An Immunoregulatory Role for Complement Receptors in Murine Models of Breast Cancer.

The complement system has demonstrated roles in regulating tumor growth, although these may differ between tumor types. The current study used two murine breast cancer models (EMT6 and 4T1) to investigate whether pharmacological targeting of receptors for complement proteins C3a (C3aR) and C5a (C5aR1) is protective in murine breast cancer models. In contrast to prior studies in other tumor models, treatment with the selective C5aR1 antagonist PMX53 had no effect on tumor growth.

A Potential Link between the C5a Receptor 1 and the β1-Adrenoreceptor in the Mouse Heart.

Purpose: Inflammation may contribute to the pathogenesis of specific cardiovascular diseases, but it is uncertain if mediators released during the inflammatory process will affect the continued efficacy of drugs used to treat clinical signs of the cardiac disease. We investigated the role of the complement 5a receptor 1 (C5aR1/CD88) in the cardiac response to inflammation or atenolol, and the effect of C5aR1 deletion in control of baseline heart rate in an anesthetized mouse model.

Methods: An initial study showed that PMX53, an antagonist of C5aR1 in normal C57BL6/J (wild type, WT) mice reduced heart rate (HR) and appeared to have a protective effect on the heart following induced sepsis.

Myocardial collagen deposition and inflammatory cell infiltration in cats with pre-clinical hypertrophic cardiomyopathy.

The histological features of feline hypertrophic cardiomyopathy (HCM) have been well documented, but there are no reports describing the histological features in mild pre-clinical disease, since cats are rarely screened for the disease in the early stages before clinical signs are apparent. Histological changes at the early stage of the disease in pre-clinical cats could contribute to an improved understanding of disease aetiology or progression. The aim of this study was to evaluate the histological features of HCM in the left ventricular (LV) myocardium of cats diagnosed with pre-clinical HCM.

Evaluation of a technique to measure heart rate variability in anaesthetised cats.

Analysis of heart rate (HR) and heart rate variability (HRV) are powerful tools to investigate cardiac diseases, but current methods, including 24-h Holter monitoring, can be cumbersome and may be compromised by movement artefact. A commercially available data capture and analysis system was used in anaesthetised healthy cats to measure HR and HRV during pharmacological manipulation of HR. Seven healthy cats were subjected to a randomised crossover study design with a 7 day washout period between two treatment groups, placebo and atenolol (1mg/kg, IV), with the efficacy of atenolol to inhibit β1 adrenoreceptors challenged by epinephrine.

Plasma pharmacokinetics of alfaxalone after a single intraperitoneal or intravenous injection of Alfaxan(®) in rats.

Alfaxalone (3α-hydroxy-5α-pregnane-11, 20-dione) is a neuroactive steroid with anaesthetic properties and a wide margin of safety. The pharmacokinetic properties of alfaxalone administered intravenously and intraperitoneally in rats (n = 28) were investigated. Mean t(1/2elim) for 2 and 5 mg/kg i.