The cardiovascular and thermoregulatory systems are considered to be susceptible in the aged population, but little is known about baseline cardiac and thermoregulatory homeostasis in rodent models of aging. Radiotransmitters were implanted in male, Brown Norway rats obtained at 4, 12, and 24 months to monitor the electrocardiogram (ECG), interbeat interval (IBI), heart rate (HR), core temperat...

We examined in rat pups the relation between the decline of suckling and the emergence of independent ingestion, and the role of milk delivery conditional on nipple attachment in the maintenance of suckling. Fifteen-day-old litters were reared for either 5 or 10 days, and 20-day-old litters for 5 days by either a thelectomized (no nipples), ligated (nipples but no milk), or intact (nipples and ...

Method Specific antibodies were raised in a Brown Norway (BN) rat model of food allergy. BN rats were dosed either (1) intraperitoneally (i.p.) with the purified native cow’s milk allergens with or without the use of Al(HO)3 as adjuvant or (2) orally with skimmed milk powder without the use of adjuvant. The specific IgG1 and IgE antibody responses were analysed against native and denatured alle...

The mammalian epididymis is the site where spermatozoa are matured and then stored. Though many studies have described epididymal functions and their regulation, little is known about how aging affects this tissue. The Brown Norway rat, which does not show the many age-related pathologies common to other rat strains, was used as a model to study aging of the epididymis. The present study was de...

Warfarin resistance in the Norway rat (Rattus norvegicus) has been studied over the past 30 years. To determine the status of this resistance phenomenon wild Norway rats were collected from Colorado and Chicago, Illinois. As reported previously, warfarin resistance in the Chicago area exceeds 50%, while rats from Colorado remain very susceptible to warfarin. The theory that true genetic resista...

Two experiments were conducted to investigate the role of milk availability in the development of independent feeding and drinking in the Norway rat pup. Beginning on Day 14 postnatally, pups were exposed to different levels of milk supply by changing litter size from 8 to 4 versus 12 pups (Experiment 1) or limiting temporally the pups' access to a lactating dam to 8, 14, or 24 hr daily (Experi...