was established or excluded by the first 20 min collection period (for both SFR and BC) in all pts. Conclusions: The first 20-minute collection period during IDST was sufficient time for diagnosing or excluding CP in all pts in this series. This data confirms prior studies showing adequacy of 15-20 min IDST collection time.∗∗Sivak M. Gastroenterologic Endoscopy. 2nd W.B. Saunders Company, 2000:1116-1118.

Effect of High-Intensity Intermittent Exercise on Secretory IgA Response and Salivary Flow Rate

Effect of High-Intensity Intermittent Exercise on Secretory IgA Response and Salivary Flow Rate

Blockade and recovery of cholinergic transmission in rats treated with hemicholinium 3

Nerve-induced responses of parotid gland and gastrocnemius muscle were reduced by HC-3 (1 mg kg −1) in proportion to the number of stimuli. Contractions by somatic muscle at 100 Hz were abolished after 6.0 × 10 3 stimuli while 14 × 10 3 were applied at 20 Hz before secretion was blocked. As stimulus rate was decreased, blockade of secretion resulted from fewer stimuli but no difference in ACh content was found between stimulated and unstimulated glands. When stimuli were withheld for 1.5 h transmission recovered temporarily; initial secretory flow rate was only 50% of that in untreated controls when stimulation resumed. In both organs, the time during which responses were sustained, however, was much shorter than when the preparations were stimulated initially. After choline, recovery of transmission was dose-dependent: 150 mg kg −1 were required to restore responsiveness to the muscle and the gland comparable to that in HC-3-treated rats stimulated for the first time. Resting recovery, when stimuli are withheld, probably depends upon stored transmitter becoming mobilized rather than on de novo transmitter synthesis because the endogenous choline in plasma is only 1/1000 of that following exegenous choline.

Transepithelial transport of nonelectrolytes in the rabbit mandibular salivary gland.

The characteristics of nonelectrolyte secretion by the rabbit mandibular salivary gland have been investigated in an in vitro, perfused preparation. The concentrations of 14C-labeled nonelectrolytes were measured in saliva samples collected over a range of flow rates during the secretory response of the gland to continuous acetylcholine infusion. Of the nine nonelectrolytes studied, the two particularly lipid-soluble molecules, ethanol and antipyrine, appeared in the saliva at approximately the same concentration as in the perfusate, regardless of the secretory flow rate. The more polar molecules (urea, ethanediol, thiourea, glycerol, erythritol, mannitol and sucrose) appeared at saliva/perfusate concentration ratios (phi) which showed a strong dependence on flow. With the exception of thiourea, this could be attributed to the combined contributions of diffusion and solvent drag. For the polar nonelectrolytes, estimates have been obtained of both the permeability coefficients of the gland (P) and the solvent-drag filtration coefficients (1 - sigma). The relation between 1 - sigma and molecular radius suggests that small polar nonelectrolytes and the bulk of the secreted water cross the epithelium via aqueous channels that are approximately 0.8 nm in width. The location of the channels remains uncertain because tissue space measurements indicate that the nonelectrolytes most affected by solvent drag have access to both transcellular and paracellular pathways.

Submandibular salivary secretion in the cat and associated potassium movements: dependence on temperature and perfusate flow rate.

Cat submandibular glands were perfused with Locke solution in a thermostated chamber and intermittently stimulated with 10(-5)M acetylcholine (ACh). In one series of experiments the perfusion pressure was varied within the range 90-60 mm Hg, and secretory flow rate, active K+-reuptake, passive K+-release, and resting and ACh-induced venous flow rates were measured. The ACh-induced secretory flow rate and the maximal K+-fluxes were related to the simultaneous ACh-induced venous flow rates. A proportionality was found between the maximal rate of ACh-induced K+-release and ACh-induced venous flow rates below 8 ml/min, while at higher flow rates the K+-release leveled off. The maximal rate of the post-stimulatory K+-reuptake increased proportionally to the ACh-induced perfusate flow rate throughout the range studied. The secretory flow rate was much less affected by changes in ACh-induced perfusate flow rate. In another series of experiments the gland temperature was varied within the range 12-37 degrees C, and the same parameters were measured. All parameters decreased with cooling being reduced to 50% of their 37 degrees C values at: 24 degrees C for secretion, 19 degrees C for K+-reuptake, and 14 degrees C for K+-release. It is concluded: that the rate of ACh-induced K+-release is limited by the ACh-induced perfusate flow rate (within the physiological range), the capacity of the K+-reuptake mechanism is at least one order of magnitude larger than the maximal rate of K+-reuptake in vivo, the marked temperature sensitivity of the secretory flow rate reflects the high complexity of the mechanisms involved.

Secretion and Electrical Activity of a Unilateral in Vitro Gastric Mucosa

An in vitro unilateral preparation of gastric mucosa is described in which only the serosal side is bathed with a nutrient solution. The preparation permits direct measurement of secretory flow rate and ionic concentration and a continuous recording of transmucosal potential difference. Analysis of amphibian secretion obtained in this manner disclosed striking similarities to the in vivo mammalian secretion. Thus, [Na] and [H] varied inversely, while [K] and [H] varied directly. Secretion became hypo-osmotic at intermediate acidities, but tended to osmotic equilibrium at high flow rates. Neither the early [K] transients nor the late decline in [K] were observed in vitro. The transmucosal potential difference, after correction for junction potentials, was shown not to have altered with the development of secretion. With recent developments in the study of mammalian gastric secretion in vitro, this technique can now be adapted to the direct study of mammalian active and passive secretory mechanisms.

Influence of amphotericin, amiloride, ionophores, and 2,4-dinitrophenol on the secretion of the isolated cat's pancreas.

The isolated cat pancreas was perfused with a Krebs-Henseleit-solution containing different concentrations of Amphotericin, Amiloride, Gramicidin, Dinitrophenol, Valinomycin, and Nigericin. In order to separate functionally the effects of these substances on the mitochondrial and the plasma membrane, we tested their influence on the secretory flow rate under aerobic and anaerobic conditions. A Na+−K+- and a HCO3 −-ATPase have been found in membrane fractions of pancreatic homogenates. Since there is a possibility that these enzymes are involved in active ion transport, we tested the effect of all substances on the level of activity of both Na+K+-ATPase and HCO3 −-ATPase. The following were found: All tested substances except Gramicidin had an effect on pancreatic electrolyte secretion. Concerning the aerobic experiments, the inhibitory effect of Dinitrophenol and the ionophores might be due to uncoupling of oxidative phosphorylation. The results of the anaerobic experiments are interpreted as being due to changes of cell membrane permeability. As the effects of Nigericin, Valinomycin and Amiloride in the anaerobic experiments correspond to the effects of these substances on the ATPase activity, we suggest that these enzymes might be involved in the active transport processes of NaHCO3 −-secretion.

The variability of the human parotid flow rate on stimulation with citric acid, with special reference to taste

In a multifactorial analysis, individual variations in the secretory flow rate of the parotid gland were studied. In all, the effect of 30 different factors on the rate of secretion after stimulation with different citric-acid solutions was studied simultaneously. These factors were general health variables, case history and clinical variables relating to the salivary glands and the oral cavity, sialographic variables and taste. The study showed that the best predictor of secretory capacity of the parotid gland is its size. Of minor importance for the variation of the secretion are sex, weight, the amount of globulin and albumin in blood serum and individual differences in the subjective experience of the acidity of the stimulus. The importance of the size of the glands for the variability of the salivary secretion is so great that a meaningful assessment of the results of sialometric studies is not possible without taking this variable into account. The study includes a description of a radiographic method for the determination of the relative size of the parotid gland.

Flow rate and cation concentration in salt gland secretion of the glaucous-winged gull, Larus glaucescens

1. 1. The sodium and potassium concentrations of 118 NaCl-induced salt gland secretion samples of the gull, Larus glaucescens, were analyzed as functions of secretory flow rate. 2. 2. Sodium concentration was positively correlated with flow rate; potassium concentration was negatively correlated. These relationships were not noted in birds drinking fresh water. 3. 3. The slope of the sodium regression line was little affected by drinking-water salinity, while that of potassium was greatly steepened.