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

1985 ◽  
Vol 403 (4) ◽  
pp. 440-445 ◽  
Author(s):  
J. O. Dich-Nielsen ◽  
L. P. Laugesen ◽  
J. Hedemark Poulsen
Keyword(s):  
Flow Rate ◽  
Salivary Secretion ◽  
Perfusate Flow ◽  
Perfusate Flow Rate

Increased flow rate and papaverine increase K+ exchange in perfused rat hind-limb skeletal muscle

1999 ◽  
Vol 77 (7) ◽  
pp. 536-543 ◽  
Author(s):  
Michael I Lindinger ◽  
Thomas J Hawke
Keyword(s):  
Skeletal Muscle ◽  
Flow Rate ◽  
Hind Limb ◽  
Random Order ◽  
Fold Increase ◽  
Muscle Membrane ◽  
Arterial Perfusion ◽  
Hind Limbs ◽  
Perfusate Flow ◽  
Perfusate Flow Rate

This study tested the hypothesis that increases in perfusate flow rate result in increased rates of unidirectional and net K+ transport in rat hind-limb skeletal muscle at rest. Ten neurally and vascularly isolated hind limbs, with arterial and venous catheters placed proximal to the popliteal region, were perfused for 10-min periods at flow rates (presented in a random order) of 0.27, 0.42, 0.63, 0.84, or 1.05 mL·min-1·g-1. Potassium extraction and unidirectional K+ influx were determined using 42K, and arterial perfusion pressure was measured continuously. Increases in flow rate resulted in decreases in K+ extraction and increases in unidirectional K+ influx, unidirectional K+ efflux, and net K+ efflux. The increases in K+ flux were associated with increases in oxygen uptake, glucose uptake, and lactate release. In separate experiments (n = 5), the vasodilator papaverine (10-4 M) did not further vasodilate the vasculature of resting hind limbs, suggesting that the hind limbs in this preparation were fully vasodilated. Papaverine, at constant flow, resulted in a nearly 1.5-fold increase in K+ extraction, a doubling of unidirectional K+ influx, and increases in unidirectional K+ efflux and net K+ efflux. It is concluded that physiological increases in flow rate result in increases in K+ transport in isolated, perfused rat hind-limb skeletal muscle. Furthermore, papaverine appeared to induce an increase in skeletal muscle membrane permeability to K+.Key words: K+ transport, potassium extraction, Na-K ATPase, sarcolemma, plasma flow, vasodilator, VO2.

beta-carotene intestinal absorption: bile, fatty acid, pH, and flow rate effects on transport.

1978 ◽  
Vol 235 (6) ◽  
pp. E686 ◽  
Author(s):  
D Hollander ◽  
P E Ruble
Keyword(s):  
Flow Rate ◽  
Sodium Taurocholate ◽  
Beta Carotene ◽  
Hydrogen Ion ◽  
Absorption Increase ◽  
Perfusate Flow ◽  
Rate Effects ◽  
Rate Of Absorption ◽  
Chain Lengths ◽  
Perfusate Flow Rate

beta carotene absorption in the unanesthetized rat was investigated by recirculating a micellar perfusate that contained beta-carotene through jejunal and ileal intestinal loops. Radioautography revealed extensive distribution of the provitamin throughout the layers of the small bowel. A linear relationship was found between the concentration of beta-carotene in the perfusate and its rate of absorption at perfusate concentrations of 0.5--11 mM. Increases in the perfusate hydrogen ion concentrations, additions of fatty acids of varied chain lengths and degrees of saturation, and an increase in the perfusate flow rate caused higher rates of beta-carotene absorption. Increase in the perfusate sodium taurocholate concentration above 2.5 microM did not change the absorption rate of beta-carotene. These experiments indicate that beta-carotene absorption takes place by passive diffusion. The process of diffusion can be modulated by intraluminal factors that change the physical characteristics of perfusate or stimulate the intracellular cleavage of carotene to retinal.

Effect of blood flow on muscle lactate release studied in perfused rat hindlimb

1995 ◽  
Vol 269 (6) ◽  
pp. E1044-E1051 ◽  
Author(s):  
H. Pilegaard ◽  
J. Bangsbo ◽  
P. Henningsen ◽  
C. Juel ◽  
E. A. Richter
Keyword(s):  
Blood Flow ◽  
Flow Rate ◽  
Minor Importance ◽  
Muscle Lactate ◽  
Lactate Release ◽  
Perfusate Flow ◽  
Supramaximal Stimulation ◽  
The Difference ◽  
Lower Flow Rate ◽  
Perfusate Flow Rate

The influence of blood flow on muscle lactate and H+ release as well as muscle glyconeogenesis was studied in the perfused rat hindlimb. After 2 min of supramaximal stimulation the perfusate flow rate was 7 (F7), 12 (F12), or 18 (F18) ml/min for 30 min. Perfusate samples were drawn frequently and muscle samples were obtained before stimulation, immediately after stimulation, and at 3, 10, and 30 min of recovery from soleus, white gastrocnemius (WG) and red gastrocnemius. During the first 5 min of recovery lactate release was 35-39% lower (P < 0.05) in F7 than in F12 and F18 but with no differences in total release during recovery. In F7 the concentration of lactate was higher (P < 0.05) in soleus after 10 min (18-20%) and in WG after 30 min (63-67%) than in F12 and F18. During the first 2 min of recovery H+ release was 23-34% lower (P < 0.05) in F7 than in F12 and F18. The difference between H+ and lactate release was larger (P < 0.05) in F7 than in F12 and F18 from 3 to 10 min and from 5 to 10 min of recovery, respectively. Muscle glycogen concentrations after 30 min of recovery were independent of flow in each of the muscles. The present data suggest that 1) in the range of blood flow rates from 0.61 to 0.92 ml.min-1.g-1, lactate and H+ release are independent of the flow rate, whereas at a lower flow rate (0.36 ml.min-1.g-1) release of these substances is decreased; 2) low blood flow influences lactate efflux more than H+ release; and 3) muscle glyconeogenesis from lactate is of minor importance.

Tissue pressure and autoregulation in the dextran-perfused kidney

1959 ◽  
Vol 197 (4) ◽  
pp. 853-855 ◽  
Author(s):  
Lerner B. Hinshaw ◽  
Henry M. Ballin ◽  
Stacey B. Day ◽  
Curtis H. Carlson
Keyword(s):  
Arterial Pressure ◽  
Renal Artery ◽  
Flow Rate ◽  
Volume Changes ◽  
Homologous Blood ◽  
Tissue Pressure ◽  
Vascular Volume ◽  
Perfusate Flow ◽  
Perfusate Flow Rate ◽  
Autoregulation Of Flow

Experiments were performed on isolated dog kidneys alternately perfused with homologous blood and dextran. Renal artery pressure, tissue pressure, perfusate flow rate and vascular volume changes were measured as arterial pressures were progressively elevated. Marked increases in overall vascular resistance RA/F occurred in all dextran- and blood-perfused kidneys throughout the autoregulatory range. Results indicate that autoregulation of flow occurs in both blood- and dextran-perfused kidneys concurrent with increases in tissue pressure. Dextran- and blood-perfused kidneys show similar degrees of autoregulation when values are expressed in terms of increase in flow per unit rise of arterial pressure and compared to preautoregulation values.

Effects of flow and contraction on lactate transport in the perfused rat hindlimb

1994 ◽  
Vol 267 (1) ◽  
pp. E7-E13 ◽  
Author(s):  
P. W. Watt ◽  
L. B. Gladden ◽  
H. S. Hundal ◽  
R. E. Crawford
Keyword(s):  
Electrical Stimulation ◽  
Lactate Concentration ◽  
Lactate Production ◽  
Tracer Technique ◽  
Lactate Transport ◽  
Muscle System ◽  
Flow Rates ◽  
Perfusate Flow ◽  
Perfusate Flow Rate ◽  
Dual Tracer

A perfused rat hindlimb preparation was used to assess the effects of perfusate flow and electrical stimulation to mimic exercise on the rates of lactate influx (measured by a dual tracer technique with [3H]mannitol as the extracellular marker) and net lactate production. The same perfused muscle system was also used for assessing the effects of alpha-cyano-4-hydroxycinnamate (CIN, 15 mM), phloretin (0.6 mM), and pyruvate on tracer lactate influx. Unidirectional lactate influx, oxygen uptake (VO2), and net lactate flux were all significantly dependent on perfusate flow rate (all P < 0.05). The hindlimb was in net lactate production at all flow rates studied. Electrical stimulation (60 Hz, 100 ms, 20 V trains at 0.6 min-1) at perfusate lactate concentration of 1 mM significantly increased the hindlimb VO2 from 8.0 +/- 1.1 to 16.0 +/- 2.2 ml.kg-1.min-1 and production of lactate from -69 +/- 31 to -823 +/- 77 nmol.min-1.g-1 (both P < 0.001) but did not affect tracer-measured unidirectional lactate influx (nonstimulated: 235.4 +/- 78.1; stimulated: 235.0 +/- 31.0 nmol.min-1.g-1). At a perfusate flow of 0.55 ml.g-1.min-1 the unidirectional influx of 1 mM lactate was markedly inhibited (90 +/- 5%) by 15 mM CIN. CIN also significantly reduced VO2 from 6.2 +/- 0.16 to 4.45 +/- 0.57 ml.kg-1.min-1 (P < 0.05, n = 5). Phloretin (0.6 mM, n = 3) had no significant effect on lactate influx.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Effect of lemon on saliva and Staphylococcus aureus

2019 ◽  
Vol 31 (2) ◽  
pp. 85
Author(s):  
Natasya Angelyna Batubara ◽  
Yumi Lindawati
Keyword(s):  
Staphylococcus Aureus ◽  
Flow Rate ◽  
Test Group ◽  
Salivary Flow ◽  
Salivary Secretion ◽  
Lemon Juice ◽  
Salivary Flow Rate ◽  
Wilcoxon Test ◽  
Mannitol Salt Agar ◽  
Salivary Ph

Introduction: Lemon juice contains citric acid. It is a highly antibacterial organic acid by gargling with, will be able to decrease the spreading of Staphylococcus aureus colony in saliva. The acid stimulation of lemon juice able to increase salivary secretion. The purpose of this study was to see the effect of gargling lemon juice of 100%, 50%, 25%, and 12.5% concentrations towards the salivary flow rate, salivary pH, the number of Staphylococcus aureus colony, and also, correlation between salivary flow rate and pH, salivary flow rate and number of Staphylococcus aureus colony, and salivary pH and number of Staphylococcus aureus colony. Methods: This research conducted with a pre-and-post-test group design. Saliva was taken from 24 subjects before and after the subjects gargled with lemon juice. Measurements performed were salivary flow rate per minute, and salivary pH (using pH Hanna Instrument). The Staphylococcus aureus bacteria were placed in a Mannitol Salt Agar for 24 hours at 370C temperature, then the number of the colonies were counted (x103 CFU). Results: The Wilcoxon test results showed that lemon juice with 100%, 50%, 25%, and 12.5% concentrations significantly increased the salivary flow rate and decreased the number of Staphylococcus aureus colony (p < 0.05). The result of the paired t-test showed that lemon juice with 25% and 12.5% concentration decreased the salivary pH significantly (p<0,05). The Pearson’s correlation results showed no significant correlation between salivary flow rate and salivary pH, flow rate and the number of Staphylococcus aureus colony, and salivary pH and number of Staphylococcus aureus colony. Conclusion: Lemon juice can decrease the salivary pH and the number of Staphylococcus aureus colony, but increases the salivary flow rate. It is considered to be good enough as one of the ingredients of mouthwash.Keywords: Flow rate, lemon, pH, saliva, Staphylococcus aureus

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