Gilst, W.H. van

Robillard, G.T.

Wildevuur, Ch.R.N.

English

Dissertations of the University of Groningen

   University of GroningenCardioprotection with the Ca-Entry Blocker, Diltiazem. Monitoring of Energy Metabolism with31P-NMR and Assay of Myocardial Loss of Nucleosides.Gilst, W.H. van; Robillard, G.T.; Wildevuur, Ch.R.N.IMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite fromit. Please check the document version below.Document VersionPublisher's PDF, also known as Version of recordPublication date:1985Link to publication in University of Groningen/UMCG research databaseCitation for published version (APA):Gilst, W. H. V., Robillard, G. T., & Wildevuur, C. R. N. (1985). Cardioprotection with the Ca-Entry Blocker,Diltiazem. Monitoring of Energy Metabolism with 31P-NMR and Assay of Myocardial Loss of Nucleosides..CopyrightOther than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of theauthor(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).The publication may also be distributed here under the terms of Article 25fa of the Dutch Copyright Act, indicated by the “Taverne” license.More information can be found on the University of Groningen website: https://www.rug.nl/library/open-access/self-archiving-pure/taverne-amendment.Take-down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediatelyand investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons thenumber of authors shown on this cover page is limited to 10 maximum.Download date: 12-10-2022234 Vol .  7 - I985 Pharrnaceutisch Weekblad Scientific Edition ASCORBIC ACID: ITS CELLULAR TRANSPORT CHARACTERISTICS Maikel Rashoebar,Jan A;M.Huisman and Cees A.M. van Ginneken The cellular pharmacokinetics of L-ascorbic acid (AA) is especially relevant in view of the direct effects of this vitamin on cell, notably leucocyte, function. ~le silicone oil cushion method that we used previously to determine the cell association of salicylic acid (]) also appears to be suitable for quantitative determination of the cellular association of (14C)-AA and its oxidized form (14C)dehydro- ascorbic acid (DHA). As these compounds are labile in aqueous solutions, it was necessary to perform all experi- ments according to very strict protocols. Further concurrently with all radiochemical experiments spectra- photometric observations were done in order to establish the enzymatic and no'nenzymatic oxidation rate of AA and the intactness of the cells. 'Hie degree of cell association of AA (extraeellular concentration range of IO to I40 u:l) turned out to be I-3 % to polymornhonuclear leucocytes (PMNs), O.4-1.2 7. to mononuclear leucocytes and 0-0.2 Z to erythrocytes, pHN accumulation of DNA (3-4 Z) exceeded that of AA considerably. The percentual association of A2X to PMNs was dependent on extracellular concentration of AA (with an apparent K d of about 44 uH). incubationo tempera-. t o r e  ( a s s o c i a t i o n  beinR lower  a t  4 than a t  37 C),  i n t a c t -  ness  of  the c e l l s  ( l y s i s  caused  50 to 80 7 d e c r e a s e )  and the e x t r a c e l l u l a r  pH (optimum a t  pH 6 l .  We s u g g e s t  t h a t  the a ' s s o c i a t l o n  p r o c e s s  c o m p r i s e s  a t  l e a s t  one s a t u r a b l e  p a t h -  way. 111is i s  c o r r o b o r a t e d  by the s i g n i f i c a n t  i n h i b i t i o n  of t o t a l  c e l l u l a r  a s s o c i a t i o n  by p r o b e n e e i d .  I n t e r e s t i n g l y ,  we found t h a t  a c t i v a t i o n  of  PMNs by the tumor promotor  phorbol  m y r i s t a t e  a c e t a t e  e x a g g e r a t e s  the a c c u m u l a t i o n  of  AA t h r e e f o l d .  The d e m o n s t r a t i o n  of  a s u b s t a n t i a l  a s s o c i a t i o n  of  AA to PblNs i s  e s p e c i a l l y  r e l e v a n t  in view of  tile f a c t  t h a t  i t  i s  g e n e r a l l y  a c c e p t e d  t h a t  ma in ly  DHA is  taken up hv PMNs. I. H. Raghoebar  e t  a l .  Biochem. Pharmaco l .  33 (1984)  2t~37. Depar tment  of Pharmaco logy ,  U n i v e r s i t y  of Nijmt~gt, n,  P.O. Box 9101 ,  8500 HB Ni jmegen,  The N e t h e r l a n d s .  ISOLATION AND ORGANIC ANION TRANSPORT PROPERTIES OF MEMBRANE VESICLES FROM DOG RENAL CORTEX F.C..M. R u s s e l ,  P,E.M. van de r  L inden ,  W.G. Vermeulen and C.A.M. van Ginneken isolated membrane vesicles have become a powerful tool in the study of renal transport mechanisms. In order to support our in vivo investigations on the renal handling of arylcarboxylic acids and their conjugates we developed an isolation procedure for brush border (BBMV) and baso- lateral membrane vesicles (BLMV) from dog kidney. BBMV and BLMV were i s o l a t e d  s i m u l t a n e o u s l y  from p r o x i ~  mal t u b u l a r  c e l l s  of  the  r e n a l  c o r t e x .  BBMV were  p r e p a r e d  by a C a C t i - p r e c i p i t a t i o n  method and membrane s u s p e n s i o n s  e n r i c h e d  For BLMV were i s o l a t e d  w i t h  a s e l f - o r i e n t i n g  P c r c o l l  g r a d i e n t .  The enzyme m a r k e r s  f o r  BBbIV, a l k a l i n e  p h o s p h a t a s e ,  and f o r  BLMV, Na-K-ATPase,  were e n r i c h e d  from the  c rude  homogenate 10- to 1 2 - f o l d  and 8 -  to I O - f o l d  r e s -  p e c t i v e l y .  Only l i t t l e  c r o s s  c o n t a m i n a t i o n  was o b s e r v e d .  The u p t a k e  of U - i ~ H ] g l u c o s e  and p - a m i n o / 3 H J h i p p u r a t e  (PAtt) ill  t h e s e  v e s i c l e s  was s t u d i e d  by a r a p i d  f i l t r a t i o n  t e c h n i q u e .  BLMV were f r e e  of  D - g l u c o s e  t r a n s p o r t  and showed a s a t u r a b l e  sodium coup l ed  P~hq up t ake  s e n s i t i v e  to p r o b e n e c i d .  A r a p i d  sodium dependen t  O - g l u c o s e  u p t a k e  was . b s e r v e d  in BB,MV. PAH u p t a k e  in t h e s e  v e s i c l e s  c o u l d  be s t i m u l a t e d  both  by a sodium g r a d i e n t  and an i n w a r d l y  d i -  rt, c l o d  t t * - g r a d i e n t .  I n t e r e s t i n g l y ,  pH s t i m u l a t e d  t r a n s p o r t  was more s e n s i t i v e  to  p r o b e n e c i d  and showed h i g h e r  i n i t i a l  , lp takc  r a t e s .  I s o l a t e d  membranes cou ld  be s t o r e d  f o r  s e v e r a l  weeks a t  -80"  C w i t h o u t  l o s s  of  .D-g lucose  and PAH t r , m s p o r t  a c t i v i t y .  However,  d e s p i t e  the f i n d i n g s  of  s e v e -  r a l  m J t h u r s ,  v e s i c l e s  i s o l a t e d  from f r o z e n  c o r t e x  showed poor t r~ll lsport  p r o p e r t  i t s .  I'he s u h s t r a t e  s p e c i f i c i t y  of  the  PAll t r a n s p o r t e r  in  IJt;>lk' and BI.,'-IV is  c u r r e n t l y  s t u d i e d  by c o m p e t i t i o n  e x p e r i -  :a,.nts ~ ' i th  a s e r i e s  of  s . b s t i t u t e d  a r y l c a r b o x y l i c  a c i d s  .rod t M : i r  ~ l y c i n c  c o n , i , g a t u s .  ]Mp,~rtl,t,nt of  Pharn laco logy ,  U n i v e r s i t y  of Ni jmegen ,  i'.L~, t,t.:.: -~1OI. t~5{IO lib Niimt.gen,  The N e t h e r l a n d s  CARDIOPROTECTION WITH THE Ca-ENTRY BLOCKER.DILTIAZEN. MONITORING OF ENERGY METABOLISM WITH 31P-N~ AND ASSAY OF MYOCARDIAL LOSS OF NUCLEOSIDES. F.D. Rahusen, W.H. van Gilst, G.T. Robillard, Ch.R.N. Wildevuur. ...................................................... Earlier studies have shown improved 24 hrs hypothermic cardiac preservation with diltiazem by protection during reperfusion. This was shown by reduced overflow of adenosine during reperfusion, Total purine overflow in the first minute of reperfusion was comparable to control hearts. Therefore, it is uncertain whether diltiezem exerts any effect during Ischemia. In this study nuclear magnetic resonance was used to quantitate high energy phosphates and intracellular pH in order to investigate the processes during ischemia. Isolated rat hearts were maintained in hypothermic ischemia for 6 hrs after a perfusion according to Langendorff. NMR measurements were done at 1 hr intervals. Subsequently hearts were reperfused and the coronary effluent was collected for assay of nucleosides. Diltiazem (30 uM) treatment was started 15 minutes before ischemia In=6). Six hearts served as controls. The results showed no significant differences in NF~ measurements; in both groups pll was lowered to 6.01 • O.10 for control and 6.08 ~ 0.07 for treated hearts and ATP had disappeared after 4 hrs. In relation to these findngs there were also no significant differences in total purine overflow during the first minute of reperfusion (1529 ~ 144 nH/min.gdwt for control group and 1570 • 193 nM/min.gdwt for treated group). Control hearts showed delayed adenosine overflow due to reperfusion induced damage (max. overflow 25 ~ I0 nM/min.gdwt). This was abolished by diltiazem treatment. It is concluded that: I) NMR is a very useful tool to monitor high energy phosphates and correlates well with the total purine overflow in the coronary effluent. 2) diltiazem is indeed effective only during reperfuaion. Depts of Clinical Pharmacology/Experimental Surgery/Physical Chemistry, Bloemsingel I, 9713 BZ Oroningen, The Netherlands. ARE CATECHOLAMINERGIC AND SEROTONERGIC NEURONS INVOLVED IN UPTAKE AND RELEASE OF HISTAMINE BY RAT BRAIN SLICES? R.P.J.M. Smits, H.II.M. Steinhusch and A.H. Mulder. Substant ia l  evidence supports the view that  h istamine (HA) functions as a neurotransmltter in the CNS. Analogous to other monoaminergic neuronal systems a specific high affini- ty (re-)uptake mechanism for HA into histaminerglc neurons might be expected to exist, but direct evidence for this is lacking. Nevertheless, we have shown previously, that 3H-HA is taken up by brain sllces and can subsequently be released by depolarizing stimuli. However, although it was demonstra- ted that 3H-HA release originates from neurons, it still re- mains uncertain, whether or not exclusively histaminergic neuron'~ are involved. Therefore, uptake and/or release of 3H-HA as well as that of 3H-noradrena]ine (NAJ, 3H-SliT and 3H-dopamine (DA) by slices from different rat brain regions ..acre stcdied after various pharmacological treatments. Pre- treatment wi th 6-hyd'roxydopamine {6-OH-DA), destroying ca- techolarninergic nerve terminals, lowered 3H-NA uptake (hip- pocampus) by 90% whereas 3H-HA uptake remained unchanged. On the other hand, 6-OH-DA lesions resulted in a decreased uptake of~oth 3H-DA (-85%) and 3H-HA (-40%) by striatal s ] ices. S~ili lar ly, pretreatment with 5,7-dlhydroxytryptamine (5,7-DHT), destroying serotonergic nerve terminals, reduced the uptake of both 3H-SHT (-70%) and 3H-HA (-40%l by hippo- campal ~lices. Immunocytochemlcal data indicated that hlsta- minergic neurons were not affected by either 6-OH-DA or 5,7- DHT. The data suggest that, whereas uptake of 3H-HA into noradrenergic neurons seems unl ikely, dopaminergic and sero- tonergic neurons may contribute to a significant extent to the uptake of 3H-HA in brain slices. This conclusion is fur- ther supported by the results of experiments examining whe- ther the electrically evoked release of 3H-HA, like that of 3H-NA (cortex), 3H-DA (striatum) and 3H-SHT (hippocampusl, is subject to presynaptic modulation by activation of NA-, DA-, 5HT- or opioid receptors. Dept. of Pharmacology, Free University Medical Faculty, Van der Boechorststraat 7, 1081 BT Amsterdam. 

Cardioprotection with the Ca-Entry Blocker, Diltiazem. Monitoring of Energy Metabolism with 31P-NMR and Assay of Myocardial Loss of Nucleosides.

https://pure.rug.nl/ws/files/98233383/1985PharmacWeekSciEdRahusen.pdf

Cardioprotection with the Ca-Entry Blocker, Diltiazem. Monitoring of Energy Metabolism with 31P-NMR and Assay of Myocardial Loss of Nucleosides.

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