The relation between metabolic and functional derangement in various cardiomyopathies has not been well characterized. This information was specifically sought in a spontaneous cardiomyopathic model. Metabolic and hemodynamic parameters were obtained in glucose-perfused beating hearts of 180-200-day-old cardiomyopathic Syrian hamsters and age-matched healthy animals. This period in the cardiomy...

Many nontropical rodent species display seasonal changes in both physiology and behavior that occur primarily in response to changes in photoperiod. Short-day reductions in reproduction are due, in part, to reductions in gonadal steroid hormones. In addition, gonadal steroids, primarily testosterone (T), have been implicated in aggression in many mammalian species. Some species, however, displa...

Previous studies have demonstrated a diminution in the bioactivity of the guanine nucleotide-binding regulatory protein that stimulates adenylyl cyclase (Gs) in hearts of the hypertrophic BIO 14.6 Syrian hamster. In this study, we measured functional activity and immunodetectable levels of Gs in a mutant strain of hamsters (BIO 53.58) that develop a dilated cardiomyopathy. Pathological studies ...

Exposure to short days (SD) induces profound changes in the physiology and behaviour of Siberian hamsters, including gonadal regression and up to 30% loss in body weight. In a continuous SD environment after approximately 20 weeks, Siberian hamsters spontaneously revert to a long day (LD) phenotype, a phenomenon referred to as the photorefractory response. Previously we have identified a number...

Changes in day length affect several measures of immunity in seasonally breeding mammals. In Siberian hamsters (Phodopus sungorus), short day lengths suppress specific secondary antibody responses to the keyhole limpet hemocyanin (KLH) antigen and enhance cutaneous delayed-type hypersensitivity (DTH) responses to dinitrofluorobenzene (DNFB). These experiments tested whether day length affects s...

Temperate and boreal mammals undergo seasonal changes in pelage that facilitate thermoregulation in winter and summer. We investigated photoperiodic influences on pelage characteristics of male Siberian and Syrian hamsters. Fur density (mg fur/cm2 skin) was measured by weighing the shavings of fur patches removed from the dorsal and ventral surfaces of hamsters maintained in long days (LDs) or ...

Pulpal conditions were studied in Chinese hamsters with hereditary diabetes mellitus, H-l-virus-modified hamsters, mice of the gray lethal mouse strain, polyoma-infected Swiss mice, mutation-diabetic mice, and rats with streptozotocin-produced diabetes. Degenerative pulpal changes in the Chinese hamsters and the polyoma-infected Swiss mice were often found in association with periodontal diseas...

The anti-inflammatory drug flurbiprofen speeds the repair of cigarette smoke-induced bronchial secretory cell metaplasia (SCM) in rats. We tested whether flurbiprofen would prevent or mitigate the development of elastase-induced bronchial SCM in hamsters. Twice daily injections of flurbiprofen (4 or 6 mg.kg-1.day-1) were begun immediately after intertracheal instillation of porcine pancreatic e...

Interactive media not only should enhance human-to-human communication, but also human-to-animal communication. We promote a new type of media interaction allowing human users to interact and play with their small pets (like hamsters) remotely via Internet through a mixed-reality-based game system “Metazoa Ludens”. To examine the systems effectiveness: Firstly, the positive effects to the hamst...

growth-inducing exercise in hamsters were studied by examining (a) dependence of this phenomenon on a specific activity device, (b) its species-specificity, and (c) features of the running pattern which produce optimal growth acceleration. Acceleration of growth by exercise occurs in hamsters running on either horizontal discs or in vertical wheels, and in gerbils running in rotating wheels, an...