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Biomedical subjects

F Welsch

Publications and source records attributed to F Welsch.

At least 73 records · Page 4Linked to original sources
PubMed1979

Release of human chorionic somatomammotrophin from isolated perfused lobules and superfused fragments of term placenta: spontaneous liberation and the effects of cholinergic drugs, dibutyrylcyclic adenosine monophosphate and calcium.

Single isolated lobules from term placentae were bilaterally perfused with Earle's solution, and the release of human chorionic somatomammotrophin (HCS) was measured by radioimmunoassay. HCS was secreted almost exclusively to the maternal side. Concentrations released at the beginning of perfusions were quite similar to established maternal blood values (up to 10 microgram HCS/ml). Secretion then continued for at least 3 hours at a fairly linear rate. Acetylcholine, a prominent constituent of the noninnervated human placenta, and other cholinergic drugs failed to alter this pattern of hormone output in both intact lobules and dynamically superfused placental fragments. The ability of the placenta to respond to alterations in the perfusion environment was verified by stimulating the HCS secretion with 1 mM dibutyryl cyclic adenosine monophosphate and by modifying calcium concentrations. High calcium (10 mM CaCl2) led to a sustained increase of HCS release.

Bucladesine↗
PubMed1976

Effects of drugs on the uptake of acetylcholine by human term placenta fragments.

An active concentrative component of the ACh accumulation in fragments of human term placenta followed kinetics predicted by the Michaelis-Menten equation (Km greater than 15 mM). This process was competitively inhibited by choline or hemicholinium-3, suggesting the possibility that a common carrier existed. Morphine reduced the 3 H-ACh uptake competitively. Imipramine, desmethylimipramine, haloperidol and chlorpromazine decreased the concentration ratios. This effect was uncompetitive with respect to chlorpromazine. Compared to drug actions on the ACh uptake in innervated tissue drug effects in the placenta were much less predictable for various classes of compounds.

Acetylcholine↗
PubMed1976

Acetylcholine induced alterations of 32Pi incorporation into phospholipids: lack of effects in human term placenta.

Fragments of noninnervated human placenta, a tissue rich in acetylcholine were incubated with 32Pi and drugs which modify cholinergic functions. The incorporation of 32Pi into placental polar phospholipids was measured in the presence or absence of 1X10(-4)M exogenous ACh. Particular attention was paid to phosphatidic acid, phosphatidyl inositol and phosphatidyl choline. There was no change in the intensity of labelling of any of the phospholipids due to the presence of ACh.

Acetylcholine↗
PubMed1975

Urinary steroids in the measurement of aging and of atherosclerosis.

Several studies conducted by the authors' group have shown that urinary steroid measurements are a valuable aid in differentiating the normal aging process, the pronounced aging associated with increased risk to coronary heart disease, and the deviations associated with myocardial infarction. Data are presented on 428 men in the age range of 30-70 years. The study design most effective in elucidating aging and disease patterns involves selection of subjects from a wide age range. Data on persons identified as clinically normal can be used to describe physiologic aging. Once this is determined, data on persons with disease can be used to identify abnormalities of aging associated with the clinical conditions studied. This approach offers a potential method for differentiating between aging effects and disease effects. The foregoing findings led to the development of an Index of Aging in males, based on combined serum lipid and urinary steroid values. This Index may be a means of differentiating between normal aging and the deviations seen in atherosclerosis and myocardial infarction. Current studies are directed toward extending these observations.

Adult↗
PubMed1972

Paraoxon: effects on rat brain cholinesterase and on growth hormone and prolactin of pituitary.

Cholinesterase activity of brain and content of growth hormone and prolactin in the pituitary were compared after short-term (3 days) and long-term (14 days) treatment with paraoxon in male and female rats. Within 3 days cholinesterase activity was reduced to between 5 and 15 percent of that in controls. The content of growth hormone in the pituitary was increased in long-term experiments by 50 percent. This increase in paraoxon-treated animals-suggests a possible role of a cholinergic mechanism in the regulation of growth hormone secretion.

Animals↗