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U S Shah

Publications and source records attributed to U S Shah.

8 recordsLinked to original sources
PubMed2001

Bimodal inhibition of connexin 43 gap junctions decreases ACTH-induced steroidogenesis and increases bovine adrenal cell population growth.

In order to elucidate the role of gap junctions in adrenal cell responses, we measured the effect of inhibiting gap junctions with 18-alpha glycerrhetinic acid (GA; a potent inhibitor of cell-cell communication) and connexin antisense transfection on cell proliferation and adrenocorticotropin (ACTH)-stimulated steroidogenesis. In these experiments we utilized a bovine adrenocortical cell (SBAC) population, which responds to ACTH treatment with a dose-dependent increase in steroid production, an increase in connexin 43 (alpha(1)-Cx43) gap junction protein concentrations, and a decrease in cell population growth. SBAC cell populations treated with GA had increased growth rates, decreased ACTH-stimulated steroidogenesis, but no reduction in alpha(1)-Cx43 gap junction protein contents. In contrast, when SBAC cells were transfected with alpha(1)-Cx43 antisense cDNA, gap junction protein concentration was dramatically reduced as expected, unlike the GA-treated cell populations. Cell populations transfected with alpha(1)-Cx43-antisense also exhibited increased growth rates and a decreased steroidogenic response to ACTH treatment as compared with control or vector-only transfected cell populations. The decreased responsiveness and increased number of cells in the population after gap junction function was decreased by either GA treatment or antisense transfection, suggests that gap junctions may be necessary factors in ACTH-stimulated responsiveness and growth control in the adrenal gland.

Adrenal Glands↗
PubMed1997

The role of alpha1 (connexin-43) gap junction expression in adrenal cortical cell function.

To investigate the relationship between adrenal cell function and gap junction expression, a bovine adrenal cell line (SBAC) was studied. Western blot and immunocytochemical techniques were used to demonstrate gap junction expression in SBAC cell populations. Cells expressed alpha1 (connexin 43) gap junction protein at points of cell-to-cell contact. Gap junction number and size increased in populations treated with ACTH (40 mU/ml) or dibutyryl cAMP (DbcAMP, 1.0 mM). Treatment with either ACTH or DbcAMP increased steroid production and cAMP levels. SBAC cell number, however, decreased in ACTH- or DbcAMP-treated populations. The number of cells increased in cultures transfected with alpha1-antisense complementary DNA. Neither ACTH nor DbcAMP treatment decreased cell number or increased steroidogenesis in alpha1-antisense complementary DNA-transfected cell populations. However, cell populations in which gap junctions were inhibited retained the capacity to increase cAMP production in response to ACTH (40 mU/ml) treatment. Hormone-stimulated gapjunction expression and cell communication may represent an important factor in adrenal gland function and control of proliferation.

Adrenal Cortex↗
PubMed1991

Conversion of a cyclooxygenase (CO) inhibitor into a 5-lipoxygenase (LO) inhibitor: a general route to novel orally active anti-inflammatory and anti-allergy drugs.

Previously, the conversion of a CO inhibitor, naproxen, into an orally active 5-LO inhibitor, Wy-50,295, by covalent attachment of a quinoline group was reported. The authors now report the extension of this transformation to other CO inhibitors. Replacement of an existing substituent or a hydrogen in sulindac, etodolac, carprofen, diclofenac, oxaprozin, des-alpha-methyl-ketoprofen, or des-alpha-methyl-flurbiprofen by a methoxyquinoline group afforded new hybrid structures which were orally active 5-LO inhibitors in the rat RPAR (reverse passive Arthus reaction) assay. In contrast to Wy-50,295 which is a selective 5-LO inhibitor, some of these new hybrids were dual inhibitors of 5-LO and CO. For example, the quinoline-etodolac hybrid WAY-120,739, (1,8-diethyl-1,3,4,9-tetrahydro-6-(2-quinolinylmethoxy)pyrano [3,4-b]indole-1-acetic acid) was a dual inhibitor of 5-LO and CO (91% and 47% inhibition, respectively at 10 microM, rat PMN). In contrast, the quinoline-flurbiprofen hybrid WAY-121,006, (3-fluoro-4'-(2-quinolinylmethoxy)-[1,1'-biphenyl]-4-acetic acid), the quinoline-oxaprozin hybrid, WAY-120,460, (5-phenyl-4-[4-(2- quinolinylmethoxy)phenyl]-2-oxazolepropanoic acid) and the quinoline-carprofen hybrid WAY-120,429 (alpha-methyl-6-(2-quinolinylmethoxy)-9-(2-quinolinylmethoxy)-9H- carbazole-2-acetic acid) were purely 5-LO inhibitors (100%, 96% and 92% inhibition of 5-LO at 10 microM, rat PMN, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMedDate not supplied

Modulation of adrenal gap junction expression.

To increase our knowledge of the role of peptide hormone stimulation in gap junction protein expression and adrenal cortical cell function, primary rat adrenal cortical cells were treated with adrenocorticotropin, and gap junction proteins were measured. Immunocytochemistry and western blot analysis were used to detect and characterize gap junction type and distribution. The gap junction protein, connexin 43 (alpha 1), was detected. Analysis of six connexin protein types did not reveal gap junction species other than alpha 1. Cells of the inner adrenal cortical zones, zonae fasciculata and reticularis, were demonstrated to have the highest number of gap junctions per cell in the adrenal gland. Adrenal cell cultures enriched for the two inner cortical adrenal zones were established and demonstrated also to express alpha 1 gap junction protein. Adrenocorticotropin (40 mUnits/ml) and dibutyryl cyclic adenosine monophosphate (1 mM) treatments increased alpha 1 gap junction protein levels and decreased cell proliferation rates in the cell cultures. The results are consistent with the hypothesis that gap junction expression can be regulated by adrenocorticotropin acting through the second messenger cyclic adenosine monophosphate. It can be suggested that gap junction expression in the adrenal gland may be under hormonal influence, and that gap junctions serve as passage for movement of molecules involved in control of cell proliferation.

Adrenal Glands↗