Case Study : iPRECIO- 5HT ᢞ୚

The Gold Standard in Chronic Physiologic Monitoring

iPRECIO兂儈儓兑儈兗儹光兠儜克兗允兗儻僸⏝傪僅傎僮僰ᑡ僐傪⏝㔞働僔䢷䢯䣊䣖䢪償兑儬儯兗䢫ᢞ୚僑僮僱⾑ᅽ㝆ୗస⏝僔ⓎぢMichigan State University, East Lansing MIRobert Patrick Davis, Gregory D. Fink, Bridget Seitz, Stephanie Watts
せ⣙ /Summary៏ᛶⓗ僐償兑儬儯兗凚5-儶儭兑儑儛儬兎儻儣元兗; 5-HT凛ὀධ僕傎ᣢ⥆ⓗᮏ◊✲僕傎5-HT㏦㐩⋡僔ቑຍ傲傎SD(Sprague Dawley)免儧儬僔僐⾑ᅽ凚BP凛僔పୗ僸ᘬ傳㉳傹傽僤傿傏 傹僔◊✲ᐊ働僕௨๓僑傎SD(Sprague Dawley)免儧儬働7᪥㛫傎ᾐ㏱ᅽ允兗儻僸⤒僌ᢞ୚傻僲僱㐃⥆⓶ୗὀධἲ僸⏝傪傎5-HT僔㝆ᅽస⏝僸᳨ウ傽僌傪僤傿傏ᡃ傑僕傎5-HT僔ᢞ୚㔞ቑຍ傲傎⾑ᅽ僔傎僮僰኱傳僐ῶᑡ僑ᖐ╔傿僱僎௬ᐃ傽僤傽僅傏5-HT僤僅僕㈿ᙧ๣凚Vehicle凛僸傎᭱ึ傎୍ᐃ僔㏿ᗘ働48᫬㛫傎iPRECIO允兗儻僸௓傽僌⓶ୗὀධ(s.c. : subcutaneousinjection)ᢞ୚傽傎僃僔ᚋ傎48᫬㛫ᢞ୚僸೵Ṇ傽僅ᚋ傎᭱⤊ⓗ僑
45mg/kg/ศ僤働ẁ㝵ⓗ僑㧗僧僅儭兠儞㔞僸ᢞ୚傽僤傽僅傏ᖹᆒື⬦ᅽ僕傎DSI免儜儎優児充儬兎兠働兆儯儣兠傽僤傽僅傏ᮏᐇ㦂働僕傎௨๓᥇⏝傽僅僮僰僨僮僰ᑡ僐傪5-HT凚償兑儬儯兗凛ᢞ୚㔞働傎䣕D(Sprague Dawley)免儧儬僑傰傷僱㝆ᅽຠᯝ傲ㄏⓎ傻僲僱傹僎傲ド᫂傻僲僤傽僅傏᭦僐僱ᐇ㦂傲㐍⾜୰働傿傏⾑ᅽ僸傎ẁ㝵ⓗ僑僮僰ῶᑡ傻僁僱⤖ᯝ僑ᖐ╔傿僱傱像催傱僑僊傪僌ㄪᰝ傽僮催僎ヨ僥僤傽僅傏ᗎㄽ /Introduction償兑儬儯兗凚5-儶儭兑儑儛儬兎儻儣元兗傎5-HT凛僕傎ᾘ໬⟶僔⭠儓兑兄ぶ࿴ᛶ⣽⬊僎୰ᯡ⚄⤒⣔僔⦭⥺᰾僑僮僉僌୺僑ྜᡂ傻僲僱⾑⟶స⏝ᛶ儆元兗働傿傏5-HT(償兑儬儯兗)僕傎⾑⟶ᖹ⁥➽僔ᙉຊ僐཰⦰⸆僎ゝ僵僲傎⬟ືⓗ僑償兑儬儯兗㍺㏦య凚SERT凛僑僮僉僌ཷ傷ධ僲僯僲傎⣽⬊ෆ僔兆儲儆元兗㓟໬㓝⣲凚MAO:monoamine oxidase凛僑僮僉僌傎୙άᛶ௦ㅰ⏘≀凚5-儶儭兑儑儛儈兗儭兠兏㓑㓟凚5-HIAA凛凛僞僎傎ᛴ㏿僑௦ㅰ傻僲僤傿傏償兑儬儯兗㍺㏦య(SERT)僕傎⾑ᑠᯈ傎ෆ⓶⣽⬊僎ᖹ⁥➽⣽⬊僑Ꮡᅾ傽僤傿傏(1)ᮦᩱ僎᪉ἲ /Materials and Methods[優児充儬兎兠]儈儡儹兏免兗㯞㓉ୗ働傎㞝僔SD(Sprague Dawley)免儧儬ᕥ㰢ᚄ㒊㡿ᇦ僔1-1.5cm僔ษ㛤僸㏻傾僌傎免儜儎兟優児充儬兎兠兟儫儴儈儝凚DataSciences International, St. Paul, MN凛僸⓶ୗ僑ᇙ㎸僥僤傽僅傏
優児充儬兎兠兟儫儴儈儝僔儏優兠優兏僸傎⭡⭷ቨ傱僯3-5mm㐲఩僔ᕥ኱⭣ື⬦僮僰ᑟධ傽傎ඛ➃僔償兗儙兠㒊僸⭡㒊኱ື⬦僞㐍僧僤傽僅傏免儧儬僕傎ᡭ⾡ᚋ3-4᪥僔ᅇ᚟ᮇ㛫僸⤒僌傎3-4᪥僔儽兠儝免儈兗 ᐃ僸⾜傪僤傽僅傏䢢ᐇ㦂ᮇ㛫඲య僸㏻傾僌傎ᖹᆒື⬦ᅽ
凚MAP凛僎ᚰᢿᩘ凚HR凛僸グ㘓傽僤傽僅傏免儧儬僕傎⭡⭍ෆ儾兗儬儴兏儷儣兠兏儮儬兎儊兄凚60mg/kg凛僸౑⏝傽僌ᏳᴦṚ傻僁傎ᚰ⮚✸่僑僮僉僌඲⾑僸཰㞟傽僤傽僅傏䢢⬚㒊኱ື⬦傎㢕ື⬦傎㢕㟼⬦僎⬚㒊኱㟼⬦僸傎ᇶ♏ⓗ僐5-HT ᐃ僔僅僧僑ྲྀ僰ฟ傽僤傽僅傏[iPRECIO兂儈儓兑儈兗儹光兠儜克兗允兗儻]㢮ఝ傽僅㯞㓉᪉ᘧ僸౑⏝傽僅➨2僔ᡭ⾡୰僑傎iPRECIO允兗儻凚Primetech傎Tokyo Japan凛僸傎㢕㒊僔ᇶᗏ僑సᡂ傽僅ᑠ傻僐ษ㛤
僸㏻傽僌ᇙ㎸僥僤傽僅傏 㕌ⓗ๤㞳僸⏝傪傎⫪⏥㦵僔㛫僑ᑠ傻僐⓶ୗ允儕儧儬僸సᡂ凚ᅗ3凛傽僤傽僅傏 允兗儻僸ᤄධ傽傎ษ㛤傽僅⓶⭵僸㛢傾僌⦭ྜ傽僤傽僅傏ᅇ᚟ᚋ傎5-HT僤僅僕㈿ᙧ๣僸傎ྛ允兗儻僑兑兠儭傽僤
傽僅傏5-HT⁐ᾮ僕傎percreatinine complex僎1%儆儝儗兏儷兗㓟凚ᢠ㓟໬๣凚0.02g/允兗儻凛凛僸⏝傪傎ྛ᫬Ⅼ働஧僊僔᪉ἲ㧗⾑ᅽ僎5-HT凚償兑儬儯兗凛僔㛵ಀ僸♧၀傿僱◊✲⤖ᯝ傲储僰僤傿傏傹僲僯僔◊✲働僕傎ṇᖖ⾑ᅽ僔儶儬兟ື≀儗兗儬兑兠兏僎ẚ㍑傽傎
㧗⾑ᅽ僔儶儬兟ື≀୧兆儫兏僑傰傪僌傎⾑₢㐟㞳5-HT僔ୖ᪼傲♧၀- ANOVAศᯒ僎஦ᚋ᳨ᐃ僑僮僉僌ホ౯傽僤傽僅傏 ⁐ᾮ僕1N HCl
傻僲(2-3)傎5-HTཷᐜయᣕᢠ๣傲傎㑅ᢥ傻僲僅㧗⾑ᅽ兆儫兏ື≀僑働⁐傱傽傎pH儴免兗儝凚~7凛僸4N NaOH働ㄪᩚ傽僤傽僅傏傰傪僌⾑ᅽ僸㝆ୗ傻僁僱傹僎僸♧၀傽僌傪僤傿(4).
㧗⾑ᅽື≀僔ື⬦僕5-HT僔཰⦰๣స⏝僑␗ᖖ僑ᙉ傪཯ᛂ僸♧傽傎僃傽僌傎㑅ᢥⓗ僐5-HT෌ྲྀ㎸僥ᢚไᅉᏊ僕⾑ᅽ僸ୖ᪼傻僁僤傿凚5-7凛傏傹僔ドᣐ僑僨傱傱僵僯僀傎᭱㏆僔▱ぢ働僕傎5-HT僑僕傎㞝僔㓑㓟儫儎儑儛儗兏儥儗儝優兑兗凚DOCA凛-ሷ㧗⾑ᅽᛶ僎ṇᖖ⾑ᅽᛶ凚Sham凛僔免儧儬僑傰傪僌傎⾑ᅽ僸ୗ傸僱㦫債僟傳⬟ຊ傲储僱傹僎僸ド᫂傽僌傪僤傿傏(8)ᅗ3Case Study : iPRECIO- 5HT ᢞ୚

The Gold Standard in Chronic Physiologic Monitoring⤖ᯝ傍/Results
iPRECIO兂儈儓兑兟儈兗儹光兠儜克兗允兗儻僕傎ᡃ傑僔◊✲ᐊ僑傎5-HT僔ቑຍ傻僁僅ᢞ୚㔞僸傎༢୍兟ぬ㓰ୗ兟⮬⏤άືୗື≀僑ᢞ୚傿僱స⏝僸ㄪᰝ傿僱僅僧僔㠉᪂ⓗ僐儨兠兏僸ᥦ౪傽僤傽僅傏ᡃ傑僕傎௨๓僔⏝㔞僎ẚ㍑傽傎SD(Sprague Dawley)免儧儬僑ᑐ傿僱

ᅗ1凬㓑㓟儫儎儑儛儗兏儥儗儝優兑兗凚凶刁凵凳凛-ሷ㧗⾑ᅽᛶ免儧儬凚3n凬㉥⥺䢫僎儛兇兄ṇᖖ⾑ᅽᛶ免儧儬凚5n:㯮⥺凛僑傰傷僱傎៏ᛶⓗ僐5-HTᢞ୚僔ᚰᢿᩘ凚HR凛僞僔ᙳ㡪䢢C=control、S=infusion

5-HT僔ቑຍ傻僁僅⏝㔞僸ᢞ୚傿僱傹僎僑僮僰傎⾑ᅽ僕傎ḟ➨僑僮僰኱傳債ῶᑡ傿僱⤖ᯝ僑ᖐ╔傿僱傹僎僸௬ᐃ傽僤傽僅傏傹僔ᐇ㦂働僕傎ቑຍ傻僁僅5-HT傲⾑ᅽ僸ḟ➨僑㝆ୗ傻僁僱傹僎僕僐債傎
SD(Sprague Dawley)免儧儬僑傰傪僌㝆ᅽస⏝僸ㄏⓎ傿僱僑僕傎僮僰ᑡ僐傪⏝㔞僔5-HT働僮傪傹僎傲ド᫂傻僲僤傽僅傏凚ᅗ1・2凛傹僲僯僔▱ぢ傱僯傎ᑗ᮶僔ᐇ㦂働僕傎僮僰ᑡ僐傪⏝㔞働僮傪傹僎傎≉僑≉ᐃ僔5-HTస⏝⸆(儆儘儯儝儬)僑↔Ⅼ僸ᐃ僧僅ᐇ㦂僑僎僉僌ព࿡傲储僱傹僎傲♧၀傻僲僤傿傏ウㄽ傍/Discussion傹僔◊✲ᐊ僕傎5-HT僑ᑐ傿僱⏝㔞཯ᛂ僔௦僵僰僑傎ྠ傾౯್僔ຠᯝ僸傎௨๓⾜僉僅᫬僮僰僨傎僮僰ᑡ僐傪⏝㔞働ᡂ傽㐙傸僱傹僎傲ྍ⬟働储僱傹僎僸Ⓨぢ傽僤傽僅傏䢢傹僔Ⓨぢ僕傎⮬⏤άືୗ兆儫兏僑傰傪僌僕傎᪤Ꮡ僔ᢏ⾡働僕୙ྍ⬟働傽僅傏
iPRECIO僕傎᪤Ꮡ僔儈兗儹光兠儜克兗᪉ἲ傱僯僔ᢏ⾡ⓗ僐㐍Ṍ働储僱傹僎傲ド᫂傻僲僅僎ඹ僑傎傹僔◊✲ᐊ傲傎⏕⌮Ꮫⓗ僐᳨⣴⬟ຊ僎ື≀⚟♴僸ྥୖ傻僁僱୍᪉働傎໬ྜ≀兟ປാ兟⤒㈝僸⠇⣙傻僁僱ពᛮỴᐃ僸๓㐍傻僁僱傹僎僸ྍ⬟僑傽僤傽僅傏 傹僔◊✲ᐊ僕iPRECIO允兗儻僔ᛶ⬟僑‶㊊傽僌傎᭦僐僱ᐇ㦂働傹僔〇ရ僸౑⏝傿僱ィ⏬働傿傏ᅗ2凬㓑㓟儫儎儑儛儗兏儥儗儝優兑兗凚凶刁凵凳凛-ሷ㧗⾑ᅽᛶ免儧儬凚3n凬㉥⥺䢫僎儛兇兄ṇᖖ⾑ᅽᛶ免儧儬凚5n:㯮⥺凛僑傰傷僱傎៏ᛶⓗ僐5-HTᢞ୚僔ᖹᆒ⾑ᅽ凚MAP凛僞僔ᙳ㡪䢢C=control、S=infusion

1. Ni, W. et al. The Serotonin Transporter is Present and Functional in Peripheral Arterial Smooth Muscle. Journal of Cardiovascular Pharmacology. 2004. 43: 770-781.
2. B. Brenner, J.T. Harney, B.A. Ahmed, B.C. Jeffus, R. Unal, J.L. Mehta, and F. Kilic. Plasma serotonin levels and the platelet serotonin transporter. J Neurochem.
(2007) 102: 206-215.
3. Carrasco G, Cruz MA, Gallardo V, Miguel P, Lagos M, and Gonzalez C (1998) Plasma and platelet concentration and platelet uptake of serotonin in normotensive andpreeclamptic pregnan cies. Life Sci 62: 1323-1332.
4. Brenner B, Harney JT, Ahmed BA, Jeffus BC, Unal R, Mehta JL, Kilic F (2007) Plasma serotonin levels and the platelet serotonin transporter. J Neurochem 102: 206-215.
5. Watts SW and Fink G (1999) 5-HT2B-receptor antagonist LY-272015 is antihypertensive in DOCA-salt-hypertensive rats. Am J Physiol Heart Circ Physiol 276: 944-952.
6. Watts SW (2005) 5-HT in systemic hypertension; foe, friend or fantasy? Clin Sci 108: 399-412.
7. Amsterdam JD, Garcia-Espana F, Fawcett J, Quitkin FM, Reimherr FW, Rosenbaum JF, and Beasley C (1999) Blood pressure changes during short-term fluoxetinetreatment. J Clin Psycho pharm 19: 9-14.
8. Diaz, J. Ni, W. Thompson, J, King A, Fink G, Watts SW. (2008) 5-hydroxytryptamine lowers blood pressure in normotensive and hypertensive rats. JPET. 325: 1031-1038‫࠾ە‬ၥྜࡏඛ(iPRECIO⥲Ⓨ኎ඖ࣭DataSciences♫᪥ᮏ⥲௦⌮ᗑ)㸸

ᮾி㒔ᩥி༊ᑠ▼ᕝ 1-3-25 ᑠ▼ᕝ኱ᅜࣅࣝ9F(ᮾி)Phone:03-3816-0851 (኱㜰)06-6310-8077
www.primetech.co.jp
infusion@primetech.co.jp

2012.07 (rev01)

iPRECIO®– 5-HT Administration

Case Study

Michigan State University, East Lansing MIRobert Patrick Davis, Gregory D. Fink, Bridget Seitz, Stephanie Watts
Summary: Chronic serotonin (5-hydroxytryptamine; 5-HT)
infusion causes a prolonged fall in blood pressure (BP). Thislab previously studied the hypotensive effects of 5-HT using acontinuous subcutaneous infusion administered via osmotic
pump for 7 days in the Sprague Dawley rat (S.D.). We hypothesized that increasing delivery rates of 5-HT would resultin greater reductions in BP. 5-HT or Vehicle (Veh) was administered s.c. via the iPrecio® micro infusion pump for 48 hrs at
an initial constant rate, stopped for 48 hrs and then deliveredin escalated dosages to a final rate of 45mg/kg/min. Mean arterial BP was monitored with DSI radiotelemetry. This study
demonstrated that a smaller rate of 5-HT than previously employed elicits a hypotensive effect in the S.D. rats. Further
study is ongoing.

Introduction
Serotonin (5-hydroxytryptamine, 5-HT) is a vasoactive aminesynthesized mainly by enterochromaffin cells of the gastrointestinal tract and raphe nucleus in the CNS. Initially described
as a potent vasoconstrictor of smooth muscle, 5-HT is actively
taken up by the serotonin transporter (SERT) and rapidly metabolized to the inactive metabolite, 5-hydroxyindole acetic
acid (5-HIAA), by intracellular monoamine oxidase (MAO).
SERT is present in platelets, endothelial cells, and smoothmuscle cells(1).
Several lines of evidence suggest an association between hypertension and 5-HT. Studies show elevated free plasma 5-HTin both human and animal models of hypertension compared
to normotensive human and animal controls(2-3) and 5-HT receptor antagonists lower blood pressure in select animal models of hypertension(4). Arteries of hypertensive animals are
hyperresponsive to the constrictor effects of 5-HT, and selective 5-HT reuptake inhibitors elevate blood pressure(5-7).
Despite this evidence, recent findings demonstrate that 5-HT
has the surprising ability to lower blood pressure in the maledeoxycorticosterone acetate (DOCA)-salt hypertensive andnormotensive (sham) rat(8). This study sought to investigate
whether increasing delivery rates of 5-HT would result in a
progressively greater reduction in blood pressure in the Sprague Dawley rat.

Materials and Methods
Telemetry:

Under isoflurane anesthesia, radiotelemetery devices(Data Sciences International, St. Paul, MN) were implanted subcutaneously through a 1-1.5 cm incision in
the left inguinal area of male Sprague Dawley rats.
Catheters were introduced into the left femoral artery 35 mm distal to the level of the peritoneal wall, and thetip was advanced to the abdominal aorta. The rats wereallowed 3-4 days to recover post-operatively, and then 3-4 days of baseline measurements were made. Meanarterial pressure (MAP) and heart rate (HR) were recorded throughout the duration of the study. Rats wereeuthanized using intraperitoneal sodium pentobarbital(60 mg/kg), and whole blood collected via cardiac puncture. Thoracic aorta, carotid arteries, jugular veins, andFigure 1: .Effect of chronic 5-HT administration on heart rate (HR) in 3
DOCA-salt hypertensive rats (red) and 5 sham normotensive rats(black). C=control; S=infusion

iPRECIO®– 5-HT Administration

Case Studyythoracic vena cava were harvested for basal 5-HT measurements.
iPRECIO® micro infusion pump:

During a second surgery using a similar anesthetic regimen, the iPRECIO® pump (Primetech, Tokyo Japan) was
implanted through a small incision made at the base of theneck. Using blunt dissection a small subcutaneous pocket
between the scapulae was created. (Figure 3) The pump
was inserted and the skin sutured closed. Post recovery 5HT or vehicle was loaded on each pump. The 5-HT solution was assessed by a two-way mixed design ANOVA
and post-hoc testing at each time point with percreatinine
complex and 1% ascorbic acid, antioxidant (0.02 g/pump).
The solution was dissolved in 1N HCl, and a pH-balance(~7) is achieved with 4N NaOH.

Figure 3:

ResultsThe iPrecio® micro infusion pump offered our laboratory an
innovative tool to investigate the effects of delivering increasing doses of 5-HT to a single, conscious, freely moving, animal. We hypothesized that delivery of increasing
doses of 5-HT to the S.D. rat would result in progressively
greater reductions in BP when compared to the previousdose(s). This study demonstrated that increasing 5-HT did
not progressively lower BP and that a smaller dose of 5-HT
is required to elicit a hypotensive effect in the S.D. rats.
(Figure 1& 2) These findings suggest that future experiments can be conducted at a lower dose, and is particularly
relevant to studies focused on specific 5-HT agonists.

Discussion
This lab did discover that instead of a dose response to 5HT, we were able to achieve an equivalent effect at a much
lower dose then had been previously studied. This discovery would not have been possible in a fully ambulatorymodel with existing technology.

Figure 2: . Effect of chronic 5-HT administration on mean arterial pressure (MAP) in 3 DOCA-salt hypertensive rats (red) and 5 sham normotensive rats (black).

The iPRECIO® proved to be a technologic advancementfrom existing infusion methods and enabled this lab to makedecisions moving forward that will save compound, laborand money while increasing physiologic relevance and overall animal welfare. This lab is pleased with the performanceof the iPRECIO® pump and intends to use this product infurther study.

1.
2.
3.

Ni, W. et al. The Serotonin Transporter is Present and Functional in Peripheral Arterial Smooth Muscle. Journal of Cardiovascular Pharmacology. 2004. 43: 770-781.

4.
5.
6.
7.

Brenner B, Harney JT, Ahmed BA, Jeffus BC, Unal R, Mehta JL, Kilic F (2007) Plasma serotonin levels and the platelet serotonin transporter. J Neurochem 102: 206-215.

8.

Diaz, J. Ni, W. Thompson, J, King A, Fink G, Watts SW. (2008) 5-hydroxytryptamine lowers blood pressure in normotensive and hypertensive rats. JPET. 325: 1031-1038

B. Brenner, J.T. Harney, B.A. Ahmed, B.C. Jeffus, R. Unal, J.L. Mehta, and F. Kilic. Plasma serotonin levels and the platelet serotonin transporter. J Neurochem. (2007) 102: 206-215.
Carrasco G, Cruz MA, Gallardo V, Miguel P, Lagos M, and Gonzalez C (1998) Plasma and platelet concentration and platelet uptake of serotonin in normotensive and preeclamptic pregnan
cies. Life Sci 62: 1323-1332.

Watts SW and Fink G (1999) 5-HT2B-receptor antagonist LY-272015 is antihypertensive in DOCA-salt-hypertensive rats. Am J Physiol Heart Circ Physiol 276: 944-952.
Watts SW (2005) 5-HT in systemic hypertension; foe, friend or fantasy? Clin Sci 108: 399-412.
Amsterdam JD, Garcia-Espana F, Fawcett J, Quitkin FM, Reimherr FW, Rosenbaum JF, and Beasley C (1999) Blood pressure changes during short-term fluoxetine treatment. J Clin Psycho
pharm 19: 9-14.