Selective transcription and DNase I protection of the rat prolactin gene by GH3 pituitary cell-free extracts

Prolactin (PRL) is a member of the growth hormone gene family that is specifically expressed in the lactotroph cells of the anterior pituitary. Whole cell extracts have been prepared from cultured GH3 rat pituitary tumor cells to study lactotroph-specific expression of the rat PRL (rPRL) gene in an in vitro transcription assay. The human alpha 1-globin and Rous sarcoma virus promoters efficiently initiate transcription in both HeLa and GH3 cell extracts, whereas the rPRL promoter containing 425 base pairs of 5' flanking DNA is active only in GH3 pituitary cell-free extracts. Transcription of the rPRL gene was reconstituted in HeLa cell extracts by the addition of GH3 cell extracts. DNase I digestion of the rPRL promoter reveals two protected regions centered at positions -55 (I) and -160 (III) that are GH3 cell-specific and rPRL promoter-selective. These "footprints" overlie a highly conserved 8-base-pair motif, CCTGATAATA. By contrast, footprint II at position -125 is common to both HeLa and GH3 cell extracts and overlies a 15-base-pair sequence found in all members of the growth hormone gene family. Thus, GH3 pituitary cell-free extracts selectively transcribe the rPRL gene and contain cell-specific factors that directly interact with the rPRL promoter. These studies provide useful assays to further identify, purify, and characterize pituitary-specific transcription factors and to address the biochemical mechanisms involved in rPRL gene expression.

A New Alkaloid Ajmalimine from the Roots of Rauwolfia serpentina

A new indole alkaloid ajmalimine has been isolated from the roots of RAUWOLFIA SERPENTINA collected in Thailand. Its structure, 21-(trimethoxybenzoyl)-ajmaline, was established by spectroscopic and chemical means.

Isolation and Structure of Neriumol and Nerifol from the Leaves of Nerium odorum

From the fresh, undried, uncrushed leaves of NERIUM ODORUM, two hydroxy acid methyl esters, neriumol and nerifol, have been isolated and their structures established as methyl (7 S,16)-dihydroxyhexadeca-8 Z-enoate and methyl (8,16)-dihydroxyhexadecanoate, through chemical and spectroscopic methods.

Cardiac function in alcohol-associated systemic hypertension

The pathogenesis of alcohol cardiomyopathy is obscure. Because systemic hypertension is observed in one-third of alcoholics, the relation of this finding to left ventricular (LV) function was analyzed in 66 alcoholics (26 with a blood pressure of 160/95 mm Hg or higher) 4 to 5 days after alcohol withdrawal. Hypertensive alcoholics had a more abnormal ratio of preejection period/LV ejection time (PEP/ET) (0.398 +/- 0.01 vs 0.35 +/- 0.01, p less than 0.02) than normotensive alcoholics (matched normal 0.290 +/- 0.01). Hypertensive alcoholics (transitory hypertension) with blood pressures of 120/80 mm Hg or less at time of study also had more abnormal PEP/LVET than matched normotensive alcoholics (0.415 +/- 0.03 vs 0.331 +/- 0.01, p less than 0.05). In both hypertensive (77 +/- 6 dynes/cm2 X 10(3)) and normotensive alcoholics (67 +/- 4 dynes/cm2 X 10(3) LV stress was elevated (normal 46 +/- 3 dynes/cm2 X 10(3), both p less than 0.02). However, LV mass was not increased (hypertensive 96 +/- 4 g/m2; vs normotensive 100 +/- 4 g/m2; (normal 92 +/- 5 g/m2), resulting in a markedly increased stress to mass ratio (hypertensive 0.8 +/- 0.06; Normal 0.05 +/- 0.05, p less than 0.02). Hypertensive alcoholics also had LV "hyperfunction," with an increased stress/LV end-systolic volume ratio (1.7 +/- 0.1 vs 1.3 +/- 0.1 dynes/cm2 X 10(3)/ml, p less than 0.02). Thus, hypertensive alcoholics, even those with transitory hypertension, have more abnormal cardiac function than normotensive alcoholics. Presence of hypertension with hyperdynamic LV features may be a prelude to heart failure.

Studies in the Chemical Constituents of Azadirachta indica Part II: Isolation and Structure of the New Triterpenoid Azadirachtol

A new triterpenoid named azadirachtol ( 1) has been isolated from the fruits of AZADIRACHTA INDICA Juss. (neem) of which the structure is reported on the basis of chemical and spectral data. Azadirachtol appears to be the first apo-tirucallol (apo-euphol) derivative possessing an eight carbons side-chain with an oxygenated ring system isolated from neem. Moreover, it is the first instance of the isolation of an 11-hydroxy triterpenoid from any of the various parts of neem.