scholarly journals A Multi-Parametric Islet Perifusion System within a Microfluidic Perifusion Device

10.3791/1649 ◽  
2010 ◽  
Author(s):  
Adeola F. Adewola ◽  
Yong Wang ◽  
Tricia Harvat ◽  
David T. Eddington ◽  
Dongyoung Lee ◽  
...  
Keyword(s):  
Perifusion System

The depressing (negative) effect of oestradiol benzoate on the in vitro secretion of LH and FSH by the pituitary gland of the LRH-pretreated long-term ovariectomized rat changes into the augmentative (positive) effect after discontinuation of the LRH-pretreatment

1985 ◽  
Vol 110 (3) ◽  
pp. 329-337 ◽  
Author(s):  
G. A. Schuiling ◽  
H. Moes ◽  
T. R. Koiter
Keyword(s):  
Depressing Effect ◽  
Ovx Rats ◽  
Gonadotrophin Secretion ◽  
Oestradiol Benzoate ◽  
Negative Effect ◽  
Positive Effect ◽  
Perifusion System

Abstract. The effect of pretreatment in vivo with oestradiol benzoate on in vitro secretion of LH and FSH was studied in long-term ovariectomized (OVX) rats both at the end of a 5-day continuous in vivo pretreatment with LRH and 4-days after cessation of such LRH pretreatment. Rats were on day 0 sc implanted with osmotic minipumps which released LRH at the rate of 250 ng/h. Control rats were implanted with a piece of silicone elastomer with the dimensions of a minipump. On days 2 and 4 the rats were injected with either 3 μg EB or with oil. On day 5 part of the rats were decapitated and the in vitro autonomous (i.e. non-LRH-stimulated) and 'supra-maximally' LRHstimulated release of LH and FSH was studied using a perifusion system. From other rats the minipumps were removed on day 5 and perifusion was performed on day 9. On the 5th day of the in vivo LRH pretreatment the pituitary LH/FSH stores were partially depleted; the pituitaries of the EB-treated rats more so than those of the oil-injected rats. EB alone had no significant effect on the content of the pituitary LH- and FSH stores. On day 9, i.e. 4 days after removal of the minipumps, the pituitary LH and FSH contents had increased in both the oil- and the EB injected rats, but had not yet recovered to control values. In rats not subjected to the 5-days pretreatment with LRH EB had a positive effect on the supra-maximally LRH-stimulated secretion of LH and FSH as well as on the non-stimulated secretion of LH. EB had no effect on the non-stimulated secretion of FSH. After 5 days of in vivo pretreatment with LRH only, the in vitro non-stimulated and supra-maximally LRH-stimulated secretion of both LH and FSH were strongly impaired, the effect correlating well with the LRH-induced depletion of the pituitary LH/FSH stores. In such LRH-pretreated rats EB had on day 5 a negative effect on the (already depressed) LRH-stimulated secretion of LH (not on that of FSH). EB had no effect on the non-stimulated LH/FSH secretion. It could be demonstrated that the negative effect of the combined LRH/EB pretreatment was mainly due to the depressing effect of this treatment on the pituitary LH and FSH stores: the effect of oestradiol on the pituitary LRH-responsiveness (release as related to pituitary gonadotrophin content) remained positive. In LRH-pretreated rats, however, this positive effect of EB was smaller than in rats not pretreated with LRH. Four days after removal of the minipumps there was again a positive effect of EB on the LRH-stimulated secretion of LH and FSH as well as on the non-stimulated secretion of LH. The positive effect of EB on the pituitary LRH-responsiveness was as strong as in rats which had not been exposed to exogenous LRH. The non-stimulated secretion of FSH was again not affected by EB. The results demonstrate that the effect of EB on the oestrogen-sensitive components of gonadotrophin secretion consists of two components: an effect on the pituitary LRH-responsiveness proper, and an effect on the pituitary LH/FSH stores. The magnitude of the effect of EB on the LRH-responsiveness is LRH dependent: it is very weak (almost zero) in LRH-pretreated rats, but strong in rats not exposed to LRH as well as in rats of which the LRH-pretreatment was stopped 4 days previously. Similarly, the effect of EB on the pituitary LH and FSH stores is LRH-dependent: in the absence of LRH, EB has no influence on the contents of these stores, but EB can potentiate the depleting effect of LRH on the LH/FSH-stores. Also this effect disappear after cessation of the LRH-pretreatment.

Insulin and glucagon secretion from rat islets maintained in a tissue culture-perifusion system

Diabetes ◽  
1979 ◽  
Vol 28 (4) ◽  
pp. 276-281 ◽  
Author(s):  
R. L. Gingerich ◽  
S. L. Aronoff ◽  
D. M. Kipnis ◽  
P. E. Lacy
Keyword(s):  
Tissue Culture ◽  
Glucagon Secretion ◽  
Rat Islets ◽  
Insulin And Glucagon Secretion ◽  
Perifusion System

Perifusion system for isolated cells

1981 ◽  
Vol 112 (1) ◽  
pp. 117-127 ◽  
Author(s):  
Rapier H. McMenamy ◽  
Jochen Kleineke ◽  
Walter Roil ◽  
Hans-Dieter Söling
Keyword(s):  
Isolated Cells ◽  
Perifusion System

Extracellular calcium and adrenergic and cholinergic effects on islet beta-cell function

1976 ◽  
Vol 231 (4) ◽  
pp. 1246-1249 ◽  
Author(s):  
IM Burr ◽  
AE Slonim ◽  
V Burke ◽  
T Fletcher
Keyword(s):  
Insulin Release ◽  
Calcium Concentration ◽  
Direct Evidence ◽  
Cell Function ◽  
Insulin Response ◽  
Calcium Content ◽  
Biphasic Insulin Release ◽  
Perifusion System ◽  
Cholinergic Effects

An in vitro perifusion system utilizing collagen-medium calcium on the dynamics of insulin release as induced by acetylcholine (ACh) stimulation (in the presence of glucose, 2.4 mM) and as modified by prior perfusion of islets in epinephrine. Continuous challenge with ACh produces a biphasic insulin release response, both phases of which are reduced when the medium calcium concentration is reduced during stimulation; when the calcium content is reduced during an initial perifusion period of 30 min and then replaced during subsequent stimulation only the first phase of the response to ACh is affected; perifusion with epinephrine prior to stimulation with ACh produces enhancement of both phases of ACh-induced insulin release when calcium in both media is normal. However,.when this experiment is repeated utilizing a medium with low calcium content during the period of exposure to epinephrine the priming effect of epinephrine on the subsequent insulin response to ACh is abolished (in fact, reversed). These studies provide direct evidence for a role for calcium in mediating an effect of epinephrine on insulin release. Further, the data suggest that epinephrine affects Ca transport in islets in some manner beyond stimulating net efflux from islets, perhaps by enhancing membrane binding of calcium.

Somatostatin inhibits VIP-stimulated amylase release from perifused guinea pig pancreatic acini

1988 ◽  
Vol 254 (2) ◽  
pp. G217-G223 ◽  
Author(s):  
P. Singh ◽  
I. Asada ◽  
A. Owlia ◽  
T. J. Collins ◽  
J. C. Thompson
Keyword(s):  
Guinea Pig ◽  
Fold Increase ◽  
Optimal Conditions ◽  
Amylase Release ◽  
Pancreatic Acini ◽  
In Vitro System ◽  
Basal Release ◽  
Perifusion System ◽  
Chamber Size

We have examined the direct effect of somatostatin (SRIF) on basal and stimulated amylase release from guinea pig pancreatic acini using the in vitro method of continuous perifusion. The optimal conditions of flow rate, chamber size, acinar cell volume per chamber, and period of secretagogue infusion were defined for the perifusion system. The kinetic profile of amylase release in response to cholecystokinin-octapeptide (CCK-8), vasoactive intestinal peptide (VIP), and SRIF was studied. Under optimal conditions, the acini were found to remain equally responsive to an ED50 dose of CCK-8 (0.5-0.8 nM) for 12 h of perifusion. The duration of amylase response to any given dose of CCK-8, given for the optimal period of 5 min, was 80-100 min. The total amylase released minus the basal release divided by 90 min (delta response) in response to the maximum effective (Maxeff) dose of CCK-8 (100 nM) was 14,667 +/- 1,433 U/l (amounting to a 10-fold increase compared with basal values). When compared with the amount of total delta amylase released in response to the Maxeff dose of CCK, the total amylase released in response to the Maxeff doses of SRIF (1 microM) and VIP (10 nM) was 10-21% and 51-59%, respectively. SRIF (100 nM) significantly decreased VIP- (0.1-1.0 nM) stimulated amylase release by 45-70% in the perifusion method of study but had no significant effect on the CCK-stimulated amylase release. This suggests that the perifusion method can be used for investigating the mechanism of SRIF-mediated inhibition of VIP effects on amylase release in an in vitro system.

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