Arylacetamides as peripherally restricted kappa opioid receptor agonists.

Analogues of the kappa (kappa) opioid receptor agonist, ICI 199441, were prepared. Ki values for these analogues at the cloned human kappa opioid receptor ranged from 0.058 to 25 nM. Trifluoromethylaryl derivatives were potent analgesics when administered subcutaneously in the rat and were more peripherally restricted than the parent compound, ICI 199441.

Increased expression of cell surface markers on endometrial gamma delta T-cell receptor+ intraepithelial lymphocytes induced by the local presence of the sheep conceptus.

PROBLEM: In sheep, gamma delta T-cell receptor (TCR)+ cells are a major lymphocyte subpopulation in the luminal epithelium of the uterine endometrium. During late pregnancy, this population of T cells increases in number and becomes more granulated. This study was performed to determine whether this apparent activation was induced by local effects of the conceptus or systemic effects of pregnancy. METHODS: The unilaterally-pregnant ewe, in which the conceptus is surgically confined to one uterine horn, was used to distinguish between systemic and local effects of pregnancy on function of endometrial gamma delta TCR+ intraepithelial lymphocytes. Lymphocytes collected from peripheral blood, and from the endometrial luminal epithelium of cyclic and unilaterally-pregnant ewes (day 140 of gestation) were analyzed by flow cytometry. RESULTS: As compared to gamma delta TCR+ lymphocytes in peripheral blood, gamma delta TCR+ intraepithelial lymphocytes from non-pregnant ewes had lower percentage of cells staining positive for CD25, CD44, and L-selectin. There was no effect of pregnancy on the percentage of gamma delta TCR+ peripheral blood lymphocytes staining positive for CD25, CD44, CD29, or L-selectin. Similarly, the percentage of intraepithelial lymphocytes staining positive for these antigens was similar for cells collected from cyclic ewes and cells from the nonpregnant uterine horn of unilaterally-pregnant ewes. In contrast, there was a higher percentage of CD25, CD44, CD29, and L-selectin+ cells for gamma delta TCR+ intraepithelial lymphocytes from the conceptus-containing uterine horn of pregnant ewes than for gamma delta TCR+ intraepithelial lymphocytes from the endometrium of cyclic ewes or from the nonpregnant uterine horn of pregnant ewes. CONCLUSION: The local presence of the conceptus causes changes in cell surface marker expression on endometrial gamma delta TCR+ intraepithelial lymphocytes during pregnancy. These changes may reflect conceptus-induced activation of this population of cells.

Effect of induced pyometra on luteal lifespan and uterine fluid concentrations of prostaglandins and interferons in cows.

The objective was to determine whether occurrence of persistent corpora lutea in cows with pyometra could be explained by accumulation of prostaglandins and interferons in the uterus. Pyometra was induced by treatment with hCG, followed by intrauterine infusions of iodine and Actinomyces pyogenes . Five of the seven treated cows developed pyometra as indicated by extended estrous cycles (30-37 + d) and presence of purulent uterine exudate at slaughter (Day 37 after estrus). Mean (+/- standard error) concentrations of prostaglandins E(2) and F(2alpha) for the cows with pyometra were 34.7 +/- 14.4 and 96.3 +/- 28 ng/ml, while the concentrations in uterine flushings in the remaining 2 cows averaged 1.85 +/- 0.7 and 0.9 +/- 0.2 ng/ml, respectively. Based on Western blotting, none of the cows had detectable concentrations of either interferon-alpha or interferon-tau in uterine secretions. In conclusion, pyometra results in increased uterine prostaglandin secretion. While increased secretion of cytokines associated with bacterial infection may be contribute to this effect, there was no evidence in this study to suggest that interferons are involved in the mechanism which causes persistence of the corpus luteum in bovine pyometra.

Enhancement of mitogen-induced lymphocyte proliferation in sheep.

Conditions were established to optimize the lymphocyte proliferation test in sheep, a species where proliferation under standard conditions is lower than for other species. Optimum proliferation of phytohemagglutinin-stimulated lymphocytes was achieved in TCM-199 supplemented with 5% (v/v) horse serum, 0.2 mM sodium pyruvate and 5 x 10(-5) M beta-mercaptoethanol. Proliferative responses in this medium were 2.5-fold higher or more than when using a standard medium (RPMI-1640 + 10% heat-inactivated fetal bovine serum). Lymphocytes cultured in medium containing horse serum also responded to concanavalin A as well as or better than lymphocytes cultured in medium with bovine serum. For both PHA and Con A, optimal incorporation of radioactivity was achieved when cells were pulsed with [3H-methyl]-thymidine 72 h after addition of mitogen. The medium based on TCM-199 + horse serum could support interleukin-2-induced proliferation. Furthermore, known inhibitors of lymphocyte proliferation in sheep were effective in inhibiting lymphocytes cultured in this medium.

Regulation of leucocyte subpopulations in the sheep endometrium by progesterone.

To determine whether progesterone causes a change in lymphocyte subpopulations in the endometrium, frozen sections of intercaruncular and caruncular endometrium from ewes receiving daily i.m. injections of 100 mg/day progesterone were evaluated by immunohistochemistry for the presence of lymphoid cells bearing CD45, major histocompatibility complex (MHC) class II, CD45R, CD4 and CD8 antigens. The pattern of lymphocyte distribution in the uterine endometrium of untreated ewes was similar to previous reports. Progesterone treatment, particularly after 60 days, caused reductions in numbers of CD45+ cells in the glandular epithelium and associated subepithelial stroma, MHC class II+ cells in all regions of the intercaruncular endometrium and CD45R+ cells in all epithelial regions of intercaruncular and caruncular endometrium. These data demonstrate a role for progesterone in regulating migration or proliferation of endometrial lymphocyte populations; this action of progesterone may represent an important mechanism by which progesterone modifies uterine immune function.