TetraQ offers a range of techniques for investigating the efficacy of potential drugs in development, with a focus on in vivo models. Several of these models can be conducted in a "screening" format to minimise costs and provide proof-of-concept data for a panel of compounds. Candidate confirmation studies typically involve a more thorough examination of efficacy and disease models are chosen based on their acceptance in the relevant field. To see where efficacy testing fits with other preclinical testing, see the TetraQ Drug Development Roadmap.

In vitro models

• Pain
• Multiple Sclerosis (mouse)
• Obesity and Diabetes
• Parkinson’s Disease
• Alzheimer’s Disease
• Ventilatory function
• Gastrointestinal function
• Arthritis (in validation)
• IBD (future model)

• intravenous (i.v.)
• subcutaneous (s.c.)
• intraperitoneal (i.p.)
• oral (p.o.)
• intragastric (i.g.)
• intradermal (i.d.)
• intrathecal (i.t.)
• intracerebroventricular (i.c.v.)
• specific brain regions

Prevention and reversal protocols can be designed.

In vitro Models

TetraQ offers two kinds of in vitro screening assays:

• Opioid receptor binding assay:
  • Specific for mu, delta or kappa receptor subtypes
  • Calculation of binding affinity

• Opioid receptor function assay:
  • cAMP inhibition
  • MAPK activation
  • Agonist/antagonist testing and EC50/IC50 measurement

• Real-time PCR
  in vitro assays in other disease areas are able to be sourced from TetraQ's partners.

Pain Models

TetraQ has a wealth of experience in conducting a wide range of pain models in rats. Led by Professor Maree Smith, a renowned pain researcher, the efficacy team is highly skilled and well equipped to assess the potential analgesic effects of a novel drug. We routinely use “gold standard” techniques in behavioural pain assessment, in addition to applying advanced surgical skills.

Most pain models can be performed in both rats and mice.

Pain Models:

• Pain sensitivity and perception:
  • mechanical sensitivity to noxious and non-noxious stimuli
  • thermal sensitivity to noxious stimuli

• Acute stimulus-evoked pain models:
  • sensitivity to persistent pain from formalin injection

• Acute and chronic inflammatory pain models:
  • Capsaicin: the administration of capsaicin induces acute inflammation, hyperalgesia and allodynia in the injected paw
  • Postsurgical pain (Brennan model)- surgical incision in the hindpaw induces acute inflammation, hyperalgesia and allodynia
  • FCA: administration of Complete Freunds Adjuvant induces chronic unilateral inflammation, hyperalgesia and allodynia in the injected paw

• Neuropathic pain models:
  • Chronic Constrictive Injury (CCI): involves the tying of four loose ligatures around the sciatic nerve. This peripheral nerve injury results in the development of mechanical (tactile) allodynia in the ipsilateral hindpaw
  • Painful diabetic neuropathy (PDN): involves streptozotocin (STZ)-induced diabetes which is characterized by tactile allodynia after ~ 6 wks of STZ administration.

Pain Tests:

• von Frey hairs (or filaments) are used to assess mechanical paw withdrawal threshold. After injury, they are used to assess mechanical allodynia (increased sensitivity to a non-noxious stimulus such as light pressure or touch).
• Tail flick test primarily assesses the spinal antinociceptive (pain relief) response to noxious thermal stimuli, using either a tail flick, or tail withdrawal protocol.
• Hotplate test primarily assesses the supraspinal antinociceptive (pain relief) response to a noxious thermal stimulus.
• The plantar paw thermal latency test (Hargreaves test) is used to quantify thermal hyperalgesia in injured rat hindpaws.
• Paw pressure test (Randall-Sellito) assesses mechanical paw withdrawal threshold in response to application of noxious pressure to the rat hindpaw.
• Incapacitance meter can assess the guarding response in animals with an injured hindpaw
• Formalin test assesses persistent nociceptive pain sensitivity.

Multiple Sclerosis

TetraQ currently offers a mouse model of Multiple Sclerosis. We use a protocol that induces mild, relapsing-remitting experimental autoimmune (allergic) encephalomyelitis (EAE) by an injection of myelin oligodendrocyte glycoprotein (MOG35-55) and an adjuvant. The result of induction of EAE in the mice is temporary bouts of paralysis which occur in varying degrees in the limbs, characterized behaviourally by assessing ascending paralyses of the hindlimbs using a slightly modified standard scoring paradigm.

Obesity and Diabetes

Obesity

TetraQ has access to a colony of obese Zucker rats. Full food consumption and body weight curves are available for these animals and the effects of drugs on these parameters can be assessed.

Diabetes

Assessment of the effects of drugs in a reproducible rat model of type-1 diabetes that has been characterised for 26 weeks (STZ-induced)

Parkinson’s Disease

TetraQ has recently developed a model to measure the effects of drugs on Parkinson’s disease. Symptoms of Parkinson’s disease are induced in rats using a well accepted model, which involves the injection of the nerve cell toxin, 6-hydroxydopamine (6-OHDA) into the nigrostriatal dopaminergic pathway of the brain to induce either a unilateral or bilateral lesion (s) followed by behavioural testing.

Behavioural Tests:

• Apomorphine-Induced Turning (unilateral only): measures rotational ability
• Rotarod: measures the ability for the animal to walk on a rotating drum
• Gripstrength: measures forepaw and/or hindpaw gripping strength.
• Righting reflex: measures the ability to regain the prone position
• Open field locomotor activity test: measures total activity, discrete movements, distance travelled and rearing.

Alzheimer’s disease

Alzheimer’s disease symptoms are induced by the administration of aggregated ßamyloid (1-42) into the hippocampus of rats. This model is well accepted as an indicative model for Alzheimer’s disease symptoms. Protocols to measure the prevention as well as the reversal of symptoms can be designed. The effects of the drug are measured using a variety of behavioural tests and in vitro analysis.

Behavioural tests:

• Morris Water Task: measures spatial learning and memory.
• T Maze: assesses working spatial memory as well as reference memory
• Passive avoidance: measures tendency to escape from an illuminated area into a dark one (step-through method).

in vitro analysis:

• Tissue can be removed and analysed for histological labelling.

Gastrointestinal function

Gatrointestinal motility can be assessed in rats using an oral gavage of a charcoal solution

Constipation can be measured as an inhibition of ricinus oil-induced diarrhoea

Ventilatory function

Ventilatory function can be assessed using whole body plethysmography under resting conditions and during short periods of hypoxia, hyperoxia and hypercapnia

Arthritis

For screening purposes a rat model of immune-mediated monoarticular arthritis has been developed so that it can be utilized to assess the potential anti-inflammatory and anti-arthritic ability of potential novel compounds.

TetraQ plans to develop the collagen-induced model of arthritis in rats with histopathological examination of the joint structures (CAIA model of rheumatoid arthritis).

Inflammatory bowel disease

TetraQ are developing an animal model of hapten-induced experimental inflammatory bowel disease (IBD: Crohn’s disease or Ulcerative Colitis)