Research uses for hamsters

What are commonly hamsters models for?

What are commonly hamsters models for?

Carcinogens/Tumors

Metabolic Diseases

Infectious Diseases

Immunology

Radioresistance

Human Fertility

Virus – induced tumor production

Common carcinogen and oncology studies in hamsters?

1. cheek pouch neoplasia for oral cancer development

2. pancreatic ductal adenocarcinoma through administration of nitrosamines

3. Simian virus 40 role in human cancer

4. Effects of exogenous estrogen on tumor formation

   100% of males develop renal tumors – good model human renal cancer

5. Human adenoviral cancer therapeutic research

6. Respiratory tract tumors

   Nonsmall cell lung carcinoma

What does administration of nitrosamines and PGHAM-1 induce in hamsters?

Pancreatic ductal adenocarcinoma

What does 4-(methylnitrosamino)-1-(3-pyridyl1)-1-butanone induce in hamsters?

respiratory tract tumors

What does streptozotocin (STZ) or alloxan induce in hamsters?

diabetes mellitus

What are the dietary recommendations for induction of type 2 diabetes in hamsters?

↑ fat (15%), modest cholesterol (0.12%)

How to induce cholelithiasis?

induced with ↑ cholesterol OR sucrose-rich diet

What species have similar lipid metabolisms to humans?

hamsters, good models for atherosclerosis research

What type of cardiomyopathies are hamsters good models for?

Model DCM and HCM

How is emphysema and COPD induced in hamsters?

intratracheal porcine pancreatic elastase and decrease diets in CU

What disease is hamsters the only spontaneous model for?

Atrial thrombosis in aged left atrium

What are hamsters good infectious disease models for?

Leishmania infantum à polymositis, inflammatory myopathy model

Mycoplasma pneumoniae à localized infection respiratory tract model

Mycobacteria, C. difficle, Treponema pallidum (syphilis), Toxoplasma, Babesia, Leprosy, atypical tuberculosis, Leptospirosis

Viral: Hantavirus Pulmonary Syndrome, Coronavirus (SARS), VEE, St. Louis Encephalitis, Yellow fever, Herpes, Machupo/Junin

Fungal: Histoplasmosis, Cryptococcus, Blastomycosis

Prion: Scrapie, TME, Creutzfeldt-Jakob, Gerstmann-Staussler syndrome Slow, progressive degenerative disease CNS

Why are hamsters good models for immunobiology?

Neonatal hamster immunologically immature

Thymus at birth = 16-day old mouse embryo

Lack suppressor T cells

Atypical cytotoxic T cells

MHC (Hm-1) gene similarity

Skin grafts readily taken

What is the best day during pregnancy to start studying teratogens?

day 8

Why are hamster oocytes good for studying repro in humans?

Hams oocyte penetrable by HUMAN sperm. Analyzes ability sperm to capacitate eggs, acrosome reaction and fuse w/ oocyte

How many chromosomes do Cricetulus griseus have?

22

Average size, life span of Cricetulus griseus?

39 - 46 grams, 2.5 - 3 years

Breeding and behavioural challenges with Cricetulus griseus?

Females often kill males during breeding, very aggressive in general so need to be housed singly.

Sexual maturity, gestation, and length of estrus cycle for Cricetulus griseus?

8 - 12 weeks, 20.5 day gestation, 4 day estrus cycle

Characteristics of newborn Cricetulus griseus?

eyes/ ears open 10 - 14 days, hair 3-4 days, incisors at birth

Characteristics of diabetes mellitus in Cricetulus griseus?

Similar to Type 1 DM humans

Clinical Signs: PU/PD, urine stain/scald, blindness, conjunctivitis, alopecia, sudden death, female infertility/abortions

RECESSIVE - 100% of offspring affected if parents are ketotic

It is spontaneous

Most common neoplasms of C. griseus?

Uterine adenocarcinoma

Hepatomas

Most common research model for C. griseus?

#1 use is Chinese Hamster Ovary (CHO) cell lines

average size, gestation, sexual maturity and number of chromosomes of Cricetulus migratorius?

Medium-sized – 40 to 80 grams

Diploid chromosome # 22

~ 7 weeks sexual maturity

Gestation: 18-19d, 5-7 litter size

Common models for Cricetulus migratorius?

Susceptible to mutagenic and carcinogenic agents (tend to see hepatocellular carcinomas)

Cytogenetics 

Oncology

Prion Dz studies

Cricetus cricetus (European Hamster) gestation, size, estrus, chromosome number and size in comparison to syrian (is there sex differences)?

Large (3x size of Syrian) males > females

Gestation = 15-17 days

Diploid Chromosome = 22

Very aggressive/easily frightened

4 stage estrus (4-6 days)

What type of hibernators are Cricetus cricetus?

True hybernators

Cricetus cricetus and gonad development during hibernation?

gonadal regression at 15-15.5hr photoperiod

Spontaneous tumors in Cricetus cricetus?

Leukemias/lymphomas, adrenal pheochromocytomas, granulosa cell tumors (females)

Where do C. cricetus get cysts, are there sex differences?

Develop cysts w/in peritoneal cavity, esp. liver females > males

Models for C. cricetus?

Hibernation

Lung tumors and smoke inhalation: Naturally low incidence spontaneous pulmonary neoplasia

Susceptible to N-diethylnitrosamine (DEN): Induces respiratory tumors

Pneumonic for memorizing models for European hamsters?

Europeans like to smoke and sleep

What are the two djungarian species of hamster?

Phodopus sungorus (Siberian dwarf)
Phodopus campbelli (Russian dwarf)

What is unique about the dwarf hamster repro cycle with regards to length?

Shortes repro cycle of any eutherian mammal?

Size, chromosome number, gestation, estrus cycle and parturition / second mating timing of podopus spp.

Size: Male - 40 - 50 g, Female 18 - 25 g, chromsome number 28, gestation 18 days, estrus 4 days, mate on day of parturition and deliver 2nd as weaning 1st.

Which podopus spp does monogamous parental care?

P. campbelli- monogamous parental care

P. sungorus - male does NOT help with care of young

Are podopus females aggressive?

No

Do phodopus spp hibernate?

no

Where do podopus get neoplasia, is it common and what is the cancer?

High incidence of neoplasia oral cavity, skin, mammary glands in Russian dwarf hamsters (> females). Fibrosarcoma

Common repro finding in P. campbelli when females not bred?

Cystic ovaries

Common models for podopus species?

Pineal gland studies on melatonin/effects of photoperiod

susceptible to carcinogens, infected by oncogenic viruses

Used extensively in behavior and reproductive physiology studies