Combining Cardiovascular, Respiratory and Neurobehavioral Endpoints for Efficient Study Design

Combining Cardiovascular, Respiratory and Neurobehavioral Endpoints for Efficient Study Design

Brian M. RochePhD, DSP, DABT

Director of Safety Pharmacology,Charles River Laboratories

Jason D. Payseur

Senior Scientist – IVIVT, MSD Safety Pharmacology USGlaxoSmithKline

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Combining plethysmography, telemetry and Allay™ restraint technology for the use in safety pharmacology and inhalation toxicology environments

Brian M. Roche PhD, DSP, DABT

Director of Safety Pharmacology,Charles River Laboratories,Ashland, OH

Copyright 2016 B.M. Roche, Data Sciences International and InsideScientific. All Rights Reserved.

Agenda

1. Allay Restraint Technology

• Overview of device

• Acclimation process

2. Allay restrainers vs. nose only cone restraint tubes

• Acclimation data

• Hemodynamic telemetry data

3. Plethysmography and Telemetry: Allay vs Head Out

• Hemodynamic assessment

• Respiratory function

• Resistance and compliance

4. Dosimetry approaches with Allay plethysmography

5. What we’ve learned from conducting this pilot study

Allay Restraint AcclimationThe Process

Allay Restraint Technology

1 Allay restraint tube

2 Neck clip

3 Plethysmography bell

4 Nose seal1

2 3

4

Important to allow for adequate time prior to study to acclimate the rats to the restraint device

Introducing the allay restraint tube and the rat either through placing the restraint tube or “sled” portion of the device into the home cage and/or manually placing and holding the rat inside the device.

Allay Restraint and Acclimation

After the initial familiarity with the device, the next step was to introduce the restraint portion of the tube.

This was conducted by manually placing and holding the rat in the device without the neck clip.

Allowing the rat to extend its head and neck out through the front of the device while it explored its surroundings.


The next step is to determine the appropriately sized “clip” for the size of the rat’s neck. This process starts as an extension of the manual restraint of the rat within the device.

Each time the rat extends it’s neck through the “clip” area, slowly place the neck clip over the rat’s neck. This step requires patience as restraining the rat too early may set you back a step in acclimation.


Once the appropriate sized neck clip is in place the rat will begin acclimating to this step of the procedure.


Once the rat has been introduced and the appropriate neck clip has been determined, acclimation to the allay restraint technology for respiratory function beings. Depending upon your study design, the next step in acclimation is to add the plethysmography bell.

This step is required if collecting respiratory function. At this point the restraint is similar to a head out chamber without a neck seal. This step is critical in the acclimation process for tail placement and temperature regulation.


Nose and mouth seal.

The nose seal can also be placed on the restraint tube without the plethysmography bell for inhalation delivery of test articles/chemicals.

The rat will react once the face whiskers are stimulated but will calm down. Additionally, the nose will be positioned directly in the center of the nose seal.


Putting it all together.

The device is functioning as a nose only plethysmography chamber for inhalation delivery. This piece is also critical for placement on the inhalation tower.

The acclimation will be conducted in steps, with increasing duration. Once the entire Allay restraint device is assembled around the rat, start building up acclimation time to cover the time that the rat will be restrained on study.


Acclimation: Allay restrainers vs. nose only restraint coneHD-S21 Telemetry – Hemodynamic data

Allay Restraint vs. Nose Only Restraint Cone

Heart rate reduced initially in Allay restrainers

No change in blood pressure between the two methods of restraint

EVERY STEP OF THE WAY16

Slight increase in body temperature, expected with no bias flow and tail enclosed in Allay restraint

Plethysmography and Telemetry: Allay vs. Head Out RestraintHemodynamic Assessment, Respiratory Function, Resistance and Compliance

Allay Restraint vs. Head Out Plethysmograph

Reduction in heart rate through first 60 minutes for Allay restraint

Allay Head Out

No change in systolic blood pressure

Allay Head Out

Slight reduction in diastolic blood pressure for initial 60 minutes in Allay restraint

Allay Head Out

Slight reduction in mean arterial blood pressure for Allay restraint

Allay Head Out

Slight reduction in body temperature for the Allay restrain

Allay Head Out

Decrease in respiratory rate for Allay restraint

Allay Head Out

Increase in tidal volume with Allay restraint

Allay Head Out

No change in minute volume

Allay Head Out

No change in lung compliance

Allay Head Out

No change in lung resistance

Allay Head Out

Dosimetry Approaches With Allay PlethysmographyInhalation drug delivery

Standard fit for the Allay restraint system with a conventional nose only inhalation system.

Inhalation tower designed with a support ring to handle the size and weight of the Allay restraint.

Allay Technology and Inhalation Tower

Telemetry hemodynamic and intrathoracic pressure data were collected in combination with respiratory function by placing a DSI RPC-1 small animal receiver in close proximity to the animal instrumented with HD-S21 transmitter.

Adequate separation of the animals throughout the inhalation tower, reduces the risk of cross-talk.

Allay Restraint and Telemetry

What we’ve learned from conducting this pilot study…

Pros… Ability to combine inhalation and dosimetry

Ability to dose via inhalation (nose only cone)

Ability to collect dosimetry (head out chamber)

Potentially less stressful (nose cone and head out)

Plethysmography - no thoracic compaction of rat vs head out

Tight seal of device when mounted on inhalation tower

Spacing collar for proper placement of head chamber and nose seal

No physical obstruction against the throat (head out chamber)

Dual chamber (reference) reduces variability of ambient pressure changes in the collection environment (head out chamber)

Cons… Nose seal

o Destruction by rat

o Ability to replace nose seal (loss of data)

Acclimation process is time consuming

Design

o Heavy (ring design of inhalation tower)

o Rolls (acclimation)

o Position of pneumotach and transducer ports (Obstructed by tail/urine/feces)

Acute Respiratory Disorders

• Respiratory Depression

• Respiratory Syncytial Virus (RSV)

• Acute Respiratory Distress Syndrome (ARDS)

• Mucociliary Clearance and Dysfunction

• Pneumonia

• Cough

• Tuberculosis (TB)

• Bronchiolitis/ Bronchitis

COPD

• Emphysema

• Chronic Bronchitis

• Model Development

• Treatment Assessment

Asthma

• Model Development

• Treatment Assessment

Lung Fibrosis

• Pulmonary Fibrosis

• Cystic Fibrosis

Safety Assessment

• Safety Pharmacology

• Toxicology

Select any of the links below to learn more about Respiratory Solutions offered by DSI.

www.datasci.com

http://www.datasci.com/solutions/respiratory/acute-respiratory-disorders

http://www.datasci.com/solutions/respiratory/copd

http://www.datasci.com/solutions/respiratory/asthma

http://www.datasci.com/solutions/respiratory/lung-fibrosis

http://www.datasci.com/solutions/respiratory/safety-assessment

Combined Cardiovascular, Respiratory, and Neurobehavioral Telemetry Model in the Conscious Rat:

Jason D. PayseurSenior Scientist – IVIVT, MSD Safety Pharmacology USGlaxoSmithKline

Copyright 2016 J.D. Payseur, Data Sciences International and InsideScientific. All Rights Reserved.

A Novel Approach to Study the Acute Physiological Effects of Caffeine and Chlorpromazine Following Oral Administration

Background

• Rodent studies historically focused on a single physiological system

• Integration of cardiovascular, respiratory, and neurobehavioral assessments would allow for more insight into how changes in one physiological system impact the others

• Advances in recent years have allowed combined models in large animals (i.e. JET/EMKA jacketed models)

• The release of a dual pressure catheter in a small animal model implant (model HD-S21) by Data Sciences International (DSI) opens up an opportunity to test a combined rodent model

Surgical Procedure

Surgical Procedure

• Prior to study, rats were implanted with a telemetry device (Model No. HD-S21, Data Sciences International (DSI), St. Paul MN).

• 1 pressure catheter was inserted into the abdominal aorta and advanced to a position caudal to the renal bifurcation. Another pressure catheter was inserted under the serosal surface of the esophagus in the thoracic cavity.

• 4x4 Latin square cross-over design [7 days between each treatment]

• Male rats (CRL:WI(HAN)) instrumented with telemetry devices for the measurement of arterial pressure, heart rate, ECG, respiratory rate, respiratory pressure, activity, and body temperature

• Each rat received oral doses of vehicle (distilled water) and caffeine at 3, 12, and 24 mg/kg

• Each rat received oral doses of vehicle (distilled water) and chlorpromazine at 2, 8, and 16 mg/kg

• Arterial pressures, ECG waveforms, respiratory rate, respiratory pressure, and activity were monitored continuously for 2 hours prior to dosing and up to 24 hours post-dose

Study Design

Dose dependant increase in heart rate at all dose levels up to 2 hours post dose.

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Caffeine (3 mg/kg)

Caffeine (12 mg/kg)

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Caffeine (3 mg/kg)

Caffeine (12 mg/kg)

Caffeine (24 mg/kg)

24mpk: 67.8 bpm; 19.3%

12mpk: 18.7%

3mpk: 10.2%

Effect of Caffeine on Heart Rate


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Caffeine (3 mg/kg)

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Caffeine (3 mg/kg)

Caffeine (12 mg/kg)

Caffeine (24 mg/kg)

24mpk: 61.9 bpm; 54.9%

12mpk: 30.0%

3mpk: 22.3%

Dose dependant increase in respiratory rate at all dose levels up to 2 hours post dose.

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Effect of Caffeine on Respiratory Rate


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Caffeine (3 mg/kg)

Caffeine (12 mg/kg)

Caffeine (24 mg/kg)


0 2 4 6 8 10 12 14 16 18 20 22 24

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Caffeine (3 mg/kg)

Caffeine (12 mg/kg)

Caffeine (24 mg/kg)

No statistically significant changes in pressure at any dose level.

Effect of Caffeine on Respiratory Pressure

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Effect of Caffeine on Activity

24mpk: 400%

12mpk: 489%

3mpk: 257%

Significant increases in activity in a dose dependant manner up to 3 hours post dose.

Effect of Caffeine on Activity

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Caffeine (3 mg/kg)

Caffeine (12 mg/kg)

Caffeine (24 mg/kg)

Small increases in body temperature in the mid and high doses up to 2 hours post dose, most likely due to the large increase in activity at those times.

Effect of Caffeine on Body Temperature

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Chlorpromazine (2 mg/kg)




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16mpk: 66.1 bpm; 54.9%

8mpk: 66.7%

An unexpected increase in heart rate in both the mid and high doses for up to 8 hours post dose (the duration of the light cycle after dosing). Heart rate was comparable to vehicle once lights went out and rats became more active.

Effect of Chlorpromazine on Heart Rate

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No changes in respiratory rate at any dose level. Very unexpected!

Effect of Chlorpromazine on Respiratory Rate

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Pressure


0 2 4 6 8 10 12 14 16 18 20 22 24

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No significant changes in respiratory pressure immediately post dose, though we do start to see some depressed pressures during the night cycle (hours 9-21 post dose), especially in the high dose.

Effect of Chlorpromazine on Respiratory Pressure

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16mpk: -231%

Once again we see no changes in activity until the night cycle, were we see some depression in the high dose.

Effect of Chlorpromazine on Activity

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A dose dependant decrease in core body temperature from hours 2-14 post dose.

Effect of Chlorpromazine on Temperature

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Results (Caffeine)

• Rats dosed with 24 mg/kg of caffeine showed the expected transient increase in heart rate (67.8 bpm; 19.3%) as well as increases in respiratory rate (61.9 bpm; 54.9%), and activity (400%). There was no apparent change in respiratory pressure.

• Rats given 3 and 12 mg/kg of caffeine also showed increases in heart rate (10.2%; 18.7%), respiratory rate (22.3%; 30.0%), and activity (257%; 489%) in a dose responsive manner

• Rats given chlorpromazine showed an increase in heart rate (66.1 bpm; 19.9%) and the expected decrease in activity (-231%) at a dose of 16 mg/kg.

• There was no apparent change in respiratory parameters following administration of chlorpromazine at any dose.

Results (Chlorpromazine)

Conclusions…

• Surgically feasible model

• Continuous 24 hour respiratory monitoring (time consuming)

• Reliable cardiovascular and neurobehavioral results for both caffeine and chlorpromazine

• Expected changes in respiratory parameters seen in caffeine dosed rats

• Unexpectedly, a decrease in respiratory parameters was not seen in chlorpromazine treated rats, thus further studies must be conducted to determine if the this combined model is able to detect decreases in respiratory rate with confidence.

Acknowledgements & References

• Dennis J. Murphy

• Safety Pharmacology staff at GlaxoSmithKline

• All studies were conducted in accordance with the GSK Policy on the Care, Welfare and Treatment of Laboratory Animals and were reviewed by the Institutional Animal Care and User Committee either at GSK or by the ethical review process at the institution where the work was performed.

1. Sgoifo, A., et al., “Electrode positioning for reliable telemetry ECG recordings during social stress in unrestrained rats.” Physiology and Behavior. 1996 Mar; 60(6):1397-1401. LINK

2. Lynch III, J. et al., “Comparison of methods for the assessment of locomotor activity in rodent safety pharmacology studies”, Journal of Pharmacological and Toxicological Methods, 64 (2011) 74-80. LINK

https://www.ncbi.nlm.nih.gov/pubmed/8946481

https://www.ncbi.nlm.nih.gov/pubmed/21406241

Thank You:

Brian M. RochePhD, DSP, DABT

Director of Safety Pharmacology,Charles River Laboratories

Jason D. Payseur

Senior Scientist – IVIVT, MSD Safety Pharmacology USGlaxoSmithKline

For additional information on the solutions presented in this webinar please visit www.datasci.com

http://insidescientific.com/

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Combining Cardiovascular, Respiratory and Neurobehavioral Endpoints for Efficient Study Design

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Transcript of Combining Cardiovascular, Respiratory and Neurobehavioral Endpoints for Efficient Study Design