We have examined the effects of chronic voluntary running for 30 d on the levels of nerve growth factor inducilble-B (NGFI-B) and neuron-derived orphan receptor 1 (NOR1) mRNAs in Fischer and Lewis rats. The aim was to compare the addiction-prone Lewis rat strain to the Fischer strain in a plausible model for natural reward. The Lewis strain ran markedly more than the Fischer strain, as indicate...

BACKGROUND AND AIM Green fluorescent protein (GFP) is a widely used molecular tag to trace transplanted cells in rodent liver injury models. The differing results from various previously reported studies using GFP could be attributed to the immunogenicity of GFP. METHODS Hepatocytes were obtained from GFP-expressing transgenic (Tg) Lewis rats and were transplanted into the livers of wild-type...

Since the incidence and growth of adenofibroma of the mammary gland are known to be affected by the ovarian hormones, the observation oi Geschickter and Lewis (1-5) that this tumor may contain large amounts of estrogenic and gonadotropic hormones is of fundamental interest. They suggest that since adenofibroma is composed of the elements normally stimulated by estrin, namely the ducts and perid...

The Lewis (LEW) and Fischer 344 (F344) inbred rat strains react differentially to acute morphine administration for a variety of behavioral and neurochemical measures. Investigations into effects of chronic morphine are less common, and investigations assessing dependence have been limited to those utilizing antagonist-precipitated withdrawal. The present experiment extended these assessments b...

We have identified large quantities of a water-soluble, non-RT1.A class I MHC molecule in the serum of the DA rat strain, with a similar molecule being found in aqueous extracts of DA liver. The non-RT1.A class I molecules have heavy chains of 41 kD, which is smaller than RT1.A class I molecules isolated from liver membranes (45 kD) but larger than water-soluble RT1.A class I molecules previous...

When using rats in pain research, strain-related differences in outcomes of tests for pain and nociception are acknowledged. However, very little is known about the specific characteristics of these strain differences. In this study four phylogenetically distant inbred rat strains, i.e. Wistar Kyoto (WKY), Fawn Hooded (FH), Brown Norway (BN) and Lewis (LE), were investigated in different tests ...

Lewis (LEW) and spontaneously hypertensive rats (SHR) have been shown to differ in a series of fear-related behaviours measured in different anxiety/emotionality tests. In the present study, we have investigated some of the genetic mechanisms underlying these differences. To this end, male and female rats from the two inbred strains were crossed to produce two parental (LEW and SHR), two F1 (LE...

The purpose of this study was to better understand the role of ocular pigmentation and genetics in light-induced retinal damage. Adult pigmented [Long Evans (LE) and Brown Norway (BN)] and albino [Sprague Dawley (SD) and Lewis (LW)] rats were exposed to a bright cyclic light for 6 consecutive days and where compared with juvenile animals exposed to the same bright light environment from postnat...

An immunogold-silver enhancement technique, which combines effective labeling of viable isolated islets with the ultrastructural resolution of cytological details, was applied in electron microscopy to identify major histocompatibility complex (MHC) structures on islet cells. Incubation of freshly isolated islets from CAP (RT1c) and LEW (RT1l) rats with OX18, an MHC class I antibody, showed str...

Yields and function of isolated islets vary considerably in spite of the introduction of new or improved methods for isolation. In most studies, these variations have been attributed to inadequacies of the applied collagenase preparations. However, when we retrospectively analyzed our rat islet isolations, we found large variations in yield and function in spite of application of identical coll...