Beta-2 adrenoceptor blocking activity of penbutolol and propranolol at very low doses

BALB/c mice immunized with bacterial levan (BL) produce an immune response that fails to generate antibody expressing the idiotype (Id) of the beta (2 leads to 6) fructosan-binding myeloma protein ABPC 48 (A48). Pretreatment of newborn BALB/c mice (at 1 d of age) with 0.01-10 microgram of affinity purified BALB/c anti-A48 Id antibody followed by immunization with BL 1-2 mo later produces an anti-BL response that expresses the A48 Id. This shows that A48 Id+ anti-BL clones belong to a normally silent fraction of the anti-BL repertoire. The activation of A48 Id+ anti-BL clones anti-A48 Id antibody is specific because the pretreatment of newborn mice with anti-MOPC 384 Id antibody, followed by immunization with BL, does not lead to its activation. Moreover, pretreatment of mice with anti-A48 Id antibody does not alter the MOPC 460 Id+ component of the anti-TNP response. It is also important to note that the activation of the A48 Id+ clone in pretreated mice requires subsequent immunization with BL.

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Dilevalol: A Selective Beta-2 Adrenergic Agonist Vasodilator with Beta Adrenergic Blocking Activity

The Journal of Clinical Pharmacology ◽

10.1002/j.1552-4604.1989.tb03280.x ◽

1989 ◽

Vol 29 (12) ◽

pp. 1057-1068 ◽

Cited By ~ 6

Author(s):

J. David Wallin ◽

William H. Frishman

Keyword(s):

Adrenergic Agonist ◽

Beta Adrenergic ◽

Blocking Activity ◽

Beta 2 ◽

Adrenergic Blocking

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The Response of Testes Cells to Low Level, Single dose Helium Particle Irradiation

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100053929 ◽

1982 ◽

Vol 40 ◽

pp. 252-253

Author(s):

D.E. Philpott ◽

W. Sapp ◽

C. Williams ◽

J. Stevenson ◽

S. Black ◽

...

Keyword(s):

Stem Cell ◽

Single Dose ◽

B Cell ◽

Cell Survival ◽

Spermatogonial Stem Cell ◽

Low Doses ◽

Particle Irradiation ◽

Stem Cell Survival ◽

Irradiation Injury ◽

Radio Sensitivity

Spermatogonial stem-cell survival after irradiation injury has been studied in rodents by histological counts of surviving cells. Many studies, including previous work from our laboratory, show that the spermatogonial population demonstrates a heterogeneous response to irradiation. The spermatogonia increase in radio-sensitivity as differentiation proceeds through the sequence As - Apr - A1 - A2 - A3 - A4 - In - B. The stem (As) cell is the most resistant and the B cell is the most sensitive. The purpose of this work is to investigate the response of spermatogonial cell to low doses (less than 10 0 rads) of helium particle irradiation.

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Potentiation of bromotrichloromethane hepatotoxicity in male rats exposed to 10 ppm dietary chlordecone: Electron Microscopic and biochemical study

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100158972 ◽

1990 ◽

Vol 48 (3) ◽

pp. 284-285

Author(s):

O. M. Faroon ◽

R. W. Henry ◽

M. G. Soni ◽

H. M. Mehendale

Keyword(s):

Free Radical ◽

Biochemical Study ◽

Prior Exposure ◽

Male Rats ◽

Cellular Injury ◽

Low Doses ◽

Mixed Function Oxidase ◽

Electron Microscopic ◽

Potent Inducer ◽

Cellular Energy

Previous work has shown that mirex undergoes photolytic dechlorination to chlordecone (CD) (KeponeR) in the environment. Much work has shown that prior exposure to nontoxic levels of CD causes potentiation of hepatotoxicity and lethality of CCl4, BrCCl3 and other halomethane compounds. Potentiation of bromotrichloromethane hepatotoxicity has been associated with compounds that stimulate the activity of hepatic mixed-function oxidase (MFO). An increase in the metabolism of halomethane by the MFO to a free radical initiates peroxidative decomposition of membranal lipids ending in massive cellular injury. However, not all MFO inducers potentiate BrCCl3 hepatotoxicity. Potentiation by much larger doses of phenobarbital is minimal and th at by a more potent inducer of MFO, mirex, is negligible at low doses. We suggest that the CD and bromotrichloromethane interaction results in a depletion of cellular energy and thereby reducing the cellular ability to undergo mitosis.

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