The myelin basic protein-specific T cell repertoire in Lewis rats: T cell receptor diversity is influenced both by intrathymic milieu and by extrathymic peptide presentation.

In the Lewis rat, the T lymphocyte response to guinea pig myelin basic protein (MBP) is focused almost exclusively on epitopes nested in the MBP peptide sequence p68-88, and is dominated by T cell receptors (TCR) using Vbeta8.2 gene elements, together with short N(D)N regions. Here we analyzed MBP-specific TCR from Lewis T cells differentiating in chimeric thymuses of Lewis rat/SCID mouse chimeras, in the absence of an intact rat thymic microenvironment (SCID(FL) mice).

Prodynorphin gene expression in spinal cord is enhanced after traumatic injury in the rat.

Levels of mRNAs coding for prodynorphin (Pro-Dyn) and proenkephalin (Pro-Enk) as well as the levels of immunoreactive (ir)-dynorphin (Dyn) and (ir)-Met-enkephalin (Met-Enk) were measured in the spinal cord of rats, 65 h following transection or injury of the spinal cord at the T6 spinal segment. Levels of both Pro-Dyn mRNA and of ir-Dyn were significantly increased between 60 and 150%, above control levels in the whole spinal cord, whereas those of Pro-Enk mRNA and of ir-Met-Enk remained unchanged. The increase in spinal levels of Pro-Dyn mRNA were highest in the areas close to the side of transection and indicate an involvement of the Pro-Dyn opioid system in the response to spinal injury and transection.

Prodynorphin gene expression is enhanced in the spinal cord of chronic arthritic rats.

The influence of chronic arthritic pain upon the levels of mRNA encoding prodynorphin (mRNADYN) in the spinal cord of rats was evaluated by use of the RNA blot technique. Rats were rendered arthritic by inoculation of the tail-base with a suspension of Mycobacterium butyricum. Three weeks post inoculation, levels of mRNADYN revealed a pronounced alteration in arthritic rats by a factor of greater than or equal to 2.

Localization of prodynorphin messenger rna in rat brain by in situ hybridization using a synthetic oligonucleotide probe.

An in situ hybridization technique has been developed to study the distribution of messenger RNA (mRNA) encoding prodynorphin (proenkephalin B) in sections of rat brain. A 100-mer oligonucleotide was used as a template to synthesize a 32P-labelled DNA probe complementary to the coding region of rat prodynorphin mRNA. Using this probe, dense labelling was observed in the supraoptic and paraventricular nuclei of the hypothalamus, in the striatum and in the dentate gyrus.

Stress-induced alterations in the levels of messenger RNA coding for proopiomelanocortin and prolactin in rat pituitary.

Acute stress promotes the secretion of prolactin (PRL) and of proopiomelanocortin (POMC)-derived peptides, adrenocorticotropic hormone and beta-endorphin, from the pituitary into the systemic circulation. The present study evaluates the influence of recurrent stress upon the biosynthetic activity of cells secreting these hormones in the rat. Chronic, intermittent, electrical foot-shock (3 mA,1 s duration, every 5 s for 30 min, twice daily) over a period of 1, 3 or 7 days caused an increase in messenger ribonucleic acid (mRNA) levels coding for POMC in the anterior pituitary.